Malnutrition in Children Over 1 Year of Age (Protein-Energy Malnutrition): Clinical Guidelines

List of Abbreviations

PEM – protein-energy malnutrition

BEE – basal energy expenditure

WHO – World Health Organization

FM – fat mass

GI – gastrointestinal tract

BMI – body mass index

ARFID – avoidant/restrictive food intake disorder

CT – clinical trials

Med – medication

ICD-10 – International Classification of Diseases, 10th Revision

BW – body weight

M – malnutrition

BSVD – basic variant of standard diet

MUAC – mid-upper arm circumference

AMC – arm muscle circumference

ONS – oral nutritional support

ICU – intensive care unit

PN – parenteral nutrition

ASD – autism spectrum disorder

РКИ – randomized controlled trial

BW – body weight

RFS – refeeding syndrome

SIBO – small intestinal bacterial overgrowth

CRP – C-reactive protein

ESR – erythrocyte sedimentation rate

TSFT – ¹subscapular skinfold thickness

TSFT – triceps skinfold thickness¹

FAO – Food and Agriculture Organization of the United Nations

ABW – actual body weight

CVC – centrally inserted central venous catheter (such as Hickman/Broviac) or peripherally inserted central venous catheter (including multichannel) / central venous catheterization sets with a multichannel antimicrobial-coated catheter, etc.

Port system – Implantable infusion/injection port/catheter*** or implantable infusion/injection port***

PEG – percutaneous endoscopic gastrostomy

EN – enteral nutrition

ENT – enteral tube nutrition

ASPEN – American Society for Parenteral and Enteral Nutrition

ESPEN – European Society for Clinical Nutrition and Metabolism

ESPGHAN – European Society for Paediatric Gastroenterology, Hepatology and Nutrition

MCT – medium-chain triglycerides

MUAC – mid-upper arm circumference

UNU – United Nations University

Z-score (or SD) – a measure of the relative dispersion of an observed or measured value, showing how many standard deviations away it is from the mean

Note:

¹ – According to Order No. 804n of the Russian Ministry of Health dated October 13, 2017, "On Approval of the Nomenclature of Medical Services", the service is designated as "Measurement of skin fold thickness (plicometry)"; it should be noted that the correct definition is skin-fat fold

Terms and Definitions

Body mass index (BMI) – an index that allows assessing the degree of correspondence between a person's weight and height, and indirectly judging whether the weight is underweight, normal, or overweight. BMI = body weight / height² (kg/m²).

Avoidant/restrictive food intake disorder (ARFID) – an eating disorder characterized by avoidance or restriction of food intake, leading to energy and/or nutritional deficiency, negatively affecting the child's development and somatic health, and/or causing significant impairment in important areas of functioning (family, social, academic, professional, or others).

Macronutrients – dietary substances (proteins, fats, and carbohydrates) required by humans in quantities measured in grams, providing plastic, energy, and other needs of the body.

Micronutrients – dietary substances (vitamins, minerals, and trace elements) found in food in very small amounts – milligrams or micrograms. They are not sources of energy, but are involved in the assimilation of food, regulation of functions, and the processes of growth, adaptation, and development of the body.

Malnutrition is defined as deficiencies, excesses, or imbalances in a person's intake of energy and/or nutrients. The term "malnutrition" covers two broad groups of conditions. One is undernutrition, which includes stunting (low height for age), wasting (low weight for height), underweight (low weight for age), and micronutrient deficiencies or insufficiencies (a lack of important vitamins and minerals). The other is overweight, obesity, and diet-related noncommunicable diseases (including cardiovascular disease, cancer, stroke, and diabetes) [176].

Undernutrition is a pathological condition caused by a discrepancy between nutrient intake and expenditure, leading to weight loss and changes in the body's compositional structure. This condition arises from inadequate intake or impaired assimilation/absorption of food, resulting in altered body composition (reduction of muscle and fat mass) and body cell mass, decreased immunity, physical and mental functioning, and a poorer prognosis for the underlying disease.

Undernutrition in children is a condition caused by inadequate intake, consumption, or assimilation of nutrients, leading to weight loss and changes in body composition, immune response, impaired physical and psychomotor development, and worsening clinical outcomes of the disease [1, 2].

Nutritional support is the process of providing substrate support to patients who are unable to receive adequate natural nutrition, supplying all essential nutrients for life through specialized methods and artificially created nutritional formulas (NFs) tailored for various purposes [3].

Nutritional status (alimentary, trophic status) is a complex of clinical, anthropometric, and laboratory parameters characterizing a person's health status and physical development, the body's supply of energy, nutrients, and biologically active substances, reflecting food assimilation processes at the cellular and subcellular levels, and ensuring the realization of the body's adaptive potential. – 2013. – National Association of Clinical Nutrition.

Sarcopenia is the reduction of muscle mass, strength, and function. Pediatric sarcopenia is associated with disease-related factors.

Small intestinal bacterial overgrowth (SIBO) is a pathological condition of primary or secondary origin characterized by an increased number and/or altered composition of the microbiota in the small intestine, manifesting as impaired functions of the intestinal microbiota, digestion, and the development of malabsorption [4].

Oral nutritional support is a method of organizing therapeutic or prophylactic nutrition that involves the ingestion of an enteral product through the oral cavity by swallowing.

Protein-energy malnutrition (PEM) is a nutrition-related condition caused by significant duration and/or intensity of predominantly protein and/or energy deprivation, manifested by weight loss and/or growth retardation and complex disruption of metabolic processes, water-electrolyte balance, decreased immune response, and dysfunction of the gastrointestinal tract and other organs and systems.

Cachexia is a multifactorial syndrome defined by ongoing loss of skeletal muscle mass (with or without loss of fat mass).

Kwashiorkor is a condition caused by severe protein deficiency with adequate energy intake. It is most common in certain regions of the world where dietary protein is reduced in infants and children.

Marasmus is a form of severe undernutrition associated with a deficiency in the intake of energy and all macro- and micronutrients.

Enteral nutrition is a type of dietotherapy (nutritional support) that involves the administration of enteral nutrition products via introduction into the gastrointestinal tract in order to fully meet the body's nutrient requirements, including through combination with other types of dietotherapy.

Parenteral nutrition is a type of nutritional support involving the administration of nutritional substrates into the vascular bed, bypassing the gastrointestinal tract, to fully or partially meet the body's requirements.

Combined nutritional support is a type of nutritional support involving the administration of nutritional substrates via both parenteral and enteral routes.

Tube enteral nutrition is a method of organizing enteral nutrition via a tube or stoma into the gastrointestinal tract distal to the oral cavity [5].

Enteral nutrition food products are liquid or dry (reconstituted to ready-to-use) dietary foods for special medical purposes or dietary prophylactic nutrition intended for oral consumption directly or via tube feeding when the body's needs for nutrients and energy cannot be met in the usual way.

Hypercaloric enteral nutrition food product – an enteral nutrition food product containing more than 1 kcal/1 ml of the product reconstituted to ready-to-use or per 100 ml of the liquid product.

Isocaloric enteral nutrition food product – an enteral nutrition food product containing 1 kcal/1 ml of the product reconstituted to ready-to-use or per 100 ml of the liquid product.

Hypocaloric enteral nutrition food product – an enteral nutrition food product containing less than 1 kcal/1 ml of the product reconstituted to ready-to-use or per 100 ml of the liquid product.

Hypernitrogenous enteral nutrition product – an enteral nutrition product containing more than 5.1 g of protein per 100 cm³ of reconstituted product ready for consumption or per 100 ml of liquid product.

Isonitrogenous enteral nutrition food product – an enteral nutrition food product containing from 3.5 to 5.0 g of protein per 100 ml of the product reconstituted to ready-to-use or per 100 ml of the liquid product.

Low-nitrogen enteral nutrition product – an enteral nutrition product containing less than 3.5 g of protein per 100 ml of reconstituted ready-to-use product or per 100 ml of liquid product.

Hyperosmolar enteral nutrition product – an enteral nutrition product with an osmolarity greater than 300 mOsm per 100 ml of product reconstituted to ready-to-eat form or per 100 ml of liquid product.

Hypoosmolar enteral nutrition product – an enteral nutrition product with an osmolarity of less than 280 mOsm per 100 ml of product reconstituted to ready-to-eat form or per 100 ml of liquid product.

Standard enteral nutrition products – dietary preventive and/or dietary therapeutic foods for adults and children over one year of age, intended for tube feeding and/or oral consumption as the sole source of nutrients and energy, and which can also be used as an additional source in case of malnutrition or the risk of its development, when normal food intake is impossible or limited.

Metabolically targeted enteral nutrition product – an enteral nutrition product with an adapted chemical composition that takes into account the most significant metabolic disorders caused by a specific degree of organ failure.

Polymeric enteral formulas – enteral nutrition products containing intact protein derived from milk (whey protein, casein protein) or plant sources (soy and pea protein).

Oligomeric enteral nutrition product (semi-elemental formula) – an enteral nutrition product with a hydrolyzed protein component.

Elemental formula – an amino acid-based enteral nutrition product.

Modular enteral nutrition products – products comprising one or more nutrients, used as a supplement to the main diet to meet the individual needs of the patient.

Specialized medical nutrition product – food products with a defined chemical composition, energy value, and physical properties, with proven therapeutic efficacy, which exert a specific effect on the restoration of body functions impaired or lost as a result of a disease, the prevention of these disorders, and the enhancement of the body's adaptive capabilities.

Partial or mixed PN – the additional parenteral administration of individual nutrients when enteral nutrition is limited.

Supplemental PN – the administration of individual nutrients during periods of increased demand (e.g., the additional prescription of amino acids when activation of reparative processes is required) [6].

Triceps skinfold thickness (TST) and subscapular skinfold thickness (SST) – measurements performed using skinfold calipers, representing one of the most accessible methods for assessing fat mass.

In accordance with Order of the Russian Ministry of Health No. 804n dated October 13, 2017, "On Approval of the Nomenclature of Medical Services," the service is designated as "Measurement of skinfold thickness (plicometry)"; it should be noted that the correct term is skin-fat fold thickness .

Mid-upper arm circumference (MUAC) is measured using a flexible tape measure on the non-dominant arm at the midpoint of the upper arm between the acromion and the olecranon process with an accuracy of 1 mm.

Arm muscle area – calculated using the formula: AMA = (MAC – π × TST)² / 4π.

Mid-upper arm circumference (MUAC) – a parameter based on measurement with a flexible tape measure at the level of the middle third of the non-dominant arm and TST. It can be used to determine body composition in children with malnutrition. It is calculated using the formula: [(MUAC (mm) = MAC (mm) - TST (mm) × 0.314)].

Physical development – the dynamic process of growth (increase in body length and weight, development of organs and body systems) and biological maturation of a child in accordance with childhood periods.

Height – as a dynamic process of increasing linear and volumetric body dimensions, reflects the systemic developmental process of the organism as a whole. The level of physical development is determined by height, as the most stable indicator.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Malnutrition in children – a condition caused by inadequate intake, consumption, or absorption of nutrients, leading to changes in body weight and composition, immunological resistance, decreased physical and psychomotor development, and worsening clinical outcomes of the disease [1, 2].

Comment

In the literature, the term for malnutrition in children has not yet been standardized.

In our country, the term "hypotrophy" was used for quite a long time for children of both the first year of life and early age (1–3 years).

The Joint FAO/WHO Expert Committee on Nutrition proposed the term "protein-energy malnutrition" (PEM). PEM is a nutrition-related condition caused by prolonged and/or intensive primarily protein and/or energy deprivation, manifested by weight and/or height deficit and complex impairment of body homeostasis in the form of altered basic metabolic processes, water-electrolyte imbalance, altered body composition, and impaired neural regulation [5].

In ICD-10, the term malnutrition is presented without criteria (E40–E46). At the same time, criteria are provided for the term PEM, which is frequently used in domestic practice as a substitute for the term malnutrition.

The term PEM has a narrower meaning compared to malnutrition, as it includes protein and energy deficiency without accounting for the deficit of other nutrients.

In foreign guidelines, the concept of malnutrition is distinguished from the term protein-energy malnutrition [1], given their semantic differences.

Malnutrition in childhood has specific diagnostic criteria because this period of ontogenesis is characterized by growth and development processes, the retardation of which can serve as a diagnostic criterion for malnutrition.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The problem of childhood malnutrition manifests differently across various countries. For instance, in developing countries, childhood malnutrition is a socio-political and social problem. In countries of Asia, Africa, and Latin America, more than 40 million children suffer from acute malnutrition annually; 45% of child mortality in these countries is associated with acute malnutrition. In economically developed countries, the significance of social factors—such as low population sanitary culture or adherence to certain diets (veganism, vegetarianism)—cannot be ignored either; however, childhood malnutrition in these countries is predominantly a problem of clinical medicine. It almost always affects children in risk groups (children with hereditary pathologies and developmental defects, premature infants, and children with chronic somatic and neurological conditions).

Malnutrition is classified as a multifactorial condition that includes: decreased nutrient intake, increased nutrient requirements against the background of systemic inflammatory processes, malabsorption, including due to nutrient losses or, as a rule, a combination of these factors.

Malnutrition occurs in any pathological condition that blocks intracellular metabolism: infectious-toxic, hypoxemic, hemocirculatory, enzymopathic, neuroendocrine, encephalopathic, etc. (Table 1).

The disease factor is associated with decreased nutrient intake due to hyporexia and/or feeding difficulties, altered metabolic needs, and the necessity of hospitalization.

Hospitalization serves as an additional risk factor for malnutrition if its duration exceeds 5 days [7].

Table 1. Diseases/conditions most frequently causing malnutrition

Note. GIT — gastrointestinal tract; CMP — cow's milk proteins; HIV — human immunodeficiency virus.

Against the background of inflammatory reactions, nutritional deficiency (ND) develops due to the activation of hypercatabolic and hypermetabolic processes, impaired nutrient utilization, and their metabolism. Of key importance is the altered balance of pro- and anti-inflammatory cytokines. Among pro-inflammatory cytokines, the role of tumor necrosis factor alpha, interleukin-1 beta, and IL-6 has been well studied [8, 9].

The progression of ND symptoms is closely associated with the development of small intestinal bacterial overgrowth (SIBO) syndrome. Maldigestion and malabsorption in ND create conditions for the excessive proliferation of the small intestine microbiota and are key triggering factors leading to the onset of SIBO. In SIBO, certain metabolic and immunological processes in the small intestine are disrupted, which exacerbate maldigestion and malabsorption, and also set the stage for the development of systemic inflammation:

• as a result of active carbohydrate breakdown, an excess of bacterial metabolism products is formed (e.g., H₂, CH₄, H₂S, CO₂), which cause the development of visceral hypersensitivity, abdominal bloating, and diarrhea;

• the amount of methane produced increases during the excessive proliferation of methanogenic archaea, which leads to slowed colonic motility and results in the development of abdominal bloating and constipation symptoms;

• low-grade inflammation is sustained by secondary bile acids (predominantly lithocholic acid) and fatty acid metabolites, leading to increased permeability of the small intestinal mucosal-epithelial barrier;

• secondary disaccharidase deficiency occurs due to damage to the enterocyte brush border, which exacerbates oligosaccharide maldigestion and subsequent monosaccharide malabsorption;

• microbial breakdown of amino acids and low-molecular-weight proteins in the small intestine is enhanced, leading to the development and aggravation of malabsorption;

• absorption of fats and fat-soluble vitamins is reduced as a result of excessive deconjugation of bile acid salts, which also worsens malabsorption;

• competition between the human body and the small intestine microbiota for vitamins B₁, B₂, B₃, B₅ and B₁₂ increases (due to an increase in bacteria utilizing these vitamins);

• the proportion of toxic metabolites synthesized by bacteria (ammonia, D-lactate, and bacterial peptidoglycans) increases, leading to impaired epithelial barrier permeability and enhanced bacterial translocation;

• The intensity of the local and systemic immune response increases due to an elevated pool of pro-inflammatory cytokines (IL-1a, IL-1b, IL-6, and tumor necrosis factor alpha TNF-α).

Due to an increase in the non-specific pro-inflammatory immune response and alterations in the gut microbiota composition SIBO exerts a negative impact on the course of ND and a number of other chronic non-communicable diseases [4].

Socioeconomic conditions that limit access to food and create an unfavorable psycho-emotional background of eating disorders contribute to the development of ND.

Malnutrition can frequently be observed in patients with mental disorders: anorexia, schizophrenia, bipolar disorder, and others. In recent years, particular attention has been drawn to the widespread problem of avoidant/restrictive food intake disorder in children (ARFID). ARFID is frequently found in patients with developmental disorders, such as autism spectrum disorders (ASD). A study in a large cohort of individuals with autism revealed avoidant/restrictive eating patterns in 21% of participants. Among children diagnosed with ARFID, ASD occurs in 8.2–54.8% of children, according to various studies [201]. More than half of patients with ARFID also have other psychiatric diagnoses. Anxiety, depression, sleep disorders, and learning disorders are common co-occurring problems in ARFID [201]. Diagnosis of ARFID is carried out, inter alia, using specially designed tests for children and parents.

Malnutrition has a pronounced negative impact on the health of children and adolescents, increasing the risk of diseases, worsening their course and prognosis, and hindering the realization of existing genetic potential while reducing the quality of life.

ND has long-term consequences and affects an individual's health throughout ontogenesis.

In the course of ND, energy balance shifts from carbohydrate to lipid; to ensure the vital activity of the organism, proteins are involved in energy production, which leads to a negative nitrogen balance. In malnutrition, especially of long duration, non-specific dystrophic changes occur in the body, accompanied by a decrease in food tolerance.

As a result, children with malnutrition are 2.5 times more likely to require hospitalization, which leads to a more than 3-fold increase in healthcare costs [10].

1.3 Epidemiology of the Disease or Condition

Malnutrition (ND) in children continues to be a pressing global health issue. According to WHO data, globally in 2022, wasting was identified in 45 million (6.8%) children under 5 years of age, including severe wasting in 13.6 million, and stunting was observed in 148.1 million (22.3%) children [11].

In economically developed countries of the European Union, the prevalence of ND among patients seeking medical care in pediatric clinics ranges from 2.4% to 26% [12, 13].

According to a meta-analysis of 22 published reviews, in pediatric surgical hospitals, the risks of developing nutritional deficiency occurred in 25–90% of hospitalized patients [14, 15].

The prevalence of disease-associated ND depends on the nature of the nosology. Oncological patients, as well as those with congenital central nervous system pathologies, hold the leading positions, among whom ND accounts for 40% to 80% [16].

