Resuscitation and Intensive Care
If the infant fails to restore cardiac activity after birth or if bradycardia persists, intravenous or intracardiac administration of a 0.1% epinephrine (adrenaline) solution at a dose of 0.1 mg/kg of body weight is indicated.
Resuscitation is considered successful when the newborn develops adequate spontaneous breathing, heart rate normalizes, and skin turns pink. However, if heartbeat fails to appear within 20 minutes despite full resuscitative measures, death is pronounced.
Following a successful first stage in the delivery room, the infant is transferred to the intensive care unit (ICU). If the newborn presents with shock, cyanosis, seizures, or is unable to breathe adequately on their own, transportation is carried out with ongoing mechanical ventilation.
For moderate to severe asphyxia, the treatment regimen includes head-cooling (selective head cooling), as the brain is extremely sensitive to oxygen deficiency. However, this method has strict contraindications:
- prematurity;
- body weight less than 1,800 g;
- massive intracranial hemorrhage.
Degrees of post-hypoxic CNS injury
Oxygen deprivation inevitably affects the nervous system, causing hypoxic-ischemic and hypoxic-hemorrhagic lesions. The severity of symptoms depends on the severity of the sustained asphyxia:
- Mild injuries. Manifest with mild and inconstant symptoms. The main clinical sign is increased neuro-reflex excitability.
- Moderate injuries. Focal lesions are usually absent, but either general depression syndrome (poor sucking, frequent regurgitation, decreased or asymmetric muscle tone, extinction of unconditioned reflexes) or hypertension syndrome dominates. The latter is characterized by fontanelle bulging, fine-amplitude tremor, motor restlessness, short-term clonic seizures, and specific ocular signs (horizontal nystagmus, Graefe's sign, and setting-sun sign).
- Severe injuries. Occur against the background of hypoxemic shock and an Apgar score of ≤ 3 points. Caused by generalized brain edema or intracranial hemorrhage. The infant is in a coma, lethargic, and emits a weak moan. Frequent seizures with a predominance of the tonic component, focal symptoms, and persistent respiratory and hemodynamic disorders are characteristic.
Specific brain injuries: IVH and PVL
In premature infants, hypoxia most commonly leads to two severe pathologies that may remain asymptomatic in the first days of life. Therefore, neurosonography is the primary diagnostic method.
Peri- and intraventricular hemorrhage (IVH) Usually occurs in the first 4 days of life. The primary source is the subependymal germinal matrix, an aggregation zone of cerebral neuroblasts. Subsequently, blood may fill the entire ventricular system, and cysts frequently form at the site of the lesion.
Ultrasound grading distinguishes 4 degrees of IVH severity:
- Grade I — isolated subependymal hemorrhage.
- Grade II — blood in the ventricles without ventricular dilatation.
- Grade III — hemorrhage with ventricular dilatation.
- Grade IV — ventriculomegaly with breakthrough of blood beyond the ventricles into the brain parenchyma.
Periventricular leukomalacia (PVL) This is a bilateral ischemic infarction of the white matter adjacent to the lateral ventricles. It is triggered by a drop in mean arterial pressure below 30 mmHg, bradycardia, acidosis, and hypovolemia. In the neonatal period, PVL manifests as general depression and hypotonia (predominantly in the legs). Ultrasound reveals focal lesions that turn into multiple cysts within 1–2 weeks. In the future, this threatens the development of spastic diplegia, visual impairment, and intellectual disability.
Birth injuries associated with hypoxia
Acute and chronic hypoxia makes fetal tissues (especially premature ones) more vulnerable, significantly increasing the risk of mechanical injury during passage through the birth canal.
Birth injuries can affect bones, soft tissues, or the central or peripheral nervous system. The main causes of trauma include:
- precipitate, rapid, or conversely, prolonged labor;
- fetal macrosomia or maternal pelvic disproportion;
- use of operative vaginal delivery (obstetric forceps, vacuum extraction, internal podalic version).
Briefly: answers to topical questions
What are the stages of fetal hypoxia according to cardiotocography (CTG)?
Cardiotocography distinguishes initial and pronounced stages of fetal hypoxia.
- Initial signs — characterized by moderate tachycardia (baseline FHR increase to 170–190 bpm) or bradycardia (down to 100 bpm), decreased rhythm variability, periodic short-term arrhythmia, and monotony.
- Pronounced signs — manifest as tachycardia over 200 bpm or bradycardia below 80 bpm, persistent rhythm monotony (decreased frequency and amplitude of instantaneous oscillations), reactive non-stress test failure (decelerations in response to movement), and prolonged late FHR decelerations.
Which biochemical markers in umbilical cord blood indicate acute fetal hypoxia?
To diagnose fetal hypoxia, acid-base balance and umbilical cord blood gas parameters are evaluated:
- pH;
- buffer bases (base deficit or acid excess, BE);
- partial pressure of carbon dioxide ($pCO_2$);
- partial pressure of oxygen ($pO_2$);
- lactate level.
What are the methods for antenatal diagnosis of chronic fetal hypoxia?
Antenatal diagnosis of chronic fetal hypoxia is based on assessing its functional state using additional instrumental and laboratory methods. The main methods include:
- Cardiotocography — assessment of fetal heart rate;
- Sonography — ultrasound examination;
- Dopplerometry — assessment of blood flow in the mother-placenta-fetus system (allows diagnosing hypoxia earlier than CTG);
- Biophysical profile of the fetus — combined result of ultrasound and CTG monitoring;
- Cordocentesis — obtaining umbilical cord blood to assess acid-base status;
- Amniocentesis — obtaining amniotic fluid (indicated for chronic hypoxia).
It is easy to remember the 4 degrees of intraventricular hemorrhage (IVH) by increasing volume: I — lesion only (subependymal), II — in the ventricles (without dilatation), III — ventricular dilatation, IV — extension into the brain tissue (parenchyma).
Class and exam questions
When should neonatal resuscitation in the delivery room be discontinued?
Measures are discontinued upon successful restoration of adequate breathing, normalization of heart rate, and skin color. If no pulse is present for 20 minutes despite adequate resuscitation, death is pronounced.
Who is contraindicationed for head cooling (selective head hypothermia)?
It is contraindicated in premature infants, newborns with a body weight of less than 1,800 g, and in the presence of massive intracranial hemorrhages.
Why is it difficult to detect intraventricular hemorrhage clinically in the first days of life?
In extremely premature infants during the first hours and days, neurological symptoms are often subtle or absent, making neurosonography critical for diagnosis.
What else to study on this topic
- Pathogenesis of periventricular leukomalacia development
- Mechanisms of cyst formation following intraventricular hemorrhage
- Specifics of neonatal intensive care in the ICU
- Classification and types of birth injuries (CNS, bones, soft tissues)
- Apgar score evaluation of the newborn in severe asphyxia
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