Laboratory diagnostics: typical changes
To confirm the diagnosis and assess the patient's condition, basic laboratory tests are used. Characteristic shifts are observed in both blood tests and the analysis of bronchial secretions.
Complete blood count (CBC)
- The basic and most typical sign of the disease is eosinophilia.
- During an exacerbation of the pathological process, leukocytosis and an accelerated erythrocyte sedimentation rate (ESR) are frequently recorded.
- Clinically important nuance: the detected leukocytosis is often iatrogenic. This means that an elevated white blood cell count may not only be a sign of inflammation, but also a direct consequence of systemic glucocorticosteroid intake (for example, medications based on prednisolone).
Sputum microscopy Microscopic examination of sputum reveals a cellular composition rich in eosinophils and desquamated epithelium. In addition, strictly specific elements are detected:
- Curschmann spirals — these are peculiar casts of the small airways formed entirely by thick mucus.
- Charcot-Leyden crystals — these are crystallization products of enzymes released from destroyed eosinophils.
Instrumental monitoring methods
Instrumental diagnostics are necessary to objectify the severity of obstruction and regularly monitor the state of the respiratory system.
- Peak flowmetry. This is a key method used for the early detection of obstructive syndrome and daily self-monitoring. The main measured parameter is peak expiratory flow (PEF). A strict clinical requirement states that every patient suffering from this condition must have a personal peak flow meter for individual use.
- Spirometry (assessment of pulmonary function tests — PFTs). The method provides basic indicators for an accurate assessment of the severity of the condition. First and foremost, forced expiratory volume in the first second (FEV₁) and peak expiratory flow (PEF) are analyzed. Spirometry is also actively used during specialized provocative tests aimed at detecting hyperreactivity of the bronchial tree.
Patient management and treatment strategy
The fundamental task of the physician when prescribing therapy is to ensure a normal quality of life for the patient. At the same time, a clear management logic implies the unconditional priority of non-pharmacological methods, supplemented by pharmacological support.
Non-pharmacological methods (priority direction):
- Patient education. Implemented through so-called "Asthma Schools". These programs provide detailed information about the nature of the disease and teach practical self-monitoring methods (primarily, proper peak flowmetry).
- Elimination measures. Consist in the maximum possible restriction or complete cessation of contact with known irritants and allergens.
Pharmacotherapy: Pharmacological intervention includes the use of bronchodilators and anti-inflammatory drugs. It is important to understand the logic behind their prescription: these drugs do not replace prevention, but merely serve as a necessary supplement to educational and elimination measures.
Briefly: answers to topical questions
What are the main parameters evaluated during spirometry in patients with bronchial asthma?
During spirometry in patients with bronchial asthma, basic flow and volume parameters are evaluated to determine the severity of obstruction. Key parameters include:
- FEV1 (FEV1) — forced expiratory volume in 1 second (the most important and standardized parameter).
- PEF — peak expiratory flow.
- VC (VC) — vital capacity.
- FVC (FVC) — forced vital capacity.
- Ratio indices — FEV1/FVC (Gensler index) and FEV1/VC (Tiffeneau index).
Which drug classes are classified as bronchodilators used in bronchial asthma?
Bronchodilators used in bronchial asthma include:
- Short-acting β2-agonists (SABAs) — first-line drugs for relieving exacerbations; examples: salbutamol, fenoterol.
- Long-acting β2-agonists (LABAs) — mentioned as part of combination therapy with ICS or when added to ICS.
- Anticholinergics — for example, ipratropium bromide, as alternative or combination bronchodilators.
- Combination agents — SABA + ipratropium bromide.
Which pharmacological groups are used as baseline anti-inflammatory therapy for asthma?
As baseline anti-inflammatory therapy for bronchial asthma, drugs that target the pathogenesis of the disease (infiltration and edema) are used. These include:
- Glucocorticosteroid preparations — primarily inhaled corticosteroids (ICS).
- Mast cell stabilizers — cromones.
- Antileukotriene agents — leukotriene receptor antagonists and leukotriene synthesis inhibitors (5-lipoxygenase inhibitors).
- Monoclonal antibody preparations — biological therapy (for example, antibodies to IgE or IL-5R$\alpha$).
To remember specific findings in sputum, use the mnemonic: Curschmann spirals, Eosinophils (and Epithelium), Charcot-Leyden crystals.
Class and exam questions
What specific elements are detected upon microscopy of the patient's sputum?
Sputum reveals a large number of eosinophils and epithelium, as well as specific elements: Curschmann spirals (mucus casts of small bronchi) and Charcot-Leyden crystals (crystallized eosinophil enzymes).
Why might leukocytosis be observed during an exacerbation?
Although leukocytosis and an accelerated ESR are characteristic of an exacerbation, the increase in leukocyte count is often iatrogenic in nature. It occurs as a direct consequence of taking systemic glucocorticosteroids, such as prednisolone.
What clinical requirement is placed on patients as part of self-monitoring?
The key clinical requirement is that absolutely every patient must have an individual peak flow meter for regular monitoring of peak expiratory flow (PEF).
What is the logic behind prescribing pharmacotherapy?
Priority is given to non-pharmacological measures (education in "Asthma Schools" and allergen elimination). Bronchodilators and anti-inflammatory drugs are prescribed exclusively as an adjunct to these basic preventive and educational measures.
What else to study on this topic
- Mechanism of iatrogenic leukocytosis development during glucocorticosteroid therapy
- Methodology for conducting provocative tests with spirometry
- Evaluation of FEV₁ and PEF parameters to determine the severity of obstruction
- Organization and curriculum of "Asthma Schools"
- Rules for performing peak flowmetry at home
Master the entire topic in the "Propaedeutics" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Diagnosis and Treatment of Bronchial Asthma" and 3,152 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 113 video lessons on the subject
Other topics in the "Respiratory System" section
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.