Based on the results of assessing the prevalence of underweight in children and adolescents in Russia using a meta-analysis of published data from scientific research for 2011–2023, it was established in the Russian Federation that the occurrence of underweight among various pediatric populations varies from 3% to 29%; malnutrition — from 0.6% to 12.5% [17].

Protein-energy malnutrition is one of the variants of malnutrition, which can be represented by a broader symptom complex and is often accompanied by other nutritional deficiencies, such as micronutrient deficiencies, etc. Iron, fat-soluble vitamin, and zinc deficiencies are most frequently detected in such patients. Protein-energy malnutrition may also feature deficiencies of water-soluble vitamins, minerals, and trace elements, which is determined by both regional characteristics and the duration of malnutrition [18].

According to a study conducted at the National Medical Research Center for Children's Health of the Russian Ministry of Health, malnutrition associated with somatic, neurological, and surgical diseases has a high frequency of 14.6% and depends on the nosology and age of the children. A high frequency of ND is identified in patients with nervous system diseases (43.8%), cardiac diseases (33.3%), and GI diseases (19.5%). The presence of ND is an unfavorable factor increasing the duration of hospitalization, which is 1.3 times higher than in children with adequate nutritional status [19].

A special group consists of patients with nervous system diseases.

These patients show hyporexia, appetite disturbances, feeding difficulties (oromotor dysfunction), and gastrointestinal disorders (enzymopathies, malabsorption, including iatrogenic, GER, etc.) (Appendix A3.1).

A study by Gandaeva L.A. (2016) demonstrated that undernutrition was detected in nearly half (45%) of children with chronic heart failure (CHF). Acute undernutrition was observed in 55% of children with cardiomyopathies (CMP), in 28% of patients with congenital heart defects (CHD), while chronic undernutrition occurred in 3% and 14% of children, respectively [20].

Among patients with colonic agangliosis admitted for surgical treatment, undernutrition was identified in 54% of patients, with acute undernutrition present in 38% and chronic undernutrition in 16% of children [21].

Sokolov I. established that upon hospital admission, undernutrition was detected in 60% of children with cystic fibrosis, with the acute form of undernutrition in 41% and the chronic form in 19% [22].

According to a study by Fedorushkina N.A. (2023), undernutrition was detected in the majority of children with spastic forms of cerebral palsy (53%: mild 6.2%, moderate 8.8%, severe 38%), and growth retardation in 25% of patients. In patients with severe motor impairments (GMFCS IV-V), undernutrition was 2.2 times more frequent (p < 0.001) than in children with mild and moderate motor impairments (GMFCS I-III), at 72% and 32%, respectively [23].

1.4 Features of Coding the Disease or Condition

E43 - Severe protein-energy malnutrition, unspecified

E44 - Protein-energy malnutrition of moderate and mild degree

E44.0 - Moderate protein-energy malnutrition

E44.1 - Mild protein-energy malnutrition

E45 - Retarded development following protein-energy malnutrition

E46 - Unspecified protein-energy malnutrition

1.5 Classification of the disease or condition

Currently, there is no consensus on the definition of undernutrition in children. This partially explains the discrepancies in undernutrition prevalence statistics and affects treatment outcomes, as it precludes the timely identification of children at risk for undernutrition or suffering from undernutrition. The WHO guidelines on the prevention and management of acute malnutrition in children under 5 years of age (2023) use the term "acute malnutrition", which is used in national health systems and international non-governmental organizations to characterize wasting (weight-for-height/BMI-for-age < -2SD) [24].

Chronic undernutrition is defined as undernutrition persisting for more than 3 months [1, 2]. Decreased growth velocity and short stature are additional criteria for chronic undernutrition (height-for-age Z-score < -2SD) [25].

By etiology:

• Primary undernutrition is caused by inadequate nutrient intake [26, 27].

• Secondary undernutrition develops against the background of an underlying disease, including the use of medications that impair nutrient absorption and affect metabolism (secondary undernutrition [or disease-related malnutrition] is a state resulting from inadequate or unbalanced nutrition that leads to clinically significant adverse effects on tissue function, anthropometric parameters, and/or body composition, with subsequent impact on health) [1].

The characteristics of children's nutritional status based on anthropometric measurements are presented in Table 2 [26, 28, 29, 30, 31].

Table 2. Characteristics of children's nutritional status based on anthropometric measurements

By severity of undernutrition (PEM):

Undernutrition/risk of undernutrition (mild) - weight loss or lack of weight gain in a child resulting in measured weight and BMI falling below the mean for the reference population by ≥ 1, but less than 2 standard deviations.

Moderate - weight loss or lack of weight gain in a child resulting in measured weight and BMI falling below the mean for the reference population by ≥ 2 standard deviations, but less than 3 standard deviations.

Severe - severe weight loss or lack of weight gain in a child resulting in measured weight and BMI falling at least 3 or more standard deviations below the mean for the reference population (or a similar reduction in weight reflected by other statistical methods).

1.6 Clinical presentation of the disease or condition

The main clinical manifestations of undernutrition are weight loss and/or delayed weight and height gain in the child, accompanied by alterations in basic metabolic processes, water-electrolyte balance, immune system suppression, gastrointestinal dysfunction, and dysfunction of other organs and systems.

Clinical manifestations of undernutrition vary depending on the degree of severity.

Undernutrition (mild degree) is characterized by thinning of the subcutaneous adipose tissue across all areas of the child's body, predominantly on the abdomen, along with decreased tissue turgor and muscle tone. Moderate pallor of the skin and mucous membranes, as well as reduced skin elasticity and suppleness, are noted. The child's growth is not lagging behind the norm, and the weight gain curve is flattened. General well-being is satisfactory; anxiety and sleep disturbances are observed. Indicators of immunological reactivity are normal or slightly reduced.

In moderate degree, subcutaneous adipose tissue is absent on the abdomen, sometimes on the chest, and the subcutaneous fat layer is sharply thinned on the extremities while persisting on the face. The skin is pale-grayish, dry, and gathers into folds. Tissue turgor, muscle mass, and muscle tone are significantly reduced. Signs of rickets and other hypovitaminoses are frequently present. There is a tendency towards growth retardation. The weight gain curve is flat, appetite is reduced, and food tolerance is lowered. Irritability, weakness, anxiety, or lethargy and apathy are characteristic. Sleep is restless, and thermoregulation is impaired. Anemia is concomitant. Cardiac auscultation reveals functional murmurs. Immunological reactivity is reduced, and local inflammatory diseases may develop.

Severe degree is characterized by extreme wasting. Subcutaneous adipose tissue is absent on the abdomen, torso, and extremities; the fat layer on the face is sharply thinned or practically absent. The skin is pale-gray, dry, and skin folds do not smooth out. Tissue turgor is absent, and deep muscle hypotonia or atonia is noted. Marked growth retardation is accompanied by a negative weight gain curve. Food tolerance is very low. Neurological status: lethargy, adynamia, reduced response to the environment. Thermoregulation is consistently impaired (decreased body temperature alternates with rises to subfebrile levels). Due to decreased immunological reactivity, foci of infection are almost always present. Anemia is present. Cardiovascular system findings include muffled heart sounds, bradycardia, and decreased blood pressure (BP). Flatulence and loose stools are concomitant.

2. Diagnostics, medical indications and contraindications for diagnostic methods

When prescribing enteral/parenteral nutrition, as well as when choosing the composition of nutrient formulas/solutions for intravenous administration and determining dosages, monitoring the degree of nutritional status impairment is necessary.

At the first stage, risk groups for undernutrition are identified through history taking and clinical examination of patients. Patients assigned to the risk group undergo a more detailed nutritional assessment and receive appropriate treatment as needed.

Nutritional status assessment is performed using indicators that together characterize the patient's nutritional status and nutrient requirements:

The diagnosis of undernutrition in children over one year of age is established based on medical history and physical examination data, taking into account the results of laboratory and instrumental examinations [26, 32, 33].

Criteria for diagnosing/establishing the condition of undernutrition:

The diagnosis of undernutrition in children older than 1 year and its severity should be established based on the results of assessing standard anthropometric deviation scores (SD) - Z-scores for weight-for-age and BMI-for-age [34] in accordance with the recommendations of the Russian Ministry of Health [31].

Comments: the severity of malnutrition is assessed using body weight indicators expressed in standard deviations (Z-scores) from the mean for the reference population. Failure to gain weight or weight loss in children, when one or more previous weight measurements are available, is an indicator of malnutrition. A single weight measurement is not considered definitive and requires confirmation [27, 35].

Tables are provided in Appendix A3.2.

The diagnosis of malnutrition in pediatric patients older than one year is established when the BMI-for-age, weight-for-age, weight-for-height, or MUAC-for-age Z-score is < -2 SD, or (if repeated anthropometric measurements are available) a downward trend of the indicator curve by ≥ 1 SD is observed (Table 3). Measurement and evaluation of MUAC is preferred in the presence of peripheral edema, ascites, hydrocephalus, or during steroid therapy—situations where body weight does not reflect nutritional status—as well as in children in the ICU or postoperatively when weighing is impossible.

Weight loss is used as the main clinical indicator of malnutrition in children older than 2 years: 5% to 7.5% of usual body weight is considered mild, 7.5% to 10% moderate, and > 10% severe [2].

Whenever possible, all 4 parameters should be used, prioritizing BMI-for-age or weight-for-height; if height cannot be measured, the weight-for-age ratio is considered the primary criterion

Table 3. Anthropometric parameters of moderate/severe malnutrition in children with diseases [1].

As an additional criterion for malnutrition, as well as in cases of difficulty using standard anthropometry, skinfold thickness measurement (skinfoldometry) using a caliper (TSFT) should be used for diagnosis [36, 37, 38].

Comments: the diagnostic criterion is a TSFT value < -2 SD.

To clarify the severity of disorders associated with malnutrition, based on MUAC measurement (at the midpoint of the upper arm of the non-dominant hand) and TSFT, the mid-upper arm muscle circumference (MUAMC) can be calculated [MUAMC (mm) = MUAC (mm) – 3.14 × TSFT (mm)] [38, 39].

MUAMC correlates with BMI and somatic protein pool reserves in the body.

The screening method for detecting malnutrition in children is the MUAC (Mid-Upper Arm Circumference) method, based on measuring the circumference of the middle third of the upper arm using a special tape (MUAC tape).

As a method complementing standard anthropometric approaches, MUAC is approved by ASPEN and ESPGHAN [2, 37, 40]. The method has been validated in the Russian Federation as a diagnostic method for malnutrition in children [41].

The high reproducibility of the method is important when conducting surveys in organized groups and for monitoring nutritional status.

Nutritional status assessment also takes into account:

Also taken into account:

- assessment of actual dietary intake;

- instrumental diagnostics (determination of the percentage ratio of water, muscle, and fat tissue using bioimpedance analysis (determination of body composition components using bioimpedance analysis - body composition analysis)) [42, 43].

- laboratory parameters (protein metabolism parameters may be assessed: blood total protein test, blood albumin test, serum transferrin test).

Note: currently, there are no optimal biomarkers for assessing protein-energy malnutrition. Serum albumin and prealbumin are well-known acute-phase reactants that, regardless of the body's nutritional reserves, decrease during systemic inflammatory response, liver dysfunction, gastrointestinal and renal losses, and hydration disorders. From a modern perspective, serum albumin and prealbumin do not reflect the loss of muscle mass or tissue proteins and, consequently, are not adequate indicators for diagnosing malnutrition. These parameters cannot be used as markers of nutritional status, but remain independent risk factors for complications and are evaluated in addition to a thorough clinical examination [44].

The main parameters for assessing nutritional disorders are presented in Appendix 5 of the Order of the Russian Ministry of Health No. 330 dated August 5, 2003, "On measures to improve therapeutic nutrition in healthcare institutions of the Russian Federation".

2.1 Complaints and Anamnesis

Comments: characteristic complaints include changes in appetite (decrease, selectivity), dyspeptic symptoms, weight loss or failure to thrive (weight and height gain), weakness, fatigue, and decreased physical activity. The presence of all symptoms is not mandatory.

History reveals conditions associated with nutritional risks, reduced food intake, prolonged feeding time, weight loss (or growth faltering), and growth retardation.

It is recommended to evaluate the history for recurrent respiratory infections, nasal congestion, voice changes, and coughing during meals in children with neurological disorders in order to assess for dysphagia.

It is important to establish the onset of symptoms and their dynamics.

2.2 Physical Examination

Assessment of body weight, height, and weight and height gains is of fundamental importance for identifying malnutrition.

Comments: based on the results of height and weight measurements, the BMI (Body Mass Index calculation) is calculated.

Anthropometric measurements are evaluated using standardized approaches – the WHO Anthro software for children under 5 years of age, and WHO AnthroPlus for children aged 5 to 17 years [46].

Evaluation is carried out using the following parameters: body weight, height, head circumference (for children under 2 years of age). WHO growth chart tables (2007) are presented in Appendix A3.2, and normal weight gain ranges at different ages are provided in Appendix A3.3.

As additional criteria, the determination of the mid-upper arm circumference (Appendix A3.4), skinfold thickness measurement (skinfold calipermetry) – over the triceps (Appendix A3.5). Anthropometric percentiles for mid-upper arm circumference (MUAC), mid-arm muscle circumference (MAMC), and triceps skinfold thickness are presented inAppendix A3.6. The Slaughter M.H. et al. (1988) equation for determining body fat percentage based on triceps and subscapular skinfold measurements is presented inAppendix A3.7.

Studies are performed regularly, in dynamics. The frequency and scope are determined by the patient's condition.

Children with certain health conditions have different growth assessment parameters, for example, in Down syndrome, Turner syndrome, Russell-Silver syndrome, Cornelia de Lange, Noonan syndrome, Prader-Willi syndrome, achondroplasia [47], and cerebral palsy [48] (see relevant guidelines) [37, 49, 50, 51, 52].

Linear growth can be assessed using segmental measurements, i.e., knee height, lower leg length, or arm length, in patients for whom standard anthropometry cannot be used [53]. (Formulas for calculating height are presented in Appendix A3.8, and the lower leg length measurement technique and formula for determining a child's height are in Appendix A3.9).

Comments: it should be noted that the listed clinical manifestations are not pathognomonic.

During the clinical evaluation, attention should be paid to potential causes and signs of weight loss and malnutrition, as well as conditions that may affect food intake.

The studies are carried out regularly, dynamically. The frequency and scope are determined by the patient's condition at least once every 6 months; an individual monitoring program is drawn up for children with severe nutritional insufficiency [37].

Comments: currently, the Russian-language version of the STRONGkids screening tool has been adapted and validated in the Russian Federation, which is used to determine nutritional risk groups and the need for specialized enteral nutrition products (see Appendix G1).

Comments: a decrease in the indicator > 1 Z-score (weight-for-age, weight-for-height, BMI-for-age) indicates the need for further nutritional status assessment.

For more details, see the sections "Monitoring of a patient with nutritional insufficiency on enteral nutrition and control parameters of parenteral nutrition".

2.3 Laboratory Diagnostics

Comments: special attention should be paid to the hemoglobin level (blood total hemoglobin test), erythrocyte sizing, determination of mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration.

The study is also carried out dynamically during treatment and follow-up; the frequency is determined individually, but at least once every 6 months, or more frequently according to indications; an individual monitoring program is drawn up for children with severe nutritional insufficiency.

If abnormalities are detected, further investigations and treatment should be carried out within the framework of relevant clinical guidelines.

The impact of malnutrition on cellular immunity can be assessed by measuring the total lymphocyte count (differential white blood cell count). Impairment of cellular immunity is usually observed when the lymphocyte count drops below 1000/mm³_.

Comments: the study is performed at least once every 6 months, or more frequently according to indications; an individual monitoring program is drawn up for children with severe nutritional insufficiency.

Comments: determination of blood or plasma prothrombin (thromboplastin) time is used as an indirect indicator to measure vitamin K levels. Supplementation with specific fat-soluble vitamins is indicated if serum concentrations are low or prothrombin time is prolonged.

Water-soluble vitamin deficiency is less common and their levels should be measured only when clinically indicated and technically feasible.

Comments: systemic inflammation, including common respiratory infections, can affect the concentrations of many vitamins, making the interpretation of results difficult. If an elevated CRP level / elevated ESR / decreased blood albumin level is detected, repeat tests should be performed or alternative approaches used. The study is performed dynamically, according to clinical necessity.

Laboratory diagnosis of central venous catheter-related complications

• If symptoms such as fever (body temperature above 38.0°C), metabolic acidosis, thrombocytopenia, and unstable blood glucose levels are detected in a child receiving parenteral nutrition, it is recommended to immediately perform blood cultures for aerobic and anaerobic microorganisms and fungal infections (central venous blood collection, microbiological [culture] test of blood for sterility, microbiological [culture] test of blood for molds, microbiological [culture] test of blood for yeasts, microbiological [culture] test of blood for obligate anaerobic microorganisms) in order to diagnose / rule out infectious complications associated with central venous catheters [125].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comment: in accordance with the recommendations of the Surviving Sepsis Campaign (SSC), blood cultures must be drawn from the central venous catheter and a peripheral vein, as well as from other body fluids (depending on the clinical situation in accordance with sepsis guidelines) that may be the source of infection before starting anti-infective therapy [140]. According to literature, the most frequent causative agents of catheter-related bloodstream infections are Gram-positive bacteria—staphylococci and enterococci; members of the Enterobacteriaceae family are of much lesser importance. Central venous catheter fungal infections and persistent hyperthermia with positive blood cultures are indications for central venous catheter removal.

Antimicrobial therapy is carried out in accordance with sepsis guidelines.

Laboratory diagnosis of parenteral nutrition complications related to water and sodium overload

• In the early stage of parenteral nutrition, at least once a day, it is recommended to monitor blood and urine biochemical parameters: blood glucose test, blood electrolyte panel (blood sodium test, blood potassium test, blood chloride test, blood total calcium test, blood ionized calcium test, blood inorganic phosphorus test) and urine tests (urine calcium test, urine potassium test, urine sodium test) to prevent water and sodium overload [118, 119, 120, 121].

CGR CLOE 5Level of Clinical Guidance - C (Level of Evidence - 5)

Comments: if abnormalities are detected, prompt and adequate correction is required (see section "Electrolytes and Minerals").

The frequency of tests included in monitoring is determined by the clinical situation.

2.4 Instrumental Diagnostics

Specific instrumental methods for diagnosing malnutrition are not agreed upon by experts, but they help clarify the severity of nutritional status disorders and determine body composition (skinfold thickness measurement [plycometry] [caliperometry, skinfold thickness], bioelectrical impedance analysis [determination of the percentage of water, muscle, and fat tissue using a bioimpedance analyzer]).

