Общеклиническое исследование мокроты

General sputum analysis (sputum examination, sputum microscopy) assesses secretions from the lower respiratory tract to characterize airway and pulmonary disease. The test supports diagnosis by describing macroscopic features and microscopic elements of sputum and helps distinguish the nature of the underlying process. It is also used to track disease activity in chronic airway disorders and to gauge response to therapy over time.

Sputum is a pathological secretion from the lower airways—trachea, bronchi, and lungs—expelled by coughing. In healthy individuals, visible sputum is not produced. Under normal conditions, the large bronchi and trachea generate up to 100 mL of tracheobronchial mucus daily, which is swallowed. This mucus contains glycoproteins, immunoglobulins, bactericidal proteins, macrophages, lymphocytes, and exfoliated bronchial epithelial cells, and it contributes to particle clearance and airway defense. Mucus production increases with disease of the trachea, bronchi, or lungs, and smokers may produce excessive secretions even in the absence of overt respiratory illness. The clinical sputum analysis documents quantity, color, odor, character and consistency, visible admixtures, cellular content, fibers, and the presence of microorganisms (bacteria, fungi) or parasites. Sputum may contain mucus, pus, serous fluid, blood, or fibrin, alone or in combination. Pus represents leukocyte aggregates at sites of inflammation; serous fluid reflects exudation; blood appears with capillary wall injury or vascular damage. Microscopy permits identification of formed elements at high magnification. Absence of pathogens on smear does not exclude infection; when bacterial infection is suspected, culture with antimicrobial susceptibility testing is recommended in parallel. Specimens are collected in a sterile, disposable container. The sample must be true sputum from the lower respiratory tract rather than saliva or nasopharyngeal secretions. Collection is performed in the morning before food intake, after thorough mouth and throat rinsing and tooth brushing. Interpretation of results requires correlation with the clinical presentation, physical examination, and findings from other laboratory and imaging studies.