Sputum analysis. Main criteria and pathological changes

Sputum analysis is a method of studying the physical, quantitative and qualitative properties of bronchial and lung secretions. It enables bacteriological and cytological examination of sputum, which helps to assess the state of respiratory organs and to detect certain diseases.

In addition, this examination helps to determine the stage and nature of the pathological process in the lungs, which contributes to more correct diagnosis. It should be noted that a general analysis of sputum is one of the important studies in the pathology of respiratory organs, which allows not only to diagnose diseases, but also to determine their etiology.

Features of sputum collection

Sputum should be collected in the morning on an empty stomach, after cleaning your teeth and rinsing your mouth with boiled water. To make sputum better, on the eve of the study the patient needs to drink plenty of fluids, and before collecting the secret from the respiratory tract should take a few deep breaths, and then vigorously cough. Spitting pathological secret should be immediately in a sterile sealed vial of single use.

In cases where sputum sampling is problematic (for example, with a dry cough), a special saline solution is inhaled. If the cough is provoked by this method, then before the sputum is taken, the patient should spit the excess saliva into a special container with the saline solution.

Sputum analysis: norm and pathology

When evaluating a secret, the following criteria are taken into account:

1. The amount of sputum. Normally, sputum is released in the form of small spittles (as a protective reaction). At a pathology its quantity increases. So, with chronic bronchitis, up to 250 ml of secretion is secreted per day, and with bronchiectasis or, for example, with pulmonary abscesses, its amount can reach 500 ml per day.

2. Nature, color and consistency. Normally, mucus from the respiratory tract is transparent, and if it becomes turbid, it means that the inflammatory process is developing. There are cases when the mucus is transparent, but has a viscous consistency. This is in most cases observed in acute and some chronic diseases of the respiratory system.

If sputum analysis is performed and its yellow or green color is detected, this indicates the accumulation of pus in the lungs. If the sputum becomes amber-orange, this indicates a pronounced allergic process in the body.

With the admixture of blood, sputum becomes rusty. It should be noted that even with the appearance of minor veins of blood, you should always consult a doctor to exclude severe lung pathologies.

3. Smell of sputum and its reaction. Normally sputum should not have a smell, if it appears, it indicates the disintegration of tissues and protein compounds in the respiratory system. The secretion reaction should be alkaline, but with prolonged standing of the sputum in the respiratory system and with the impurities of the gastric juice, it becomes acidic.

Sputum analysis also includes microscopy, bacterioscopy and subsequent culture on the nutrient medium. In some diseases, there may be:

• Kurshman spirals - evidence of spasm in the airways;

• Charcot-Leiden crystals - talk about allergies, often found in bronchial asthma;

• Formed blood elements - leukocytes are found in inflammation, eosinophils - in allergies and helminthic invasion, erythrocytes - with destruction of lung tissue;

• epithelial cells and alveolar macrophages, which speak of lesions in the lower parts of the respiratory system;

• Elastic fibers - can confirm lung cancer;

• eggs of various worms that are not normally found.

Bacterioscopy is conducted to identify the causative agent of the disease. Normally sputum contains only Neisseria, alpha-hemolytic streptococci and diphtheria.