Comments: body mass index is an approximate indicator because it does not reflect changes in various fractions of body composition (lean and fat tissue). The most informative in this regard are data from caliperometry and bioelectrical impedance analysis (determination of the percentage of water, muscle, and fat tissue using a bioimpedance analyzer), which reflect body composition and allow for the analysis of compositional changes in body mass (volume of lean, muscle, and fat mass), which is very important in clinical practice and when choosing diet therapy tactics.

Caliperetry is an affordable method involving the measurement of skinfold thickness (plicometry) (caliperetry: SFT) at standard anatomical sites using a specialized instrument, a caliper. The examination presents no difficulties in children with any pathology and can be performed regardless of the disease period and severity of the condition. Caliperetry has been shown to be highly informative in critically ill patients. For instance, during children's stay in the ICU, the dynamics of SFT and their sum were negative, regardless of age.

Bioimpedance analysis (determining the percentage ratio of water, muscle, and adipose tissue using a bioimpedance meter) is a non-invasive measurement method based on the differences in the electrical resistance of tissues (adipose, muscle, bone), enabling the analysis of morphological and physiological parameters of the body: body mass index, fat mass, lean (fat-free) body mass, active cell mass, skeletal muscle mass, etc.

Assessment of total body composition is useful for prescribing appropriate medical and dietary interventions and interpreting anthropometry. Unlike the adult patient population, there is limited evidence in pediatrics supporting the impact of body composition on predicting sarcopenia outcomes [64].

It is important to interpret the results of body composition assessment in relation to other patient parameters, such as weight, height, disease severity, mobility, and physical activity, in order to use this information for individualized nutritional recommendations.

Comment: expired air samples are collected sequentially—first on an empty stomach (before carbohydrate substrate administration), and then every 15 minutes for 90 minutes [178].

#Dextrose** or #lactulose** for the breath test must be mixed in 200–300 ml of pure drinking water [177].

The test result is considered positive if there is an increase in hydrogen levels in exhaled air of ≥ 20 ppm (parts per million, ppm) and/or methane levels of ≥ 10 ppm within 90 minutes [178].

- this time period reflects the presence of #dextrose** or #lactulose** in the small intestine in both adults and children [179].

Instrumental diagnostics of complications associated with central venous catheters (CVC)

Comments: ultrasonic duplex scanning of upper extremity vessels (arteries and veins), ultrasonic duplex scanning of lower extremity vessels (arteries and veins) may be adequate for jugular thrombosis, but inadequate for diagnosing subclavian or superior vena cava thrombosis. Nevertheless, this method can be used as a starting point because it is non-invasive and easy to perform. An additional imaging method is magnetic resonance venography (one region) / magnetic resonance angiography (one region), which can serve as a non-invasive alternative to invasive venography for detecting central vessel-associated thrombosis [125].

2.5 Other Procedures

2.5.1 Assessment of Actual Dietary Intake

- The most appropriate approach for analyzing actual nutrition is the 24-hour dietary recall method (assessment of actual nutrition using the 24-hour dietary recall method) including the route of food administration (oral, via tube, or gastrostomy), feeding schedule, qualitative and quantitative composition of food intake, and fluid volume. This method allows for an objective assessment of nutrient and energy intake and, accordingly, the identification of deficiencies if present. The methodology for conducting the actual nutrition assessment is detailed in [66].

- A more informative method for assessing nutrient intake is a 3–7 day food diary, including one weekend or holiday and two weekdays [67].

CGR CLOE 5Level of Clinical Guidance - C (Level of Evidence - 5)

Comment: nutritional information can be obtained from legal representatives/caregivers or medical personnel. Information on nutrition obtained directly from the child can be considered reliable no earlier than the child reaches the age of 10 years [66, 67].

2.5.2 Other diagnostic examinations

The use of other diagnostic methods is dictated by the clinical necessity to assess the etiological factors of protein-energy malnutrition or to perform differential diagnosis with other conditions presenting a similar clinical picture.

Comments: necessary consultations are carried out depending on the clinical situation.

For example:

Comments: eating and feeding disorders (anorexia nervosa, bulimia nervosa, ARFID, and other feeding disorders) and other mental disorders accompanied by protein-energy malnutrition (depressive and anxiety disorders, bipolar affective disorder, etc.) have a significant prevalence in the pediatric population and require timely diagnosis by a psychiatrist and treatment to prevent chronicity, somatic complications, and mortality.

Comments: consultation regarding palliative care may be provided at all stages of managing a patient with PEW: during key therapeutic decision-making, in the event of life-threatening conditions, as well as in the terminal phase of the disease.

2.5.3 Monitoring of patients receiving enteral nutrition

Comments: monitoring is always individual and should include the assessment of:

- general clinical status (therapeutic history taking and symptom review, therapeutic visual examination, therapeutic palpation, therapeutic auscultation);

- functional state of the gastrointestinal tract (stool character, frequency);

- degree of meeting estimated fluid, energy, and protein requirements;

- anthropometric dynamics (body weight measurement, height measurement, head circumference measurement [in children under 2 years of age], mid-upper arm circumference [MUAC], triceps skinfold thickness [TSFT], and, if indicated, body composition [determination of water, muscle, and fat tissue percentage using bioelectrical impedance analysis]). All anthropometric data obtained during the examination are evaluated against Z-score standard deviations;

- general clinical biochemical blood analysis (study of blood albumin level, study of total blood protein level, study of serum transferrin level) and complete blood count;

- assessment of the condition of the feeding tube (stoma) in tube feeding.

2.5.4 Monitoring of patients receiving parenteral nutrition

Comments: it is also recommended to perform regular physical examination (including therapeutic visual examination, therapeutic palpation, therapeutic percussion, therapeutic auscultation [visual examination of the skin and mucous membranes, subcutaneous adipose tissue, assessment of peripheral edema, state of the digestive organs (dyspeptic manifestations, stool character), features of cardiac activity (heart rate measurement, pulse examination, blood pressure measurement on peripheral arteries, auscultation in heart and pericardial pathology]).

Comments: the table in Appendix A3.11 shows the parameters typically used in children with malnutrition who require parenteral nutrition. The scope and frequency of tests may be adjusted depending on the clinical situation [82].

2.5.5 Monitoring of bone mineral metabolism in children receiving parenteral nutrition

Comments: bone fractions of alkaline phosphatase isoenzymes in the blood are examined. The frequency of testing is determined individually, depending on the clinical situation.

Comments: the frequency of the study is determined by the clinical situation and the results of previous examinations (no more than once every 6–12 months).

If abnormalities are detected, the patient is prescribed treatment in accordance with clinical guidelines for osteopenia/osteoporosis, including the possible use of bisphosphonates.

2.5.6 Monitoring of liver function in children receiving parenteral nutrition

Comments: alkaline phosphatase and gamma-glutamyltransferase are the earliest markers of liver function, though not highly specific, whereas a significant increase in bilirubin levels may develop against the background of progressing cholestasis.

Children requiring long-term parenteral nutrition are at high risk for liver disease, most of which is transient and reversible after the cessation of nutrition. However, prolonged parenteral nutrition can lead to more serious consequences: cholestasis, cholelithiasis, fibrosis, and steatosis. The pathogenesis of liver injury during parenteral nutrition remains not fully understood. It is hypothesized to be a multifactorial interaction caused by the underlying disease, infection, and components of parenteral nutrition [143, 144].

Liver function abnormalities are recorded on days 7–14 of parenteral nutrition as an increase in transaminases and bilirubin levels, although histological examination of liver tissue does not confirm pathological changes. These deviations are transient, do not depend on the presence of fat emulsions, and in most cases return to normal after parenteral nutrition is discontinued. Histological changes in hepatic Kupffer cells, presenting as lipid inclusions, occur with prolonged intravenous administration of fat emulsions (more than a month). The role of such fat deposition is not yet sufficiently clear. Cholestatic jaundice, as a complication of total parenteral nutrition, is more common in young children, which is apparently associated with the immaturity of the excretory function of the biliary system. 2 to 3 weeks after stopping parenteral nutrition, cholestatic jaundice disappears, but in complicated cases, it may progress to severe liver failure.

In short bowel syndrome, the lack of enteral nutrition, stimulation of bile secretion, and bile acid recirculation likely play a leading role in the pathophysiology of cholestasis development and the progression of liver failure. Intestinal obstruction, bowel motility disorders, and resection of the ileocecal valve lead to the overgrowth of colonic flora in the small intestine (small intestinal bacterial overgrowth). Dystrophy of the intestinal mucosa is accompanied by the translocation of intestinal microflora into the portal circulation and the damaging effect of lipopolysaccharides from gram-negative flora on the hepatobiliary system. All these factors contribute to the development of cholestasis [145].

Criteria for an unfavorable prognosis regarding hepatic complications include:

- duration of parenteral nutrition exceeding 3 months;

- bilirubin level exceeding 50 µmol/L;

- platelet count below 100 × 10⁹/L;

- prothrombin time exceeding 15 seconds;

- partial thromboplastin time exceeding 40 seconds;

- liver fibrosis [120].

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

Indications for enteral nutritional support in children over one year of age [72].

1. Insufficiency of standard nutrition:

- inability to provide nutrition amounting to 60–80% of individual nutritional requirements for 10 days or more;

- total feeding time of the child exceeds 4–6 hours per day.

2. Wasting and growth retardation:

- inadequate height or weight gain for more than 1 month in children under 2 years of age;

- weight loss or lack of weight gain for more than 3 months in children over 2 years of age;

- weight-for-age, weight-for-height, or BMI-for-age Z-score below -2 SD;

- triceps skinfold thickness below the 5th percentile for age.

3. Diseases accompanied by malnutrition [73].

Including, in accordance with Appendix 5 of the Order of the Russian Ministry of Health No. 330 dated August 5, 2003, "On measures to improve therapeutic nutrition in healthcare institutions of the Russian Federation":

Conditions that may require enteral nutrition (see Table 1 in Section 1.2)

Contraindications to nutritional support:

General:

○ severe hypoxemia (PaO₂ 3 sec, lactate > 3 mmol/L, pH 6 mm Hg).

○ hypercapnia (PaCO₂ > 80 mm Hg).

○ intolerance to nutritional support formulations (extremely rare).

Contraindications to parenteral nutrition:

○ functioning gastrointestinal tract,

○ hyperhydration,

○ consumption coagulopathy,

○ pulmonary edema,

○ decompensated heart failure,

○ amino acid metabolism disorders,

○ coma of unclear etiology,

○ hypertriglyceridemia (> 3 mmol/L).

Contraindications to the administration of fat emulsions:

○ severe hepatic and/or renal failure.

Contraindications for EN:

○ mechanical intestinal obstruction,

○ mesenteric ischemia,

○ ongoing gastrointestinal bleeding,

○ intestinal perforation or anastomotic leakage,

○ high-output small bowel fistula (consider EN via a tube placed distal to the fistula) [74, 75, 76, 77].

Methods of enteral nutrition administration.

Depending on the condition of the gastrointestinal tract and the patient's neurological status, enteral nutrition is administered via the following methods:

1. Sipping (oral intake of liquid nutritional formulas through a straw or in small sips in small portions).

2. Tube feeding (Administration of a ready-to-use EN formula via a nasogastric tube/nasoenteric tube (Placement of a nasogastric tube) or a gastric/jejunal stoma (Gastrostomy/Gastrostomy using video-endoscopic technologies, Jejunostomy)).

Depending on the severity of the condition, the adaptation period ranges from 2–5 days to 2 weeks. During this time, the tolerance to increasing feeding volumes and the adequacy of the products used are evaluated.

The choice of enteral nutrition method generally depends on a number of key criteria:

- duration of EN support,

- integrity and function of the upper gastrointestinal tract,

- risk of aspiration.

In 2010, the ESPGHAN Committee on Nutrition recommended that postpyloric feeding be indicated only in clinical settings where gastroparesis/motility disorders, aspiration, gastric outlet obstruction, or prior gastric surgery preclude gastric feeding, or when early postoperative feeding is planned following major abdominal surgery [73].

The duration of enteral/nutritional support is determined by the physician individually, taking into account therapeutic efficacy, the patient's condition, and their ability to receive nutrition through normal food using natural products [78].

Dietary adjustment and prescription of oral nutritional support in malnourished children:

Dietary correction requires an integrated and individualized approach, including assessment of the patient's condition, nutritional status parameters, actual dietary intake data, and selection of the nutritional support method.

If oral nutritional support is prescribed to a patient receiving a standard diet, its volume should be 10–15% of the recommended energy intake norms (Appendix A3.12.). If necessary, the volume may be adjusted. In cases of severe and moderate malnutrition, hypercatabolism, or malabsorption, the volume of oral nutritional support using specialized enteral formulas is selected individually.

The principles of correcting nutritional deficiency depending on its severity are presented in Appendix A3.13.

3.1 Conservative Treatment

3.1.1 General principles of nutritional support organization for children over one year of age with malnutrition

3.1.1.1 Enteral nutrition

Comment: RCTs have demonstrated positive effects of nutritional support on growth, morbidity rates, complication rates, and a reduction in the need for hospitalizations and their duration.

The formula must not replace a balanced diet or the child's therapeutic diet!

Comment. Placement of a gastric tube (gastric stoma) (Gastrostomy/Gastrostomy using video-endoscopic techniques) is technically simpler and more physiological, as it does not bypass the gastric phase of food transit. However, in cases of high aspiration risk and impaired gastric motility, a jejunal route (postpyloric) (Jejunostomy) is preferred.

Types of tubes are presented in Appendix A3.14.

Comment: for the group of patients who have indications for enteral tube feeding, but it is required for a prolonged period.

Long-term enteral tube feeding via a nasogastric tube is associated with complications such as skin and mucosal irritation, pressure ulcer formation, and perforations; recurrent nasal infections (sinusitis, otitis media) with a high risk of chronicity.

Indications for gastrostomy placement are [37, 38, 73]:

• Presence of dysphagia and high risk of aspiration syndrome during oral feeding;

• Inadequate oral nutrient intake, food refusal;

• Inability to cover 60–80% of the daily energy requirement for 10 days or more;

• Total mealtime exceeding 4–6 hours per day, with the duration of a single feeding exceeding 30 minutes;

• Lack of weight gain or insufficient weight and/or height gain despite an adequately formulated diet and nutritional support:

- more than 1 month in children under 2 years of age;

- for 3 months in children over 2 years of age;

• Negative body weight dynamics by 2 or more Z-scores despite a diet of adequate caloric value, taking into account age, sex, anthropometric parameters, and adequate nutritional support.

The question of discontinuing enteral nutrition via gastrostomy/jejunostomy is decided on an individual basis, taking into account the preservation of oromotor function and the volume of food consumed orally against the background of positive dynamics in nutritional status parameters.

3.1.1.1.1 Calculation of enteral nutrition requirements

The calculation of nutrient and energy requirements for nutritional support is carried out taking into account the patient's basal metabolic rate (basal energy expenditure), to which correction coefficients are added.

The "gold standard" for determining basal energy expenditure is indirect calorimetry. This method allows for the determination of individual energy expenditure, as well as the individual rate of oxidation of proteins, fats, and carbohydrates to support basal metabolism. Calorimetry is indicated in:

o clinical conditions accompanied by a significant change in daily energy requirements (severe burns, polytrauma, prolonged septic condition);

regarding the ineffectiveness of adequately prescribed nutritional support;

regarding the duration of muscle relaxant administration for more than 7 days [85].

If there are no indications or facilities for performing calorimetry, one of the formulas for calculating the child's basal energy expenditure must be used.

In certain cases, calculated parameters do not allow achieving optimal nutritional status parameters, since other factors may also affect energy requirements (Appendix A3.16).

Comment. Overfeeding can worsen the patient's condition. During the disease period, when protein catabolism is observed, the patient is already overloaded with protein metabolites, and additional protein administration will reorient their metabolism and lead to ketosis and anabolism.

3.1.1.1.2 Selection of enteral nutrition formula

Comments. Currently, a wide range of formulas for children requiring nutritional support is available in our arsenal (see the "Terms and Definitions" section).

Polymeric isocaloric enteral formulas intended for use in pediatric practice, adapted to the needs of the child's body, represent the largest group, have universal application, and in most cases are the optimal choice.

Hypercaloric nutritional formulas are the choice in case of increased nutrient requirements (in hypermetabolism) and limited fluid intake due to their ability to provide nutritional correction in a small volume.

Formulas with dietary fiber are prescribed in case of intestinal hypotonia (patients with insufficient physical activity, immobilized patients, etc.), unstable stool patterns, phenomena of intestinal microbiocenosis disturbance, or the risk of dysbiosis.

Semi-elemental (oligomeric) formulas are indicated in case of malabsorption or intolerance to polymeric formulas. Semi-elemental formulas are also effective for certain motor and evacuation disorders, due to their ability to rapidly empty from the stomach and pass through the gastrointestinal tract. They are optimal when used in children with chronic severe malnutrition against the background of evacuation-motor disorders and suppression of the secretory activity of the gastrointestinal tract at the start of diet therapy.

Specialized formulas for enteral nutrition (metabolically targeted formulas) have a modified composition depending on the prevailing pathology.

Modular formulas (protein, fat, vitamin-mineral) are used to enrich the traditional diet or base formulas taking into account individual needs.

For example, using a protein module to increase muscle mass in pediatric patients with cystic fibrosis presenting with protein malnutrition. The use of this product in children receiving targeted therapy avoids additional fat and carbohydrate loads, which can help reduce the risk of overweight and obesity [202, 203].

Comments. Both deficiency, which will not lead to a therapeutic effect and positive dynamics of nutritional status parameters, and excess intake of nutrients and energy are negative. The latter leads to hypermetabolism, the development of overweight, hepatic steatosis, impairs respiratory function, and increases the risk of aspiration.

Patient energy requirements vary significantly depending on the level of physical activity, specific disease characteristics and course, therapy, presence of complications, and other factors, and may sometimes differ substantially from standard guidelines [112]. The specific individual metabolic needs of a patient with nutritional support are determined in accordance with relevant clinical guidelines and may be modified by a decision of the medical commission.

The need for a specialized medical nutrition product, its specific features, and the type of formula are determined on an individualized basis by the medical commission in accordance with the legal regulations of the Russian Federation.

• For patients receiving nutrition via a nasogastric tube / nasoenteric tube / stoma, it is recommended to use an enteral formula as the primary source of nutrition, since this method of nutritional delivery is optimal compared to a regular pureed hospital diet and helps to fully ensure adequate macronutrients and energy [113, 193, 194].

Level of Recommendations - CLevel of Evidence - 3Recommendation Grade C (Level of Evidence 3)

Comments: selection of an enteral nutrition product must be based on an analysis of the patient's nutritional status, age, the specifics and course of the underlying disease, as well as the presence of comorbid pathology and the severity of gastrointestinal symptoms.

Comments: the selection of a combination of enteral nutrition products must be carried out based on nutritional status, age, and the specific course and nature of the underlying disease.

Complications of tube feeding (via nasogastric tube / nasoenteric tube / stoma) and their prevention:

1. MECHANICAL COMPLICATIONS.

1.1. Tube obstruction.

Causes:

• Aggregation and precipitation of enteral formula components.

• Use of viscous nutritional substrates.

• Administration of undissolved or undiluted medications or enteral formula components.

• Inadequate flushing of the tube.

Prevention:

• Use of specialized liquid enteral formulas with optimal osmolarity.

• Flushing the tube with 30–50 ml of sterile water for injections** every 4 hours in patients receiving continuous feeding, and before/after bolus administration.

• Use of alternative routes for drug administration (parenteral).

1.2. Tube migration or displacement.

Causes:

• Inadequate tube fixation.

• Vomiting, coughing, reflex movements of the patient.

• Gastrointestinal motility disorders (delayed gastric emptying, gastroparesis).

Prevention:

• The position of the tube can be verified using ultrasound diagnostics (ultrasound examination of the esophagus, gastric endosonography), radiologically (esophagography, radiography of the stomach and duodenum), if the inserted tube has a weighted tip (oliva) or contains a radiopaque marker, as well as by aspirating gastric contents with a syringe and determining the pH of the aspirate using test strips (duodenal sounding with content analysis) (pH ≤ 4 confirms placement in the stomach). Alternatively, 20–30 ml of air can be injected with a syringe while auscultating over the stomach area. A characteristic "gurgling" sound indicates that the tube is in the stomach [114, 115, 116].

• Fixation of the tube using skin adhesive tapes or special fixation devices.

• Correction of gastroparesis through the use of gastrointestinal motility stimulants.

1.3. Iatrogenic gastrointestinal injuries.

Causes:

• Mechanical trauma to the mucosa (nasopharyngeal pressure ulcer, esophagitis, perforation).

• Prolonged nasogastric intubation without tube replacement.

Prevention:

• Regular tube replacement (at least every 4 weeks for long-term use).

• Use of nasogastric / nasoenteric feeding tubes (thin polyurethane or silicone tubes).

• Consideration of alternative methods (gastro-/jejunostomy if prolonged enteral nutrition > 4 weeks is anticipated).

2. GASTROINTESTINAL COMPLICATIONS.

2.1. Gastrostasis and vomiting.

Causes:

• Delayed gastric emptying (gastroparesis, sepsis, hyperglycemia).

• High volume of single-portion (bolus) feeding.

• Hyperosmolarity of the nutritional formula.

Prevention:

• Assessment of gastric residual volume every 4–6 hours (volume > 200 ml is an indication for adjusting the feeding regimen).

• Switch to continuous infusion via an infusion pump.

• Prescription of gastrointestinal motility stimulants.

2.2. Diarrhea.

Causes:

• High osmolarity of enteral formulas.

• Contamination of enteral nutrition when using open systems.

Prevention:

• Use of iso-osmolar formulas.

• Use of closed sterile feeding systems.

2.3. Constipation.

Causes:

• Dietary fiber deficiency in the diet.

• Inadequate fluid intake.

• Patient hypomobility.

Prevention:

• Administration of ≥ 30 ml/kg/day of fluid.

• Use of enteral formulas containing dietary fiber.

• Correction of physical inactivity (repositioning the patient, therapeutic exercise for colon diseases).

2.4. Refeeding syndrome (see section 3.3.1).

3. INFECTIOUS COMPLICATIONS.

3.1. Contamination of enteral nutrition.

Causes:

• Use of open systems for > 4–6 hours.

• Non-compliance with sanitary and hygienic standards during formula preparation.

Prevention:

• Compliance with sanitary standards when handling enteral formulas.

• Use of closed systems with replacement every 24 hours.

• Hand hygiene compliance during tube manipulations.

3.2. Gastrostomy/Jejunostomy Site Infections.

Causes:

• Bacterial colonization due to failure to follow asepsis rules.

• Mechanical trauma to the skin around the stoma.

Prevention:

• Antiseptic skin care around the gastrostomy twice a day.

• Use of barrier dressings in the presence of exudation.

• Antibiotic therapy if inflammation develops.

3.1.1.1.4 Monitoring of the patient with malnutrition receiving enteral nutrition

See Section 2.5.3 and Appendix A3.10.

3.1.1.2 Parenteral nutrition

Parenteral nutrition (PN) refers to infusion therapy aimed at supplying water, macronutrients, and micronutrients according to the body's requirements. Total, partial, and supplemental PN are distinguished.

Partial or mixed PN is the parenteral administration of nutrients when enteral nutrition is limited.

Supplemental PN is the administration of specific nutrients when their requirement increases (e.g., supplemental amino acids when activation of reparative processes is needed).

Depending on the type of venous access, 2 types of parenteral nutrition are distinguished:

– peripheral PN (no more than 2 weeks using 10% dextrose** solutions);

– central PN (when peripheral access is limited and PN duration exceeds 2 weeks using dextrose** solutions greater than 10%).

Initiation of PN involves prior correction of water-electrolyte and acid-base disturbances.

The volume of infusion therapy (IT) consists of 3 components: physiological requirement (PR), fluid replacement for dehydration (FRD), and ongoing pathological fluid losses (OPFL). The formula below is used for children with a body weight greater than 10 kg: V_inf = PR + FRD + OPFL.

The physiological fluid requirement in children depending on body weight is determined as follows [118, 119, 120, 121].

- up to 10 kg: 100 mL/kg/day;

- 10–20 kg: 1000 mL + 50 mL for each kg of body weight over 10 kg;

- more than 20 kg: 1500 mL + 25 mL for each kg of body weight over 20 kg.

The physiological requirement is replenished by continuous infusion throughout the day. The volume of infusion therapy for dehydration correction (FRD) depends on the degree of dehydration, determined by clinical and laboratory parameters (Appendix A3.17). For the volume of infusion therapy depending on the degree of dehydration, see Appendix A3.18.

In case of stable hemodynamics, the calculated infusion volume for exicosis correction must be divided into two equal parts, with the first part administered over 8 hours and the second over 16 hours.

The volume of infusion therapy for ongoing pathological losses (OPFL) is calculated as follows:

– for each degree of body temperature above 37⁰C for at least 8 hours — 10 mL/kg;

>– for every 20 breaths above the age-related norm — 15 mL/kg;

– for vomiting — 20 mL/kg (1 L of gastric juice contains 50–100 mmol of sodium, 10–20 mmol of potassium, and 100 mmol of chlorine);

– for frequent stools — 20–30 mL/kg after each bowel movement (approximately 40 mmol of sodium, potassium, and chlorine per liter of intestinal losses);

– for stage 2 intestinal paresis — 20 mL/kg, stage 3 — 40 mL/kg;

Ongoing pathological losses are compensated for immediately upon their recording.

The volume of infusion therapy must be restricted in conditions such as cerebral edema, heart failure, edema, acute renal failure, and respiratory failure caused by acute lung injury, respiratory distress syndrome, or pneumonia.

IT restrictions can be calculated as 2/3 to 3/4 of the PR or insensible perspiration losses — 300–400 mL/m² plus the previous day's urine output, depending on the patient's condition severity [122, 123].

Comments: such situations may occur, for example, in the following conditions:

o Burns.

o Multiple organ failure.

o Malabsorption.

o Short bowel syndrome.

o Chronic refractory diarrhea.

o Congenital small intestinal malabsorption syndromes, such as congenital chloride diarrhea, tufting enteropathy, or microvillus inclusion disease.

o Pseudo-obstruction.

o Severe malnutrition with hypoproteinemia and intestinal edema.

o Non-functional gastrointestinal tract.

o Paralytic ileus.

o Small bowel ischemia.

o Necrotizing enterocolitis.

o Gastrointestinal surgeries.

o Gastroschisis, omphalocele, gastrointestinal atresias (parenteral nutrition is indicated until the enteral route becomes functional and accessible).

It is necessary to thoroughly assess the nutritional status (see Section 2), establish nutritional goals, and determine the expected duration of PN. This process is dynamic: adjustments are made under the control of clinical, laboratory, and, if necessary, instrumental parameters.

Comments: conducting PN via a peripheral intravenous catheter can be done for a short period of time. The osmolarity of PN solutions when administered into a peripheral vein must be maintained below 980 mOsm/L.

General-purpose infusion pumps are used when possible and necessary.

It is preferable, whenever possible, to use a centrally inserted central venous catheter (Broviac type).

Port systems are rarely used, per the physician's decision.

The daily requirement for electrolytes and minerals depending on age is presented in Appendix A3.19 [118, 121].

Na⁺ deficit (mmol) = (desired Na⁺ — actual Na⁺ ) × BW (kg) × K,

where K is the extracellular fluid coefficient for premature infants — 0.45, newborns — 0.4, infants — 0.3, young children — 0.25, school-age children — 0.2, averaging — 0.3, for the purpose of correcting hyponatremia [121, 127, 128].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comments: 1 mL of 10% sodium chloride** solution contains 1.7 mmol of sodium.

Infusion rate: the optimal increase in serum sodium levels in hyponatremia should not exceed 0.5 mmol/L/h (preferably no more than 6–8 mmol/day), given the risk of osmotic demyelination syndrome. Sodium is the main extracellular cation, modulating intravascular and interstitial fluid volume. Severe hyponatremia is associated with cerebral edema, seizures, loss of consciousness, and coma. The most common causes of hyponatremia are excessive sodium loss in surgical gastrointestinal disorders (drains, fistulas) and non-surgical conditions (gastroenteritis), as well as renal diseases.

Hypernatremia (Na > 145 mmol/L) is overwhelmingly a consequence of "iatrogenesis," including inadequate correction of pathological and perspiratory losses, physiological requirements, excessive administration of sodium and/or sodium-containing drugs. Therapeutic options are determined by the etiological factor. Rapid correction of hypernatremia may be accompanied by cerebral edema, seizure activity, and other neurological complications; therefore, the rate of sodium reduction should not exceed 0.5 mmol/L/h (preferably no more than 6–8 mmol/day), especially if the duration of hypernatremia exceeds 24–48 hours [127].

Correction of hypokalemia must be performed gradually, taking into account renal and cardiac function. Patients with nutritional insufficiency exhibit a decreased ability to incorporate potassium into metabolic processes due to low energy reserves, protein deficiency, and impaired protein synthesis. Therefore, in the early stages of PN, excessively rapid correction of hypokalemia should be avoided, as it may be accompanied by hyperkalemia and cardiac arrhythmias.

Comments: recently, due to its complexity, the determination of intracellular potassium is rarely used.

The recommended potassium concentration in the infusion medium is no more than 0.75% (1 ml of 7.5% potassium chloride contains 1 mmol of potassium).

Potassium is the primary intracellular cation. There is a direct link between negative energy balance and hypokalemia. Clinical signs typically appear when serum potassium drops below 2.5 mmol/l: muscle hypotonia, cramps, intestinal paresis. Neurological and mental disorders are observed — skin numbness, paresthesias, irritability, apathy, lethargy. The most dangerous complications are increased myocardial excitability (heart rhythm disorders in the form of ventricular extrasystole, ventricular fibrillation) and metabolic alkalosis. The most significant causes of hypokalemia include potassium losses through the gastrointestinal tract: gastroenteritis, intestinal obstruction, intestinal paresis, peritoneal drains, and less commonly, prolonged exfusion of pleural fluid and cerebrospinal fluid [127].

Comment: 1 ml of 25% magnesium sulfate** solution contains 1 mmol of magnesium (for magnesium requirements, see Appendix A3.19).

Comments: the enteral route is the most preferred way of administering iron supplements; if this method is not tolerated, iron preparations are administered parenterally. It is important to monitor parameters reflecting iron metabolism: hemoglobin level, ferritin, transferrin saturation, mean corpuscular hemoglobin, and mean corpuscular volume to avoid iron overload (see section "Monitoring Parameters of Parenteral Nutrition") [129] (see subsection "Monitoring Parameters of Parenteral Nutrition").

One of the most critical tasks of parenteral nutrition is to adequately meet the body's energy requirements in a child (basal metabolic rate, physical activity, growth, malnutrition, prior nutritional deficiency). On the one hand, excessive energy load may be accompanied by hyperglycemia, excessive fat deposition, fatty liver disease, parenteral nutrition-associated liver disease [130]; on the other hand, insufficient energy supply is associated with malnutrition, hypostasis, and immune incompetence.

In the initial period of parenteral nutrition, rapid correction of protein catabolism is impossible; therefore, energy deficit correction should be carried out slowly, taking into account the low basal metabolic rate and prior nutritional deficiency [129]. Excessive administration of nitrogen (amino acids for parenteral use (crystalline amino acids)) can lead to hyperammonemia and/or metabolic acidosis if the renal clearance capacity for hydrogen ions and phosphate ions is exceeded.

Comments: when correcting protein deficit, it is important to ensure the simultaneous intake of both nitrogen and calories in the correct ratio.

Nutrient balance.

During parenteral nutrition, it is necessary to maintain the correct proportions between macronutrients, electrolytes, vitamins, and trace elements. Imbalances can be corrected by administering nutrients in the following proportions: 200 to 250 kcal per 1 g of nitrogen, 1.8 mmol of calcium, 2.9 mmol of phosphorus, 1.0 mmol of magnesium, 10 mmol of potassium, 7 mmol of sodium and chloride, and 1.2 mg of zinc.

Daily energy requirements determined based on age and the phase of the disease are presented in Appendix A3.21; currently, the determining factor is not the day from the start of parenteral nutrition, but the patient's condition and the phase of the disease.

The acute phase refers to the condition of a patient requiring intensive care (including sedation (anaesthesiological support (including early postoperative management)), mechanical ventilation, vasopressor support, and infusion therapy (continuous intravenous drug administration)).

The stabilization phase is characterized by patient stabilization and the cessation of life-support functions.

The recovery phase means the patient requires rehabilitative care. In cases where parenteral nutrition is supplementary or partial, the full energy and nutrient load is achieved by the end of days 3–4 [118, 131].

It must be emphasized that infants in their first year of life with nutritional failure may require about 150–170 kcal/kg/day to meet their growth requirements.

Below are the energy sources necessary to provide full parenteral support for the patient.

Maintaining a stable glycemic level requires, on the one hand, careful monitoring of the glycemic profile and, on the other hand, continuous infusion, which is explained by the body's limited carbohydrate reserves. Therefore, during initial parenteral nutrition, a continuous dextrose** infusion rate is established, which should not be lower than the rate of glucose production.

Comments: glycemic level is one of the most important indicators of carbohydrate metabolism in the body. In addition to exogenous glucose intake, endogenous glucose production occurs in humans.

The basal rate of endogenous glucose production (EGP) ranges from 2 mg/kg/min (2.9 g/kg/day) in adults to 8 mg/kg/min (11.5 g/kg/day) in preterm infants, meaning that the maximum EGP level is observed in the postnatal period, followed by a decrease proportional to age.

It should be remembered that in critically ill children, EGP decreases, which necessitates a reduction in the rate of dextrose** administration [131, 133].

During parenteral nutrition, the rate of dextrose** administration should not exceed the maximum glucose oxidation rate (GOR), which varies significantly depending on the child's age and condition (Appendix A3.22).

Comments: Lipid emulsions for parenteral nutrition** are metabolized similarly to natural chylomicrons during enteral nutrition. In the capillaries of adipose and muscle tissue, apoproteins on the surface of chylomicrons activate endothelial lipoprotein lipase, which hydrolyzes 90% of the triglycerides contained in chylomicrons into fatty acids and glycerol, which are taken up by adipocytes and muscle cells or utilized for energy production.

Types of lipid emulsions for parenteral nutrition** are presented in Appendix A3.23.

During long-term in-hospital PN, lipid emulsions for parenteral nutrition** are infused around the clock; during cyclic PN (e.g., at home), the infusion duration of lipid emulsions for parenteral nutrition** is determined by the duration of carbohydrate and amino acid infusion.

PN is associated with the development of cholestatic hepatitis and liver fibrosis; therefore, long-term PN using pure soybean oil-based lipid emulsions for parenteral nutrition** should be avoided. The use of composite emulsions administered via light-protected infusion systems is recommended.

It is important to consider that young children have decreased lipoprotein lipase activity, which can lead to hyperlipidemia. However, it should be noted that administration of heparin sodium** leads to an increase in free fatty acid blood concentrations, exceeding the infant's capacity to bind lipolysis products and reducing the binding ability of endothelial lipoprotein lipases to the endothelium [135]. Furthermore, the complex of heparin sodium** and calcium (ATC code B01AB01 - heparin calcium) can destabilize the lipid emulsion, causing an increase in chylomicron size, which negatively affects microcirculatory perfusion. Therefore, heparin sodium** should not be used routinely during pediatric PN [134].

Comments: ESPEN recommends maintaining triglyceride levels during PN at or below 3 mmol/L for preterm infants and neonates, and 4.5 mmol/L for older age groups. Lipid emulsions for parenteral nutrition** are prescribed with caution in hyperbilirubinemia (depression of bilirubin glucuronidation, development of cholestatic hepatitis, liver fibrosis), respiratory failure (worsening of alveolar-capillary diffusion with subsequent reduction in pO_2, worsening of pulmonary hypertension, especially when using pure soybean oil-based lipid emulsions for parenteral nutrition**), and sepsis [118, 134].

Amino acids for parenteral administration (crystalline amino acid solutions) are important nitrogen sources used in PN. Most amino acids for parenteral nutrition** currently in use contain an amino acid profile corresponding to that of breastfed infant plasma.

Comment: to maximize the anabolic effect of PN, the energy (kcal) to nitrogen (g) ratio should be 250–300:1, or 30–40 kcal per 1 g of amino acids, ensuring their adequate utilization.

It is important to note that 6.25 g of protein contains 1 g of nitrogen. The caloric value of protein is 4 kcal/g, but when calculating total PN caloric intake, only non-protein calories (i.e., dextrose** and lipid emulsions for parenteral administration**) are taken into account.

(active ingredient: N(2)-L-alanyl-L-glutamine), vitamins, Amino acids for parenteral nutrition + Other drugs [Dextrose + Lipid emulsions for parenteral nutrition + Minerals]**

Comments: Administration of amino acids for parenteral nutrition** (active ingredient: N(2)-L-alanyl-L-glutamine) during parenteral nutrition reduces bacterial translocation by preventing mucosal atrophy and stimulating gut-associated lymphoid tissue, normalizes secretory immunoglobulin A production, and improves endocrine, metabolic, and barrier functions, the integrity of which plays a key role in preventing multiple organ dysfunction syndrome caused by the translocation of bacteria and toxins into the systemic circulation in critical illness.

A reduction in mortality, hospital length of stay, and treatment costs has been demonstrated.

Intravenous administration of amino acids for parenteral nutrition** (active ingredient: N(2)-L-alanyl-L-glutamine) corrects glutamine deficiency in patients with GI disorders and critically ill patients.

Comments: They are administered in accordance with the package inserts in cases of prolonged (more than 7–14 days) PN [121, 138].

Comments: Advantages of "three-in-one" technology over separate infusions of amino acids for parenteral administration**, lipid emulsions for parenteral nutrition**, and dextrose** include:

– high technological efficiency, convenience, and ease of use. When using "three-in-one" technology, there is no need to calculate the dose and infusion rate of individual components (amino acids, lipids, and glucose);

– optimally balanced composition. There is no need to specially calculate the ratio of administered components (amino acids to energy, and glucose to lipids).

– An example of nutritional calculation is presented in Appendix A3.25.

Presented in section 2.5.4 and Appendix A3.11.

Long-term total PN is associated with the development of a broad spectrum of complications varying in severity. Complications of PN are due to the following factors [125]:

– presence of a CVC/implantable port system***;

– instability of PN admixtures;

– drug-drug interactions between co-administered medications;

– metabolic disorders.

Infectious Complications

Infection is one of the most common CVC-related complications and is associated with reduced survival rates in intensive care units (ICUs) [125].

• For long-term parenteral nutrition in children in a hospital or home setting, it is recommended to use a CVC or port system***; when using double- or triple-lumen catheters, one port must be dedicated to parenteral nutrition, one for blood sampling, and one for infusion therapy [139].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comments: it is preferable to use a centrally inserted central venous catheter (such as a Broviac catheter).

Port systems*** are rarely used and only upon a physician's decision.

When placing a CVC in the superior vena cava system, the tip of the catheter should be located in the superior vena cava; when catheterizing the inferior vena cava, it should be above the origin of the renal vessels.

The nutrition port must not be used for blood sampling.

Comments: compliance with asepsis and antisepsis rules is the basis for the prevention of infectious complications. As is well known, the "horizontal" transmission route of infections is primary in the development of purulent-septic complications.

Comment: monitoring for CVC-associated infection must be carried out regularly, and prompt measures must be taken at the slightest suspicion. A patient with the listed signs is at risk.

Microbiological diagnosis of catheter-related bloodstream infection is described in Section 2.3.

CVC Occlusion

CVC occlusion may be caused by impaired patency of either the catheter itself (thrombosis, precipitation of the parenteral nutrition solution) or the vein (thrombosis or fibrin sheaths). In addition, occlusion can occur due to causes external to the CVC (the catheter tip abuts the vein wall, changes in the patient's posture leading to compression of the CVC between the clavicle and the first rib [pinch-off syndrome]).

Comments: if the CVC is not in use, it must be flushed with a heparin sodium** solution.

• In early-stage CVC thrombosis (after the first unsuccessful attempt at blood withdrawal from the catheter), it is recommended to perform catheter thrombolysis with agents including tissue plasminogen activator (#alteplase** (0.5–2 mg instilled into the lumen of the catheter, maximum twice with a dwell time from 30 to 120 min [up to a maximum of 240 min])) to resolve the thrombosis [125].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comments: Pinch-off syndrome is characterized by: localized pain syndrome worsening with movement, erratic blood flow from the catheter, high infusion pressure varying depending on the patient's position.

Central Venous Thrombosis and Pulmonary Embolism

Central venous thrombosis (CVT) and pulmonary embolism (PE) are potentially fatal complications. The likelihood of developing CVT increases significantly during long-term parenteral nutrition lasting several weeks. Clinical symptoms of CVT in the superior vena cava system (the most frequently used venous access) are characterized by facial edema, collateral venous hypertension, and/or pain during intravenous injections.

Diagnosis of CVT is based on echocardiography, Doppler studies, computed tomography, and/or angiography.

Pulmonary embolism is characterized by chest pain, dyspnea, hemoptysis, syncope, tachypnea, tachycardia, diaphoresis, and fever. "Minor thrombosis" may be asymptomatic or present with vague symptoms such as fatigue.

CVT and PE may be associated with recurrent CVC infections, repeated CVC position changes, proximal tip placement of the CVC in the superior vena cava or internal jugular vein, frequent blood sampling, administration of concentrated dextrose** solutions and medications; furthermore, these complications can be idiopathic.

Comments: if these symptoms are detected, it is necessary to promptly assess the situation and take appropriate measures.

Laboratory diagnosis of CVT is described in Section 2.3, instrumental diagnostics in Section 2.4

• In the case of diagnosed thrombotic complications, it is recommended to remove the CVC, especially if it is infected. Vitamin K antagonists or "heparin group" drugs can reduce the risk of blood clots and may be selectively prescribed to patients on long-term parenteral nutrition at an increased risk of thromboembolism to reduce that risk [125, 141].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comments: acute symptomatic thrombosis is best treated with ATC group B01AD drugs "Enzymes" (thrombolytic agents), including tissue plasminogen activator (#alteplase**), but the use of antithrombotic agents (anticoagulants) remains the most common therapeutic approach.

Extravasation or Catheter Damage

Extravasation of the CVC is caused by both accidental and intentional traction.

Comments: the lifespan of long-term CVCs/port systems*** (including implantable ones) is limited. Bleeding from catheter damage or an insecure connection is a life-threatening condition.

To reduce the frequency of this complication, it is advisable to use infusion sets equipped with a Luer lock system (single-use three-piece sterile catheter-type injection syringe, single-use three-piece or two-piece sterile injection syringes).

Comments: an important property of parenteral nutrition preparations is stability, meaning the ability of the mixture or solution to maintain the same physicochemical properties after a certain period of time as at the beginning of their use:

- stable lipid particle size;

- absence of precipitation of insoluble complexes formed from mixture components;

- availability of all components;

- absence of chemical reactions between components.

- According to the manufacturers' recommendations, the administration of monocomponent preparations and "3-in-1" parenteral nutrition (PN) mixtures is permitted. In the first case, separate administration of carbohydrates with the addition of electrolytes, amino acids, and lipids is performed. The "3-in-1" mixture contains all the listed components, including lipids, in a single container. Up to 100 chemical substances present in the mixture represent a huge potential for interaction. "3-in-1" mixtures are administered via a single line, and the stability of the emulsion parameters is confirmed by the manufacturer. Manufacturers' studies on the compatibility of "2-in-1" components generally do not guarantee the stability of the intravenous fat emulsion in the final solution. The intravenous fat emulsion is infused "separately," but in practice, this usually means through the same infusion line via a Y-connector, which does not ensure guaranteed stability of the administered components; therefore, terminal filters should be used during PN [134,142].

- The stability of the "all-in-one" system involves several complex processes of chemical and physical interactions. Therefore, it is unsafe to mix all components in the quantities prescribed by physicians; consequently, it is recommended to prepare "all-in-one" mixtures in accordance with proven guidelines regarding the types and amounts of macro- and micronutrients under strictly controlled conditions. Visual inspection of the mixture for aggregation, separation, and disintegration of the emulsion is required before and during administration.

Metabolic bone disease in adults as a complication of long-term parenteral nutrition is characterized by a decrease in bone mineral density (BMD), osteoporosis, and pathological fractures. Currently, few papers have been published on the development of such complications in children [130]. Decreased bone mineral density is a multifactorial condition caused by both the underlying disease and PN-associated causes: excess vitamin D, phosphorus, nitrogen, amino acids, calcium metabolism disorders, energy imbalance, and aluminum contamination of intravenous solutions.

Studies for monitoring bone mineral metabolism are presented in Section 2.5.5.

Liver function monitoring, prevention, and treatment of cholestasis in children with intestinal failure receiving PN

Parameters for monitoring liver function in children with intestinal failure receiving PN are presented in Section 2.5.6.

– early initiation of cyclic PN;

– if signs of cholestasis appear, including an increase in aminotransferase, alkaline phosphatase, or bilirubin levels — therapy for cholestasis with #ursodeoxycholic acid** (starting dose of 10 mg/kg/day, then, if necessary, the dose can be increased within the range of 10-15 mg/kg/day) [195];

– timely resolution of the possibility of liver transplantation in children with an unfavorable prognosis [125].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comments: balanced PN allows for adequately providing the child's body with amino acids, carbohydrates, fats, and energy necessary to maintain a baseline energy level and correct prior nutritional deficiency. Long-term parenteral nutrition is not a full replacement for enteral nutrition and is associated with complications varying in severity from transient mild ones to severe ones requiring surgical intervention. Knowledge and practical application of modern recommendations will help successfully overcome the problems associated with long-term parenteral nutrition.

Comment: a non-absorbable drug (ATC code A07AA11), #rifaximin is the most studied drug for the treatment of SIBO in adults [197], whereas its use in children has been insufficiently studied.

Comments: when preparing aqueous solutions for parenteral administration, general recommendations must be followed:

- solution mixtures must be used freshly prepared only;

- the more complex the composition of the drug system, the greater the likelihood of interaction between medicinal substances;

- drugs should not be added to blood products, plasma, amino acid solutions for parenteral nutrition**, intravenous fat emulsions**, or unstable solutions such as mannitol** and sodium bicarbonate** (they easily form suspensions when mixed with other medicinal substances);

- amino acid solutions for parenteral nutrition** and intravenous fat emulsions** must not be administered with dextrose** solutions, as toxic products may form;

- dextrose** solutions with a concentration of more than 5% used as solvents may reduce the activity of many medicinal substances;

- destruction of medicinal substances can occur upon interaction with ethanol** and alkalis, which may remain as traces on sterile needles, syringes, and instruments.

Laboratory diagnostics of PN complications associated with water and sodium overload are presented in Section 2.3.

Comments: cyclic PN exerts a protective effect against intestinal failure-associated liver disease and also improves quality of life by increasing infusion-free time during daylight hours.

The transition to cyclic nutrition should be initiated during the hospital stay so that its tolerance/safety can be confirmed before discharge home.

In young children (< 2 years old), abrupt cessation of PN infusion can cause hypoglycemia; in older children, the risk of hypoglycemia is much lower. The cycle time is gradually shortened until the desired/tolerated infusion duration target is reached.

The most common adverse events associated with cyclic PN are hyperglycemia and respiratory distress due to increased rates of dextrose** and fluid infusion; abrupt cessation of infusion can also provoke hypoglycemia. To prevent hypo/hyperglycemia, the infusion rate can be gradually increased over the first 1–2 hours and decreased over the last 1–2 hours of infusion when administering cyclic PN; it is convenient to use an infusion pump (e.g., syringe pump / general-purpose infusion pump, volumetric infusion pump) that allows for the gradual adjustment of the infusion rate. The infusion rate of dextrose**, intravenous fat emulsions**, and solutions affecting the water-electrolyte balance (serving as a potassium source) should also be taken into account when calculating the final infusion rate (see sections "Carbohydrates" and "Lipids").

Comments: Mixed nutrition can be prescribed to patients after abdominal surgery when the patient's condition allows them to partially tolerate enteral nutrition and maintain normal glycemia, while parenteral nutrition is used to fully meet the patient's needs for major nutrients, energy, and micronutrients. As soon as a small amount of nutrition is tolerated, its volume should be increased.

PN should be reduced proportionally or slightly more than the increase in EN.

If adding EN to PN fails, try again, but more slowly.

In children with severe intestinal damage, a very slow increase in enteral nutrition may be required (up to 1 ml/kg/24 h).

3.2 Surgical Treatment

Performed as needed, for example, in the presence of gastroesophageal reflux disease and complications, according to the relevant clinical guidelines [146].

3.3 Other Treatment

3.3.1 Refeeding syndrome

Refeeding syndrome (RFS) is a potentially fatal shift in fluid balance, electrolyte deficiencies (hypophosphatemia, hypokalemia, hypomagnesemia), and thiamine deficiency in malnourished patients occurring upon the resumption of feeding [147, 148, 149].

During malnutrition or starvation, catabolic processes predominate in the body, depleting carbohydrate stores (mainly glycogen in the liver and muscles), as well as fats and proteins [150]. During starvation, serum phosphorus levels decrease due to increased renal excretion and reduced intestinal absorption. In addition, an imbalance of intracellular phosphorus occurs when the body breaks down muscle tissue to provide energy through ATP consumption [151, 152, 153].

Due to the resumption of feeding, especially with a sharp increase in carbohydrate intake, anabolic processes that require increased use of energy and nutrients sharply start [154], and insulin levels rise, promoting the entry of glucose into cells and its metabolism (including the pentose phosphate cycle), which ultimately leads to rapid shifts in electrolyte and fluid balance [155]. Potassium, magnesium, and phosphorus enter the cell, thereby reducing the levels of these electrolytes in the blood. The resulting electrolyte and fluid imbalance can cause various symptoms and complications [156]. Also, due to impaired hormonal and metabolic balance, the acid-base state in the body may change (metabolic alkalosis).

The clinical manifestation of the syndrome is organ dysfunction: acute heart failure, acute renal failure, acute liver failure, arrhythmias, cardiogenic pulmonary edema, cerebral edema, polyneuropathy, thrombocytopenia, disseminated intravascular coagulation (DIC).

A factor provoking RFS in chronically starving patients can be any type of nutrition: oral, enteral, and parenteral.

Symptoms of severe RFS are presented in Appendix A3.26.

ASPEN consensus criteria for identifying pediatric patients at risk for refeeding syndrome are in Appendix A3.27.

Comments. In patients with prolonged starvation, a significant decrease in serum potassium, phosphorus, and magnesium levels is often noted shortly after the initiation of enteral or parenteral nutrition support [158].

Comments. Vital signs should be monitored every 4 hours during the first 24 hours after the initiation of treatment in individuals at risk. Cardiorespiratory monitoring is performed in unstable patients or patients with severe disorders based on established standards of care; the following are also indicated:

daily body weight assessment and diuresis control,

assessment of energy requirements in orally fed patients,

daily assessment of the patient's nutritional status for the first few days until stabilization (e.g., no need for electrolyte-altering solutions (sodium- and potassium-containing) for 2 days) [27, 148].

Comments: the energy value of intravenous dextrose** solutions and medications administered with dextrose** within the limits specified above should be taken into account and/or prescribed with caution to patients with moderate and high risk of RS if the patient has already been receiving intravenous dextrose** for several days and/or dextrose**-based medications with stable blood electrolytes and no symptoms; the nutritional energy load may be reintroduced at doses increased compared to those specified above.

Comment: recommendations may be modified depending on the opinion of the practicing physician and the clinical picture, and nutritional support may be discontinued if electrolyte levels drop sharply and/or are extremely low and life-threatening.

Comment: in accordance with ESPEN (European Society for Clinical Nutrition and Metabolism) guidelines, the correction of hypophosphatemia is carried out gradually, taking into account neurological status and renal function.

There are no registered drugs for phosphorus replenishment in the Russian Federation; therefore, in clinical practice, the only intravenous drug containing phosphorus, #phosphocreatine, is used for vital indications. The recommendation is based on the published case report of a 17-year-old child.

Thorough monitoring of phosphatemia and phosphaturia is mandatory in patients receiving PN and aims to limit phosphaturia.

Comments: once the patient's body weight reaches that of an adult, switch to the recommendations for prescribing multivitamins at the adult dose [148].

3.3.2 Systemic antibacterial drugs for suspected small intestinal bacterial overgrowth (SIBO)

Comments: antibacterial therapy is the preferred strategy for eradicating small intestinal bacterial overgrowth (SIBO). Studies on the efficacy of systemic antibacterial drugs and gut antimicrobials in SIBO vary in patient cohorts, SIBO diagnostic methods, dosage, and treatment duration. Treatment efficacy is determined by the clinical picture. However, empirical prescription of systemic antibacterial drugs and gut antimicrobials to patients with suspected SIBO without a confirmed diagnosis is unjustified, as it exposes them to an unjustified risk of developing antibiotic resistance, antibiotic-associated diarrhea, and C. difficile-associated disease.

3.3.3 Pain management

Pain management in children with PEM is carried out as needed, in accordance with the clinical situation.

3.3.4 Specific features of malnutrition treatment in children with neurological disorders

More details on the treatment of nutritional deficiency in children with neurological pathology are presented in Appendix A3.1.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

The timing, severity, and duration of nutrient deficiencies in childhood affect brain development with varying degrees of long-term consequences. Children may experience delays in motor and cognitive development, behavioral and communication problems. Over time, these can worsen and lead to irreversible impairments if left untreated. The World Health Organization (WHO) recommends incorporating cognitive, emotional, and motor stimulation activities into the rehabilitation program for children with nutritional deficiency [161]. Recently, physical activity appears to be an earlier indicator of successful rehabilitation than weight gain [162, 163].

Physical rehabilitation of malnourished children is of paramount importance to achieve the goal of reducing the number of musculoskeletal and developmental impairments resulting from malnutrition.

• Children with nutritional deficiency are recommended rehabilitation aimed at stimulating gross and fine motor skills, psychosocial skills, and speech, both in an inpatient rehabilitation setting and on an outpatient basis in order to achieve the child's maximum possible development (Medical physical culture for endocrine gland diseases and/or Individual medical physical culture session for endocrine gland diseases and/or Group medical physical culture session for endocrine gland diseases and/or Medical physical culture with biofeedback for endocrine gland diseases) [164, 165].

GoR CLoE 5Grade of Recommendation - C (Level of Evidence - 5)

Comments: are carried out according to the child's capabilities and abilities, as well as in accordance with the underlying disease.

Comments:

Comments: providing services directly to children, including a parental skills development component, is considered a more effective strategy than merely providing information [167].

5. Prevention and Dispensary Observation

5.1 Prevention

The basis for the prevention of malnutrition in children is the awareness of medical staff about the problem and its negative impact on clinical outcomes. The 2023 WHO guideline on the prevention and management of wasting in infants and children under 5 years of age recommends screening all infants and children under 5 admitted to a healthcare facility to ensure immediate care for those with dangerous symptoms of malnutrition. In addition, it emphasizes that nutritional assessment is a vital aspect of the initial evaluation to ensure that malnourished children receive prompt and appropriate dietary interventions [168]. ESPGHAN Special Interest Group on Clinical Nutrition experts believe that nutritional risk screening should be part of primary healthcare for all children admitted to the hospital, to raise medical staff awareness of the need to assess nutritional status and the risk of nutritional deficiency, and to identify children who need further evaluation by a clinical nutritionist. In addition to history taking, all inpatient and outpatient children should routinely undergo weight and height measurements, as well as the calculation of standard deviation scores (Z-scores for weight-for-age, height-for-age, BMI/weight/height) and interpretation using appropriate growth charts in light of previous measurements and the clinical picture. This will provide information on the child's current nutritional status. In children where weight or height measurement is not possible, alternative parameters (MUAC, segment lengths) should be used, which should be supplemented by body composition measurements, including skinfold thickness. Sick children at risk of malnutrition should have the opportunity to be examined by a clinical nutritionist in the hospital and receive appropriate nutritional support.

5.2 Dispensary monitoring

Patients with nutritional deficiency require regular dynamic monitoring (see sections 2 and 3).

Dispanserization (active clinical follow-up) is carried out in accordance with the underlying disease.

5.3 Vaccination

Vaccination in any degree of malnutrition is not contraindicated, which is confirmed by numerous studies conducted around the world.

Providing supplementary nutrition to pregnant women in food-insecure settings can improve infant immune development and vaccine responses [169].

It is reported that malnourished children have lower antibody responses to vaccination against hepatitis B, measles, polio (oral), pertussis, Salmonella Typhi, and tetanus. In addition, malnourished children exhibit less pronounced skin test responses to tuberculin following BCG vaccination [170].

6. Organization of Medical Care

Children with nutritional deficiency, depending on necessity, may be provided with any type, conditions, and form of medical care stipulated by the legislation of the Russian Federation.

6.1 Indications for hospital admission:

6.1.1 Indications for elective hospitalization

- provision of diagnosis and treatment requiring round-the-clock medical supervision;

- a condition requiring active treatment and round-the-clock medical supervision;

- lack of the possibility of providing treatment in outpatient and day-care settings;

- the need for various types of expert evaluations or examinations in a medical organization when they cannot be performed on an outpatient basis, requiring dynamic monitoring, etc.;

6.1.2 Indications for urgent/emergency hospitalization

- life-threatening conditions requiring round-the-clock medical monitoring and special types of examination and treatment.

6.2 Indications for Discharge from the Inpatient Facility

1) absence of a threat to the patient's life;

2) absence of a threat of complications requiring urgent treatment;

3) stabilization of the patient's condition and main clinical and laboratory parameters of the pathological process regarding the underlying disease;

4) absence of the need for continuous medical and round-the-clock observation for the underlying disease;

5) the need to transfer the patient to another hospital or social welfare institution.

The organization of therapeutic nutrition for patients during inpatient treatment in medical organizations is carried out in accordance with Federal Law No. 323-FZ dated November 21, 2011, "On the Protection of Health of Citizens in the Russian Federation", Article 19, Clause 5, "the patient has the right to: 6) receive therapeutic nutrition in case the patient is undergoing treatment in inpatient conditions" and Appendix 3 of the Order of the Russian Ministry of Health No. 1008n dated September 23, 2020, "On Approval of the Procedure for Providing Patients with Therapeutic Nutrition".

7. Additional Information

The prognosis of various forms of protein-energy malnutrition is determined by the nature of the disease and its severity. In mild diet-related conditions and adequate family compliance, the prognosis is favorable.

It has been established that the younger the child and, consequently, the higher the growth rates and metabolic activity—which are inversely proportional to the child's age—the faster malnutrition develops and the more serious its consequences are.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

Anna A. Alekseeva – PhD in Medicine, Deputy Head of the Consultative and Diagnostic Center for Children, Pediatrician, Head of the Multidisciplinary Pediatric Day Hospital, Allergist-Immunologist, Leading Research Scientist at the Department of Clinical Immunology and Allergology, Research Institute of Pediatrics and Child Health, Petrovsky National Research Centre of Surgery, Member of the Union of Pediatricians of Russia.

Aleksandr A. Baranov – Academician of the Russian Academy of Sciences, Professor, MD; Honorary President of the Union of Pediatricians of Russia, Advisor to the Head of the Research Institute of Pediatrics and Child Health, Petrovsky National Research Centre of Surgery, Professor at the Department of Pediatrics and Pediatric Rheumatology, Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Chief Freelance Pediatrician of the Russian Ministry of Health.

Tatiana T. Batysheva – Professor, MD, President of the Association of Pediatric Rehabilitologists of Russia, Director of the Scientific and Practical Center for Children's Psychoneurology of the Moscow Healthcare Department, Head of the Department of Neurology, Physical and Rehabilitation Medicine of Childhood, Faculty of Continuous Medical Education, Peoples' Friendship University of Russia (RUDN University), Chief Freelance Pediatric Rehabilitator of the Russian Ministry of Health, Honored Doctor of Russia.

Irina A. Belyaeva – MD, Head of the Department of Preconceptional, Antenatal, and Neonatal Medicine, Research Institute of Pediatrics and Child Health, Petrovsky National Research Centre of Surgery, Professor at the Department of Faculty Pediatrics, Institute of Motherhood and Childhood, Pirogov Russian National Research Medical University of the Russian Ministry of Health (Pirogov University), Member of the Union of Pediatricians of Russia, Honorary Professor of the Russian Association of Perinatal Medicine Specialists.

Borovik Tatiana Eduardovna – D.Sc. (Medicine), Professor, Honored Scientist of the Russian Federation, Chief Research Scientist at the Laboratory of Nutrition for Healthy and Sick Children, Dietitian at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Pediatrics and Pediatric Rheumatology, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Member of the Children's Health Association, the Association of Medical Geneticists, the Russian Organization of Dietitians, Nutritionists, and Food Industry Specialists, and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN).

Bushueva Tatiana Vladimirovna – D.Sc. (Medicine), Associate Professor, Chief Research Scientist at the Laboratory of Nutrition for Healthy and Sick Children, Dietitian at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Biochemical Genetics and Hereditary Metabolic Diseases at the Institute of Higher Education and Advanced Training of the Academician N.P. Bochkov Medical Genetics Research Center, Member of the Children's Health Association, Member of the Association of Medical Geneticists, Member of the Russian Organization of Dietitians, Nutritionists, and Food Industry Specialists.

Bykova Olga Vladimirovna – D.Sc. (Medicine), Head of the Research Department at the Scientific and Practical Center for Child Psychoneurology of the Moscow Healthcare Department, Professor at the Department of Pediatric Neurology, Physical and Rehabilitation Medicine at the Faculty of Continuous Medical Education, Peoples' Friendship University of Russia (RUDN University), Moscow.

Vishneva Elena Aleksandrovna – D.Sc. (Medicine), Professor of the Russian Academy of Sciences, Deputy Head of the Research Institute of Pediatrics and Child Health at the Petrovsky National Research Center of Surgery, Professor at the Department of Faculty Pediatrics, Institute of Motherhood and Childhood, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health, Member of the Union of Pediatricians of Russia.

Gordeeva Olga Borisovna – Ph.D. (Medicine), Pediatrician, Hematologist, Chief Research Scientist at the Research Institute of Pediatrics and Child Health at the Petrovsky National Research Center of Surgery, Associate Professor at the Department of Faculty Pediatrics, Institute of Motherhood and Childhood, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health, Member of the Union of Pediatricians of Russia.

Guzeva Valentina Ivanovna – D.Sc. (Medicine), Professor, Head of the Department of Neurology, Neurosurgery, and Medical Genetics at the Saint Petersburg State Pediatric Medical University of the Ministry of Health of the Russian Federation, Chief freelance pediatric neurologist of the Ministry of Health of the Russian Federation.

Gureev Sergei Aleksandrovich – Ph.D. (Medicine), Associate Professor at the Department of Healthcare Business Education at RMACPE, Associate Professor at the Department of Public Health and Healthcare with a course on Medical and Social Expertise at the Burnasyan Federal Medical Biophysical Center of FMBA Russia, Member of the Council of Public Organizations for Patient Rights Protection at the Federal Service for Surveillance in Healthcare, Member of the Working Group at the Federation Council on Improving Legislation in Child and Social Nutrition and Developing Domestic Production of Infant Food (0 to 3 years), Executive Director of the Russian Public Association of Children's Nutritionists and Pediatricians (ROSDNP).

Gurova Margarita Mikhailovna – D.Sc. (Medicine), Professor at the Department of Propaedeutics of Childhood Diseases with a course in General Nursing Care at Saint Petersburg State Pediatric Medical University of the Russian Ministry of Health, Member of the Union of Pediatricians of Russia, Member of the Society of Pediatric Gastroenterologists, Hepatologists and Nutritionists, Deputy Chief Medical Officer for Medical Affairs at the Consultative and Diagnostic Center for Children, Saint Petersburg.

Gusev Aleksei Andreevich – Ph.D. (Medicine), Leading Research Scientist, Associate Professor, Pediatric Surgeon at the Department of General and Planned Surgery, Research Institute of Pediatric Surgery, National Medical Research Center for Children's Health of the Russian Ministry of Health, Deputy Chief Medical Officer for Surgery at the National Medical Research Center for Children's Health of the Russian Ministry of Health.

Guseva Irina Mikhailovna – Ph.D. (Medicine), Senior Research Scientist at the Laboratory of Nutrition for Healthy and Sick Children, Dietitian at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Member of the Children's Health Association.

Zavyalova Anna Nikitichna – D.Sc. (Medicine), Gastroenterologist, Dietitian, Pediatrician, Professor at the Department of Propaedeutics of Childhood Diseases with a course in General Nursing Care at Saint Petersburg State Pediatric Medical University of the Russian Ministry of Health, Member of the Russian Organization of Dietitians, Nutritionists, and Food Industry Specialists.

Zvonkova Natalia Georgievna – D.Sc. (Medicine), Associate Professor, Acting Head of the Laboratory of Nutrition for Healthy and Sick Children, Dietitian at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Pediatrics and Pediatric Rheumatology, N.F. Filatov Children's Institute, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University), Member of the Children's Health Association, the Association of Medical Geneticists, and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN).

Ivardava Marika Indikoevna – Ph.D. (Medicine), Head of the General Pediatrics Department, Pediatrician, Head of the Department for the Development of Scientific Approaches to the Management of Children with Motor Disorders at the Research Institute of Pediatrics and Child Health, Petrovsky National Research Center of Surgery, Member of the Union of Pediatricians of Russia.

Ivashkin Vladimir Trofimovich – Academician of the Russian Academy of Sciences, Professor, D.Sc. (Medicine), Chief freelance gastroenterologist of the Russian Ministry of Health, Head of the Department of Propaedeutics of Internal Diseases, Gastroenterology and Hepatology, Director of the V.H. Vasilenko Clinic of Propaedeutics of Internal Diseases, Gastroenterology and Hepatology, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University). President of the Scientific Society for the Promotion of Clinical Study of the Human Microbiome (SSCHM), President of the Russian Gastroenterological Association (RGA).

Kaitukova Elena Vladimirovna – Ph.D. (Medicine), Deputy Head for Medical Activities – Head of the Consultative and Diagnostic Center for Children, Gastroenterologist, Leading Research Scientist at the Department of Orphan Diseases and Prevention of Disabling Conditions, Research Institute of Pediatrics and Child Health, Petrovsky National Research Center of Surgery, Associate Professor at the Department of Faculty Pediatrics, Institute of Motherhood and Childhood, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health, Member of the Union of Pediatricians of Russia.

Klimov Yuri Andreevich – Ph.D. (Medicine), Deputy Director for Medical Work at the Scientific and Practical Center for Pediatric Psychoneurology of the Moscow Healthcare Department; Head of the Department of Neurology and Neurosurgery at the Russian State Social University.

Komarova Elena Vladimirovna – D.Sc. (Medicine), Deputy Head for the Expertise of Innovative Treatment and Rehabilitation Methods, Gastroenterologist, Chief Research Scientist at the Department of Orphan Diseases and Prevention of Disabling Conditions, Research Institute of Pediatrics and Child Health, Petrovsky National Research Center of Surgery, Professor at the Department of Faculty Pediatrics, Institute of Motherhood and Childhood, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health, Member of the Union of Pediatricians of Russia.

Lukoyanova Olga Leonidovna – D.Sc. (Medicine), Associate Professor, Chief Research Scientist at the Laboratory of Nutrition for Healthy and Sick Children, Highest Category Pediatrician at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Pediatrics and Public Health, Institute of Medical Training, National Medical Research Center for Children's Health, Member of the Children's Health Association, Member of ESPGHAN.

Makarova Svetlana Gennadievna – D.Sc. (Medicine), Professor, Deputy Director for Research at the National Medical Research Center for Children's Health of the Russian Ministry of Health, Professor at the Department of Pediatrics and Public Health, Institute of Medical Training, National Medical Research Center for Children's Health, Allergist-Immunologist, Chief freelance specialist of the Russian Ministry of Health for medical care in educational institutions in the Central Federal District, Member of the Children's Health Association.

Naletov Andrei Vasilievich – D.Sc. (Medicine), Professor, Head of the Department of Pediatrics No. 2 at Donetsk National Medical University of the Russian Ministry of Health, Chief freelance pediatric gastroenterologist of the Ministry of Health of the Donetsk People's Republic, President of the regional branch of the All-Russian Public Organization "Union of Pediatricians of Russia" in the Donetsk People's Republic.

Namazova-Baranova Leila Seymurovna – Academician of the Russian Academy of Sciences, Professor, D.Sc. (Medicine), President of the Union of Pediatricians of Russia; Past President of EPA/UNEPSA; Head of the Research Institute of Pediatrics and Child Health, Petrovsky National Research Center of Surgery, Head of the Department of Faculty Pediatrics, Institute of Motherhood and Childhood, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health, Chief freelance pediatric specialist in preventive medicine of the Russian Ministry of Health.

Nikityuk Dmitry Borisovich – Academician of the Russian Academy of Sciences, D.Sc. (Medicine), Professor, Director of the Federal Research Centre of Nutrition and Biotechnology.

Novikova Valeria Pavlovna – D.Sc. (Medicine), Professor, Head of the Department of Propaedeutics of Childhood Diseases, Head of the Laboratory of Medical and Social Problems in Pediatrics at the Research Center of Saint Petersburg State Pediatric Medical University.

Pavlovskaya Elena Vyacheslavovna – D.Sc. (Medicine), Leading Research Scientist at the Department of Pediatric Gastroenterology, Hepatology and Dietotherapy, Federal Research Centre of Nutrition and Biotechnology; Professor at the Department of Dietetics and Nutrition, Russian Medical Academy of Continuous Professional Education of the Russian Ministry of Health.

Mariya M. Platonova – PhD in Medical Sciences, Researcher at the Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery; Pulmonologist.

Elena V. Polevichenko – MD, PhD, Professor at the Department of Oncology, Hematology and Radiology, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Professor; Chief Freelance Specialist in Pediatric Palliative Care of the Russian Ministry of Health.

Elena A. Poluektova – MD, PhD, Professor at the Department of Propaedeutics of Internal Diseases, Gastroenterology and Hepatology, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University). Vice President of the Scientific Society for the Promotion of Clinical Study of the Human Microbiome (SSCHM), Member of the Russian Gastroenterological Association (RGA).

Ekaterina A. Pyryeva – PhD in Medical Sciences, Associate Professor, Head of the Laboratory of Age-Related Nutrioneurology, Federal Research Center of Nutrition and Biotechnology; Associate Professor at the Department of Dietetics and Nutrition, Russian Medical Academy of Continuous Professional Education (RMAPO) of the Russian Ministry of Health.

Adilya I. Safronova – PhD in Medical Sciences, Leading Researcher at the Laboratory of Age-Related Nutrioneurology, Federal Research Center of Nutrition and Biotechnology.

Liliya R. Selimzyanova – PhD in Medical Sciences, Head of the Department of Standardization and Study of Evidence-Based Medicine Foundations, Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery; Associate Professor at the Department of Pediatrics and Pediatric Rheumatology, I.M. Sechenov First Moscow State Medical University (Sechenov University); Associate Professor at the Department of Faculty Pediatrics, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Member of the Union of Pediatricians of Russia.

Vera A. Skvortsova – MD, PhD, Chief Researcher at the Laboratory of Healthy and Sick Child Nutrition, Dietitian at the National Medical Research Center for Children's Health of the Russian Ministry of Health; Professor at the Department of Pediatrics, Moscow Regional Research Clinical Institute (MONIKI) named after M.F. Vladimirsky, member of the Children's Health Association, member of the Russian Organization of Dietitians, Nutritionists and Food Industry Specialists.

Ina Sokolov – PhD in Medical Sciences, Senior Researcher at the Laboratory of Healthy and Sick Child Nutrition, Pediatrician at the National Medical Research Center for Children's Health of the Russian Ministry of Health; Associate Professor at the Department of Pediatrics and Public Health, Institute of Medical Training, National Medical Research Center for Children's Health; Member of the Children's Health Association.

Tatyana N. Sorvacheva – MD, PhD, Head of the Department of Dietetics and Nutrition, Russian Medical Academy of Continuous Professional Education (RMAPO) of the Russian Ministry of Health.

Antonina V. Starodubova – MD, PhD, Associate Professor, Deputy Director for Research and Clinical Work, Federal Research Center of Nutrition and Biotechnology; Head of the Department of Faculty Therapy, Institute of Clinical Medicine, Pirogov Russian National Research Medical University.

Tatyana V. Strokova – MD, PhD, Professor of the Russian Academy of Sciences, Head of the Department of Pediatric Gastroenterology, Hepatology and Dietotherapy, Federal Research Center of Nutrition and Biotechnology; Head of the Department of Gastroenterology and Dietetics, Institute of Continuing Professional Education, Pirogov Russian National Research Medical University.

Andrey N. Surkov – MD, PhD, Head of the Department of Gastroenterology for Children (Inpatient Unit for Children), Head of the Department of Scientific Foundations of Pediatric Gastroenterology, Hepatology and Metabolic Disorders, Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery; Professor at the Department of Faculty Pediatrics, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Member of the Union of Pediatricians of Russia.

Valentin V. Sytkov – PhD in Medical Sciences, Associate Professor at the Department of Pediatric Surgery, N.A. Semashko Research Institute of Clinical Medicine, Russian University of Medicine of the Russian Ministry of Health; Coloproctologist, Pediatric Surgeon at the Surgical Department, Federal National Medical Research Center of Children and Adolescents of the Federal Medical-Biological Agency (FMBA) of Russia; Member of the Union of Pediatricians of Russia, Member of the Russian Association of Pediatric Surgeons, Russian Society of Colorectal Surgeons.

Nataliya N. Taran – PhD in Medical Sciences, Senior Researcher at the Department of Pediatric Gastroenterology, Hepatology and Dietotherapy, Federal Research Center of Nutrition and Biotechnology; Associate Professor at the Department of Gastroenterology and Dietetics, Institute of Continuing Professional Education, Pirogov Russian National Research Medical University.

Sergey V. Tikhonov – PhD in Biology, Academic Secretary, Scientific and Practical Center for Pediatric Psychoneurology of the Moscow City Health Department; Associate Professor at the Department of Neurology, Physical and Rehabilitation Medicine, Faculty of Continuous Medical Education, Medical Institute of RUDN University, Moscow.

Rustem F. Tepaev – MD, PhD, Head of the Anesthesiology and Intensive Care Unit, Z.A. Bashlyaeva Children's City Clinical Hospital; Professor at the Department of Pediatrics and Pediatric Rheumatology, I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Russian Ministry of Health.

Anna Yu. Tomilova – PhD in Medical Sciences, Associate Professor at the Department of Faculty Pediatrics, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Allergist-Immunologist at the Allergology Department, Federal National Medical Research Center of Children and Adolescents of the FMBA of Russia; Member of the Union of Pediatricians of Russia.

Tatyana V. Turti – MD, PhD, Chief Researcher at the Department of Preconceptional, Antenatal and Neonatal Medicine, Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery; Professor at the Department of Faculty Pediatrics, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Member of the Union of Pediatricians of Russia.

Viktor A. Tutelyan – Academician of the Russian Academy of Sciences, MD, PhD, Professor, Scientific Advisor of the Federal Research Center of Nutrition and Biotechnology. President of the Russian Organization of Dietitians, Nutritionists and Food Industry Specialists.

Anatoly I. Ulyanin – Physician at the Department of Chronic Intestinal and Pancreatic Diseases, V.Kh. Vasilenko Clinic of Propaedeutics of Internal Diseases, Gastroenterology and Hepatology, University Hospital No. 2, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health; Member of the Scientific Society for the Promotion of Clinical Study of the Human Microbiome (SSCHM), Member of the Russian Gastroenterological Association (RGA).

Nataliya V. Ustinova – MD, PhD, Psychiatrist, Healthcare Administrator, Head of the Department of Social Pediatrics and Organization of Multidisciplinary Child Support, Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery, G.E. Sukhareva Scientific and Practical Center for Mental Health of Children and Adolescents of the Moscow Healthcare Department.

Marina V. Fedoseenko – PhD in Medical Sciences, Head of the Department for the Development of Scientific Approaches to Immunization of Patients with Health Deviations and Chronic Diseases, Leading Researcher, Pediatrician at the Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery; Associate Professor at the Department of Faculty Pediatrics, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Member of the Union of Pediatricians of Russia.

Andrey P. Fisenko – MD, PhD, Professor, Honored Doctor of the Russian Federation, Director of the National Medical Research Center for Children's Health of the Russian Ministry of Health, Chairman of the Scientific and Practical Society of the Children's Health Association.

Anatoly I. Khavkin – MD, PhD, Professor, Head of the A.V. Mazurin Moscow Regional Center for Pediatric Gastroenterology and Hepatology, Research Clinical Institute of Childhood of the Ministry of Health of the Moscow Region; Professor at the Department of Pediatric Diseases, Medical Institute of Belgorod State National Research University; Chairman of the Society of Pediatric Gastroenterologists, Hepatologists and Nutritionists of Russia; Member of the Union of Pediatricians of Russia.

Kamilla E. Efendieva – PhD in Medical Sciences, Deputy Head for International Relations and Educational Activities, Leading Researcher, Allergist-Immunologist at the Research Institute of Pediatrics and Children's Health, Petrovsky National Research Centre of Surgery; Associate Professor at the Department of Faculty Pediatrics, Institute of Mother and Child, Pirogov Russian National Research Medical University (Pirogov University) of the Russian Ministry of Health; Member of the Union of Pediatricians of Russia.

Ekaterina A. Yablokova – PhD in Medical Sciences, Associate Professor at the Department of Children's Diseases, I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Russian Ministry of Health; Member of the Union of Pediatricians of Russia.

Sergey P. Yatsyk – MD, PhD, Corresponding Member of the Russian Academy of Sciences, Professor at the Department of Pediatric Surgery, Russian Medical Academy of Continuous Professional Education (RMAPO); Member of the All-Russian Public Organization "Russian Association of Pediatric Surgeons".

Conflict of interest: none.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. Pediatricians

2. District pediatricians

3. Dietitians

4. Anesthesiologists-intensivists

5. Neurologists

6. General practitioners (family physicians)

7. Pediatric endocrinologists;

8. Gastroenterologists

9. Psychiatrists

10. Pediatric surgeons

11. Palliative care physicians

12. Residents and postgraduate students

13. Faculty members of pediatric departments at medical universities

Table 1. Scale for assessing the levels of evidence (LE) for diagnostic methods (diagnostic interventions)

Table 2. Scale for assessing levels of evidence (LoE) for prevention, treatment, and rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitation interventions)

Table 3. Scale for assessing the levels of recommendation persuasiveness (LRP) for prevention, diagnostic, treatment, and rehabilitation methods, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Procedure for updating clinical guidelines.

The mechanism for updating clinical guidelines provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data on the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

1. Order of the Ministry of Health and Social Development of the Russian Federation No. 366n dated April 16, 2012, "On Approval of the Procedure for Providing Pediatric Care";

2. Order of the Ministry of Health of the Russian Federation No. 920n dated November 15, 2012, "On Approval of the Procedure for Providing Medical Care to the Population in the Field of Dietetics".

3. Order of the Russian Ministry of Health No. 1094n dated November 24, 2021, "On Approval of the Procedure for Prescribing Medicinal Products, Prescription Form Templates for Medicinal Products, the Procedure for Issuing These Forms, Their Accounting and Storage, Prescription Form Templates Containing Prescriptions for Narcotic Drugs or Psychotropic Substances, the Procedure for Their Manufacture, Distribution, Registration, Accounting and Storage, as well as the Rules for Issuing Prescription Forms, Including in the Form of Electronic Documents";

4. Order of the Government of the Russian Federation No. 3053-r dated December 31, 2018, "On Approval of Lists of Medical Devices Implanted into the Human Body When Providing Medical Care Within the Framework of the State Guarantee Program for Free Medical Care to Citizens and Dispensed by Prescription for Medical Devices Upon Provision of a Set of Social Services";

5. International Classification of Diseases, Injuries and Causes of Death (ICD-10);

6. Order of the Russian Ministry of Health No. 205n dated May 2, 2023 (as amended on December 4, 2023) "On Approval of the Nomenclature of Positions of Medical Workers and Pharmaceutical Workers" (Registered with the Ministry of Justice of Russia on June 1, 2023, No. 73664);

4. Order of the Ministry of Health of the Russian Federation No. 541n dated July 23, 2010. Unified Qualifications Handbook of Positions of Managers, Specialists, and Employees, section Qualifications Characteristics of Positions of Workers in Healthcare;

5. Federal Law No. 489-FZ dated December 25, 2018, "On Amendments to Article 40 of the Federal Law 'On Compulsory Medical Insurance in the Russian Federation' and the Federal Law 'The Fundamentals of Protecting Citizens' Health in the Russian Federation' Regarding Clinical Practice Guidelines";

6. Order of the Russian Ministry of Health No. 103n dated February 28, 2019, "On Approval of the Procedure and Deadlines for the Development of Clinical Practice Guidelines, Their Revision, the Standard Template of Clinical Practice Guidelines and Requirements for Their Structure, Composition and Scientific Validity of Information Included in Clinical Practice Guidelines";

7. Order of the Russian Ministry of Health No. 804n dated October 13, 2017, "On Approval of the Nomenclature of Medical Services";

8. Order of the Ministry of Health and Social Development of the Russian Federation "On the Procedure for the Use of Medicinal Products in Patients for Vital Indications" dated August 9, 2005, No. 494;

9. Order of the Russian Ministry of Health No. 1008n dated September 23, 2020, "On Approval of the Procedure for Providing Patients with Medical Nutrition";

10. Draft GOST "PRODUCTS FOR ENTERAL NUTRITION Classification".

Appendix A3.1 Factors affecting the nutritional status of patients with neurological pathology and measures for their correction [16]

Appendix A3.2 WHO growth standards (2007) for assessing physical development in children (Z-scores)

Appendix A3.2.1 WHO Growth Standards (2007) for assessing the physical development of children (Z-scores) (children from birth to 5 years)

Weight-for-length/height (girls) from birth to 5 years

Weight-for-length/height (boys) from birth to 5 years

BMI-for-age (girls) from birth to 5 years

BMI-for-age (boys) from birth to 5 years

Weight-for-age (girls) from birth to 5 years

Weight-for-age (boys) from birth to 5 years

Length/height-for-age (girls) from birth to 5 years

Length/height-for-age (boys) from birth to 5 years

Appendix A3.2.2 WHO Growth Reference (2007) for assessing the physical development of children (Z-scores) (children aged 5 to 19 years)

Height-for-age (girls) from 5 to 19 years

Height-for-age (boys) from 5 to 19 years

BMI-for-age (girls) from 5 to 19 years

BMI-for-age (boys) from 5 to 19 years

Appendix A3.3 Weight gain norms at different ages

Weight gain standards at different ages over time [171, 172].

0–1 year

0–3 months 30 g/day

3–6 months 20 g/day

6–12 months 10 g/day

1–3 years 2.25 kg/year

4–9 years 2.75 kg/year

10–18 years 5–6 kg/year

Appendix A3.4 Determination of mid-upper arm circumference (MUAC), Determination of mid-upper arm muscle circumference (MUAMC)

Measurement of mid-upper arm circumference (MUAC)

Determination of mid-upper arm circumference is necessary, inter alia, to determine mid-upper arm muscle circumference (MUAMC).

1. Use a non-stretch measuring tape. The tape must provide measurement accuracy up to 0.1 cm.

2. The arm (non-dominant) should hang freely along the torso.

3. Measure the distance between the acromial process of the scapula (acromion) and the olecranon process (tip of the ulna), determine the midpoint between these points, and mark it.

4. Measure the mid-upper arm circumference. Wrap the measuring tape snugly around the arm without compressing the soft tissues. Record the value.

Determination of Mid-Upper Arm Muscle Circumference

Mid-upper arm muscle circumference (MAMC) is calculated using the values of mid-upper arm circumference (MUAC) and triceps skinfold thickness (TST). It allows for the assessment of somatic protein stores.

MAMC, mm = MUAC (mm) – 3.14 × TST (mm)

Appendix A3.5 Measurement of triceps skinfold thickness (skinfold caliperometry)

Measurement of triceps skinfold thickness

Measurement of triceps skinfold thickness (TST) is performed to assess body fat mass reserves.

Rules for TST measurement:

1. The arm (non-dominant) should hang freely along the torso.

2. Measure the distance between the acromial process of the scapula (acromion) and the olecranon process (tip of the ulna), determine the midpoint between these points, and mark it.

3. Approximately 1 cm above the midpoint, pinch the skin over the triceps muscle along with the subcutaneous fat layer in a direction perpendicular to the bone (on the back of the arm). Make sure you grasp only the skin and adipose tissue, but not the muscle itself. If you are unsure, flex the arm. If you have grasped the muscle, you will feel it stretch upon flexion. Release the skin and repeat the procedure from the beginning.

4. Apply the caliper 1 cm below the site pinched by your fingers and compress the skinfold. Do not release your fingers until the measurement is completed.

5. After three seconds, take the instrument reading at the nearest mm value. Record the reading.

6. Release the caliper and let go of your fingers.

7. Repeat the measurement three times. Determine the mean value of the three measurements. If any value differs from the mean by more than 10%, exclude it and measure the skinfold thickness a fourth time.

Appendix A3.6 Anthropometric percentiles for mid-upper arm circumference (MUAC), mid-upper arm muscle circumference (MAMC), and triceps skinfold thickness measurements [173]

Mid-Upper Arm Circumference (mm). Percentiles. Males

Mid-Upper Arm Circumference (mm). Percentiles. Males.

Mid-Upper Arm Circumference (mm). Percentiles. Females [Am J Clin Nutr., 1981]

Mid-Upper Arm Circumference (mm). Percentiles. Females.

Triceps Skinfold Thickness (mm). Percentiles. Males.

Triceps Skinfold Thickness (mm). Percentiles. Females.

Appendix A3.7 Slaughter M.H. et al. (1988) equation for determining body fat percentage based on TST and SSST measurements

The Slaughter M.H. et al. (1988) equation is used to determine the percentage of body fat based on TST and SSST measurements [36,174].

Appendix A3.8 Formulas for calculating height from knee height in children with cerebral palsy [53,174]

Note: H – height, KH – knee height

Appendix A3.9 Technique for measuring lower leg length and formula for determining estimated child height

Technique for measuring lower leg length: the child may sit or lie in a supine position; measurements are taken on the medial surface of the lower leg. The distance from the contact point of the tibia and femur to the distal edge of the medial malleolus is measured.

Formula for determining estimated child height

H(cm) = (3.26 × LLL) + 30.8

where H is child height in cm, and LLL (cm) is lower leg length.

Appendix A3.10 Sample schedule for clinical and laboratory monitoring of patients receiving enzyme replacement therapy in outpatient settings

Table. Clinical and laboratory monitoring of patients receiving enzyme replacement therapy in outpatient settings [117].

Appendix A3.11 Monitoring parameters in children receiving parenteral nutrition [82]

Appendix A3.12 Norms of physiological requirements for energy and nutrients for various population groups of the Russian Federation (MR 2.3.1.0253-21)

Table. Norms of physiological requirements for energy and nutrients for various population groups of the Russian Federation (MR 2.3.1.0253-21) [79].

Appendix A3.13 Principles of malnutrition correction depending on its severity

Mild undernutrition / risk of undernutrition (mild) (BMI Z-score / weight-for-height Z-score / weight-for-age Z-score from -1.0 to -1.99)

If mild undernutrition is identified, dietary modification is carried out using natural foods, optimizing the diet schedule, and/or adjusting single portion sizes, taking into account the underlying disease. The energy value and amount of main macronutrients should correspond to the recommended dietary allowances (RDAs) or individual dietary allowances (IDAs). As a source of nutrients and energy, the additional introduction of foods with high energy density (cereals, meat, dairy products, vegetable oils, etc.) into the diet is indicated.

After dietary modification, nutritional status should be assessed after 1 month. If a positive body weight trajectory is registered, continue medical nutrition therapy in the same volume under the control of anthropometric parameters at least once every 3 months.

If there is no effect from the ongoing medical nutrition therapy, nutritional support is prescribed for additional meals in the amount of 10%–15% of the caloric content of the recommended dietary allowances, taking into account age and sex [79]. The norms of physiological requirements for energy and nutrients for various population groups of the Russian Federation are presented in Appendix A 3.11.

Moderate undernutrition (BMI Z-score / weight-for-height Z-score / weight-for-age Z-score from -2.0 to -2.99)

Identified moderate undernutrition requires correction of the energy value and macronutrient composition of the diet using natural foods with high energy density in patients receiving a standard diet, and the prescription of oral nutritional support at a starting volume of 15% of the recommended dietary allowance, taking into account the nature and features of the underlying disease. Specialized enteral formulas for nutritional support are recommended to be prescribed as additional meals (second breakfast, afternoon snack, or at bedtime), monitoring product tolerance [79].

After dietary modification, nutritional status should be assessed after 1 month. If a positive body weight trajectory is registered, continue medical nutrition therapy in the same volume under the control of anthropometric parameters evaluated at least once every 1–3 months until nutritional status normalizes.

Once nutritional status parameters normalize, nutritional support may be discontinued (or the volume of the enteral formula revised, depending on the disease/condition).

In the absence of a positive trajectory, a reassessment of actual nutrition is performed, the compliance of the enteral formula with age, clinical presentation, and comorbid pathology is evaluated. The volume of nutritional support is increased to provide the required amount of protein and non-protein calories.

Re-correction of the diet and nutritional support is carried out under the control of anthropometric parameters at least once every 3 months.

Severe undernutrition (BMI Z-score / weight-for-height Z-score / weight-for-age Z-score <-3.0)

In case of identified severe undernutrition in patients receiving a standard diet, correction is carried out through natural foods (their quantity and quality) and the prescription of oral nutritional support. The volume of the specialized enteral formula is selected individually, taking into account protein and energy requirements, product tolerance, and the nature and course of the underlying disease. The enteral formula is prescribed as additional meals (second breakfast, afternoon snack, and at bedtime), while main meals (breakfast, lunch, and dinner) are formed from natural foods [79].

Monitoring of anthropometric parameters during medical nutrition therapy is carried out at least once every 1 month.

If there is a positive trajectory in nutritional status parameters, continue medical nutrition therapy, adjusting the volume of nutritional support to account for changes in the severity of undernutrition.

In the absence of a positive trajectory, laboratory and instrumental examinations, a re-analysis of actual nutrition and the volume of nutritional support are performed, and the compliance of the enteral formula with age, the clinical presentation of the underlying disease, and comorbid pathology is evaluated.

Dietary modification must take into account the effectiveness of oral food intake.

Diagnosed oromotor disorders and dysphagia of any degree combined with a lack of growth and weight gain, stagnation, or negative body weight trajectory are indications for organizing enteral tube feeding (tube/stoma) [38, 80, 81].

Appendix A3.14 Types of feeding tubes for nutritional support

Characteristics of tubes for nutritional support.

I. By the site of placement in the gastrointestinal tract:

1. Nasogastric tubes – designed to transport food into the stomach.

2. Nasoenteric tubes – deliver food into the intestine.

II. By the material of the tube

1. Enteral nutrition tubes made of polyvinyl chloride (PVC) are the most common. The structure of a PVC tube includes plasticizers: diethyl phthalate or polyadipate. Diethyl phthalate rapidly binds to the fat component of the nutrient formula and loses its elasticity, which can lead to the risk of pressure ulcers in the nasopharynx and gastric perforation. Such a tube must be replaced every 3–7 days. If polyadipate is used as a plasticizer, the tube can be used for up to 2–3 weeks.

2. Silicone tubes have a soft structure. They contain a tip weight or weighted tip for radiopacity and advancement into the stomach. They withstand sterilization well and are not sensitive to the acidic environment of the stomach.

3. Polyurethane tubes contain a radiopaque line throughout their length and have sufficient rigidity, making it possible to use them for administration not only into the stomach, but also into the duodenum and jejunum. They are not affected by gastric juice, allowing a duration of use of up to 2–4 weeks.

III. By structure:

1. Single-lumen.

2. Multi-lumen (2- or 3-channel), which allows not only feeding the patient, but also flushing the system, administering additional nutrition, or collecting material for diagnostic testing.

Technique for gastric tube placement:

1. Determine the length of the intracorporeal part of the tube. Rule: the sum of the distances from the xiphoid process to the tip of the nose, and from the tip of the nose to the earlobe (tragus of the ear) will equal the length of the tube inserted into the stomach. If it is necessary to place the tube in the duodenum, add another +20–30 cm; if in the jejunum, +40–50 cm.

2. Place a mark on the tube – this will be the insertion depth of the tube; the mark should remain at the level of the nose.

3. Lubricate the insertion part of the tube with sterile liquid petrolatum or a special lidocaine gel.

4. After inserting the tube into the stomach, be sure to verify its location by aspirating gastric contents with a syringe and determining the pH of the aspirate (since if the tube enters the respiratory tract, mucus/sputum can be mistakenly taken for gastric contents), or under X-ray control.

5. If further advancement of the tube into the intestine is necessary, place the patient on their right side, and every 20–30 minutes slowly advance the tube by 5 cm until the set mark is reached.

6. Verification of the tube's location can be checked using ultrasound diagnostics, radiologically (if the inserted tube has a weighted tip or contains a radiopaque line), as well as by aspirating gastric contents with a syringe and determining the pH of the aspirate using test strips. You can also inject 20–30 ml of air with a syringe while auscultating over the stomach area. Characteristic "gurgling" indicates that the tube is in the stomach (mystoma.ru).

Gastrostomies.

Gastrostomy placement techniques:

1. Endoscopic (using an endoscope):

- Percutaneous endoscopic gastrostomy (placement of a gastrostomy into the stomach through the anterior abdominal wall under endoscopic guidance).

- Direct puncture gastrostomy placement using introducers.

2. Surgical: open or laparoscopic technique.

3. Radiological (under fluoroscopic guidance).

Types of gastrostomy tubes:

1. Non-balloon type gastrostomy tubes (PEG). With proper functioning and unchanged appearance, use for more than 1 year is permitted. Installation and replacement of non-balloon gastrostomy tubes are performed under general anesthesia.

2. Balloon type gastrostomy tube: the tube is inserted into the stomach, the balloon is inflated using a syringe filled with sterile water, due to which the tube is held in the stomach without falling out. Installed for a period of 4–6 months. Installation is performed under general anesthesia, and replacement is carried out at home without anesthesia.

▪ Long

▪ Low-profile

Low-profile small-sized gastrostomy tube, does not require additional fixation with adhesive tape. Highly reliable port cap prevents spontaneous tube opening and leakage. The antireflux valve prevents backflow of gastric contents. Air circulation around the stoma is facilitated. The child cannot accidentally pull out the tube from themselves or someone else who has it inserted, due to the lack of a long "tail". The material of the gastrostomy tube is hypoallergenic. Preference is given to medical-grade silicone free of latex, diethylhexyl phthalate, and other substances causing allergies and other adverse reactions. The radiopaque line along the entire length of the tube allows for fluoroscopic visualization. 

Recommendations for gastrostomy care and feeding:

1. Daily wash the skin around the stoma (gastrostomy opening) and under the external retention device, or the tube cap (if it is a low-profile gastrostomy) with warm water and soap. You can also take a regular bath or shower. Important! A new tube must not be immersed in water for three weeks after surgery. After showering, make sure that the area around the stoma is thoroughly dried. It is not recommended to use talcum powder around the gastrostomy. As prescribed by a doctor, in addition to washing with soap and water, an alcohol-free antiseptic solution (e.g., benzyldimethyl-myristoylamino-propylammonium, octenidine, etc.) can be used.

2. Occlusive dressings must not be used over the gastrostomy after the stoma is formed (a dressing is necessary for the first 1-2 weeks after gastrostomy placement, as at this stage the wound is surgical, and a dressing is required). An occlusive dressing can contribute to the development of pressure ulcers and granulation tissue on the skin, as well as an increase in bacterial count.

3. After the stoma tract is formed, rotate the tube 360 degrees around its axis every day. Move long types of tubes (balloon and non-balloon) up and down by 1.0–1.5 cm to prevent them from sticking to the stoma walls and to prevent the overgrowth of granulation tissue.

4. If the patient has a long tube (balloon or non-balloon) rather than a low-profile one, it is necessary to check the insertion depth of the tube and the external retention device daily (approximately 2–5 mm from the skin surface). To do this, daily assess the depth of the tube by external markers. After cleaning the gastrostomy opening and the tube itself, gently check every day whether the internal bolster or balloon rests against the anterior abdominal wall (you can gently pull it towards you until it stops), and then lower the external fixation device to the desired mark.

• The external retention device must not be displaced for two weeks after surgery to ensure the gastrostomy tube is properly positioned. If compression and discomfort are observed during this time, a specialist must be consulted.

• During the placement of certain gastrostomies, additional clips are applied for gastropexy (fixation of the stomach to the anterior abdominal wall to prevent reflux). The duration of keeping the clips in place is determined by the surgeon, after which they either fall off independently or are removed by a doctor.

• Check the area around the stoma for irritation, redness, or swelling. If these occur, a specialist consultation is required.

5. If a balloon gastrostomy tube is present, check the amount of water in the balloon every 1-2 weeks. The required filling volume is indicated in the instructions. If the balloon is filled with too much water, it may burst.

• If the gastrostomy was recently placed, do not perform any manipulations with the gastrostomy tube balloon for 2–3 weeks after surgery to ensure the stomach adheres closely to the abdominal wall.

• Do not fill the balloon with other solutions (e.g., sodium chloride 0.9% solution, nitrofurazone, etc.). Only sterile (boiled) water may be used.

7. To prevent clogging, the gastrostomy tube should be flushed with water before and after each feeding and medication administration. Flush the tube with a bolus of water in an amount of at least 20–40 ml (unless fluid intake is restricted), or 10 ml in newborns.

8. In case of tube occlusion, attach a syringe filled with 10–20 ml of warm water to it. Gently pull the plunger and then push it to dislodge the clog. If the clog remains in place, repeat the previous step. Gentle aspiration alternating with pressure on the plunger will resolve most clogs. If this does not help, consult your attending physician.

9. If oral feeding is reduced or completely absent, plaque can rapidly accumulate on the teeth. Oral hygiene must be maintained, and teeth must be brushed twice a day. Poor oral hygiene causes pain and promotes the development or maintenance of infection and inflammatory conditions in the nasopharynx and upper respiratory tract.

Appendix A3.15 Formulas for calculating basal energy expenditure in children (WHO, Harris-Benedict, pediatric-adapted, Schofield)

Table. FAO/WHO/UNU equations for basal energy requirements in children.

Table. Calculation of energy requirements in children across different age periods using the Harris-Benedict formula

BEE – basal energy expenditure; REE – resting energy expenditure (resting metabolic rate).

Table. Calculation of basal energy requirements using the Schofield formula

Quoted from Schofield WN, where W is body mass; H is height.

Appendix A3.16 Coefficients for determining protein requirements depending on the child's activity factor, underweight, growth factor, and disease status to refine the volume of nutritional support, and factors influencing energy metabolism in patients

Table. Coefficients for determining protein requirements depending on the child's activity factor, underweight, growth factor, and disease status to refine the volume of nutritional support [89].

To calculate energy requirements in neurological patients with severe motor impairments (GMFCS levels IV–V), the Krick formula is used.

BER – basal energy requirement.

Muscle tone factor: 0.9 – decreased; 1.0 – normal; 1.1 – increased;

Activity factor: 1.15 – bedridden patient; 1.2 – wheelchair-bound patient; 1.25 – crawling; 1.3 – ambulatory patient;

Growth factor: 5 kcal/g of desired daily weight gain.

Calculated parameters in certain cases do not allow achieving optimal nutritional status parameters, as energy requirements may be influenced by other factors.

Table. Factors affecting energy metabolism in patients

Appendix A3.17 Criteria for assessing dehydration severity in children

Table. Criteria for assessing the severity of dehydration in children [122, 123].

Fluid calculation for dehydration replacement can also be performed using hematocrit:

whereHt_p— patient's hematocrit,Ht_n — normal hematocrit,M— child's weight in kilograms,K— extracellular fluid coefficient, %: (45 for preterm infants, 40 for newborns, 30 for infants, 25 for young children, 20 for older children).Appendix A3.14presents recommendations for the volume of infusion therapy for correcting dehydration in children of various ages.

Appendix A3.18 Volume of infusion therapy for dehydration correction in children (mL/kg/day)

Table. Volume of infusion therapy for the correction of dehydration in children (ml/kg/day) [122, 123].

Appendix A3.19 Basic requirement for electrolytes and minerals in patients on parenteral nutrition

Table. Basic requirement for electrolytes and minerals in patients on parenteral nutrition [121, 126].

¹ administered from the 2nd week of PN

Appendix A3.20 Daily micronutrient requirements in children

Table. Daily micronutrient requirements of children [129].

^{1 —} Initiated from the 2nd week of PN; ² — Initiated from the 4th week of PN.

Appendix A3.21 Children's daily energy requirement depending on the phase of the disease (kcal/kg/day)

Table. Children's daily energy requirement depending on the phase of the disease (kcal/kg/day) [118, 123, 131].

Appendix A3.22 Dextrose** infusion rate depending on age and condition of children, mg/kg/min (g/kg/day)

Table. Dextrose** infusion rate depending on age and condition of children, mg/kg/min (g/kg/day) [118, 123, 131].

The infusion rate of dextrose** in term newborns is 2.5–5 mg/kg/min on the first day (5.8–11.5 g/kg/day); over 2–3 days, the infusion rate of dextrose** may be increased to 5–10 mg/kg/min (7.2–14.4 g/kg/day) [132].

Appendix A3.23 Types of lipid emulsions for parenteral nutrition**

Fat emulsions for parenteral nutrition of three generations:

I - Lipid emulsions for parenteral nutrition** (long-chain triglyceride (LCT) fat emulsions based on soybean oil);

II - Lipid emulsions for parenteral nutrition** (soybean oil-based fat emulsion containing equivalent amounts of long- and medium-chain triglycerides (LCT/MCT). This fat emulsion contains fewer polyunsaturated fatty acids (PUFAs) than LCT);

III - Lipid emulsions for parenteral nutrition** (combined emulsions with the addition of omega-3 fatty acids: (soybean oil/medium-chain triglycerides, α-tocopherol).

Appendix A3.24 Amino acid requirement of children with EN on PN depending on age (in stable condition)

Table. Amino acid requirement of children with EN on PN depending on age (in stable condition) [136].

Appendix A3.25 Example of parenteral nutrition calculation in children

Calculation of daily fluid volume using the formula:

V_int = FP + FLD + FLPN

- Decision-making regarding the need for transfusion therapy and its volume (red blood cell suspension (Red blood cell suspension / Red blood cell suspension with buffy coat removed / Leukoreduced red blood cell suspension / Red blood cell suspension obtained by apheresis / Thawed, washed red blood cell suspension), platelet concentrate (Platelet concentrate from a unit of blood / Leukoreduced platelet concentrate from a unit of blood / Pooled platelet concentrate from a unit of blood / Pooled platelet concentrate from a unit of blood in additive solution / Pooled leukoreduced platelet concentrate from a unit of blood / Pooled pathogen-reduced platelet concentrate from a unit of blood / Platelet concentrate obtained by apheresis / Leukoreduced platelet concentrate obtained by apheresis / Pathogen-reduced platelet concentrate obtained by apheresis / Platelet concentrate obtained by apheresis in additive solution / Cryopreserved, thawed platelet concentrate), fresh frozen plasma, normal human immunoglobulin**).

- Calculation of the volume of amino acids for parenteral nutrition** and infusion rate (starting dose from 0.5–1 g/kg/day, increasing daily by 0.5–1 g/kg/day, with total PN — 24 h, maximum rate 0.1–0.15 g/kg/h).

- Calculation of the volume of fat emulsion for parenteral nutrition** and infusion rate — with total PN 24 h (starting dose 0.5–1 g/kg/day, increasing the dose daily by 0.5–1 g/kg/day).

- Calculation of the volume of electrolyte balance-affecting solutions based on physiological requirements and deficit, taking into account bolus administration of medications.

- Calculation of the volume of dextrose** and infusion rate — with total PN 24 h (starting concentration — 10% with daily concentration increases of 2.5–5%).

- Checking and, if necessary, correcting the energy (kcal) to nitrogen (g) ratio = 1:250–300. In case of insufficient energy supply per 1 g of amino acids, the amino acid dose should be reduced.

Example of compiling a PN regimen:

A 3-year-old child weighing 16 kg, second day post-surgery precluding enteral nutrition.

Daily fluid volume V = 1000 ml + 50 ml × 6 kg = 1300 ml.

Does not require transfusion therapy.

Amino acid volume: V = 16 kg × 1.5 g = 24 g,

Fat emulsion volume: V = 16 kg × 1.5 g = 24 g,

Electrolyte volume:

Potassium V = 16 kg × 2 mmol = 32 mmol = S.KCl 4% — 64.0

Sodium V = 16 kg × 2 mmol = 32 mmol = S.NaCl 10% — 37.0

Magnesium V = 16 kg × 0.1 mmol = 1.6 mmol = S.MgSO₄ 25% — 1.6

Calcium V = 16 kg × 0.2 mmol = 3.2 mmol = S.Ca gluconici 10% — 13.0

Does not require correction of electrolyte deficits.

- Volume of 10% dextrose**: V = 1300 ml — 272.0 — 120.0 — 104.0 (electrolytes) — 26.0 (bolus infusions) = 778.0 ml ~ 800.0

- Nitrogen to energy ratio. Nitrogen — 24.0 = 3.5 g, energy: amino acids 24.0 g = 216 kcal + 10% dextrose** — 800.0 = 320 kcal. Total = 536 kcal. Nitrogen to energy ratio = 1:153, which requires reducing the amino acid volume to 160 ml (ratio 1:225).

Patient prescriptions:

- Dextrose** 10% — 800.0 Infusion rate 37 ml/h

- Potassium chloride** 4% — 64.0

- Sodium chloride** 10% — 37.0

- Magnesium sulfate** 25% — 1.6

- Calcium gluconate** 10% — 13.0

- Fat emulsion for parenteral nutrition** 20% — 120.0 Infusion rate 5.8 ml/h

- Amino acids for parenteral nutrition** 10% — 160 Infusion rate 6.7 ml/h

- Amino acids for parenteral nutrition** (containing N(2)-L-alanyl-L-glutamine 32.0)

In case of prolonged (more than 7–14 days) PN, multivitamins [parenteral administration] and trace elements are added to the infusion therapy [121, 138].

Appendix A3.26 Symptoms of severe refeeding syndrome [148,175]

Appendix A3.27. ASPEN consensus criteria for identifying pediatric patients at risk for refeeding syndrome

ASPEN consensus criteria for identifying pediatric patients at risk for refeeding syndrome [148].

*ASPEN - American Society for Parenteral and Enteral Nutrition

Appendix B. Physician Action Algorithms

Not applicable.

Appendix C. Patient Information

A growing child's body requires more nutrients than an adult's.

Childhood malnutrition is a condition in which the body does not receive the necessary nutrients to fully meet its needs. To compensate for the nutrient deficit, the body begins to break down its own tissues: first fat reserves, followed by muscles, skin, hair, and nails. A malnourished child may exhibit visible wasting, growth retardation, and developmental delay.

The human body requires specific types of nutrients in appropriate amounts and forms depending on age and condition to function properly.

The main groups of nutrients include proteins, fats, and carbohydrates (so-called macronutrients). These substances provide energy and "building blocks" for the body.

In addition to macronutrients, it is vital that the child receives adequate amounts of minerals and vitamins (especially those that the human body cannot synthesize on its own). Vitamins and minerals are involved in metabolic processes.

How to recognize if a child has malnutrition?

If you notice the following in your child:

• Weight loss or low body weight

• Loss of muscle mass or fat

• Loss of appetite

• Severe fatigue or weakness

• Skin changes (dryness, laxity) and hair changes (dryness, thinning, hair loss)

• Mood changes

• Edema (which can occur due to water retention by the body)

What are the causes of malnutrition?

• Lack of nutrients in the diet due to low family income and/or insufficient knowledge about healthy nutrition

• Acute or chronic illnesses, surgeries, injuries, etc. (which reduce appetite and/or complicate food intake and/or impair food absorption and/or cause calorie loss)

• Child's food selectivity or food refusal (eating disorders)

• Negative phenomena associated with eating (nausea, pain, difficulty chewing, swallowing, etc.)

How is malnutrition diagnosed?

It can be difficult for parents to assess on their own whether a child is eating enough to grow and develop according to age.

A physician can help with this.

The physician will ask you questions and perform an examination.

Additionally, the following may be performed to assess nutritional adequacy:

• Weight measurement

• Measurement of body fat percentage

• Muscle mass measurement

• Laboratory tests to check for specific micronutrient imbalances or other issues

How is malnutrition treated?

Treatment will be prescribed by a physician depending on the cause of malnutrition and the severity of its manifestations, either at home or in a hospital setting.

As a rule, treatment of the underlying disease or condition causing the malnutrition is prescribed, a balanced diet is selected, and in addition, specialized medical nutrition products in the form of drinks, powders, etc., may be prescribed.

In some cases, nutrition may be administered via a tube (a catheter inserted through the nose into the stomach or small intestine) or a stoma (nutrition is delivered directly into the stomach/intestine through a surgically created opening).

Sometimes nutrition is administered intravenously.

The method and duration of medical nutrition are determined by the physician. It is essential to strictly follow all recommendations for successful treatment.

Is there a way to prevent undernutrition?

• It is necessary to undergo comprehensive routine preventive examinations for the child in a timely manner, starting from discharge from the maternity hospital.

• A balanced diet, adequate in volume and content, should be provided.

• Treat the underlying disease that led to the development of malnutrition.

What signs require seeing a doctor?

• Sudden weight loss

• Severe weakness, fatigue

• The child complains of tingling, numbness, and pain in the hands or feet, or bone pain (possible signs of vitamin deficiency or anemia)

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Appendix G1. Russian-language version of the STRONGkids screening tool for assessing nutritional risk in children

Russian title: Russian-language version of the STRONGkids nutritional risk screening tool for children.

Original title (if applicable): Screening Tool for Risk on Nutritional status and Growth.

Source (official developer website, validation publication): [56,57].

Type (underline): questionnaire.

Purpose: To assess the risk of malnutrition in children aged 1 month to 18 years admitted to a hospital with an expected hospital stay of more than 24 hours. The assessment is conducted within the first 24 hours of hospital admission. The nutritional risk screening questionnaire consists of 4 items; the first 2 items are completed independently by medical staff, and the next 2 items are filled out based on medical history obtained from the parents. Each item contains questions where a "yes" answer is scored 1–2 points; the maximum total score is 5. In case of doubt, the answer should be considered negative (0 points).

Content (template):

Key (interpretation):

Notes: none.