Pneumonia is an acute disease involving the respiratory parts of the lung, which occurs independently or as a complication of the underlying ailment. Inflammation of the lungs is caused by bacteria, viruses, fungi. Tests for pneumonia can determine the severity and etiology of the course of the disease.
Indications for examination
Screening for pneumonia is prescribed under certain conditions. Diagnostic criteria for the development of pneumonia are:
- history data;
- clinical examination results: fever (an increase in temperature may not always indicate the severity of the disease), manifestations of intoxication, cough, respiratory failure;
- listening with a stethophonendoscope: crepitus and rales of various sizes are heard;
- with percussion (percussion) of the pulmonary fields, a dullness of the percussion sound is observed;
- metabolic or mixed acidosis (set as a result of the interpretation of the study on the acid-base state).
To confirm the diagnosis, an X-ray examination of the chest organs is used (focal infiltrates are detected). Laboratory tests help to determine the severity of the course of the disease and the effectiveness of antibiotic therapy, but are not the leading ones in making the diagnosis.
Types of analyzes
If pneumonia is suspected, there is a specific examination plan, which consists of:
- X-ray examination in two projections (certain types of pathogens have their own picture in the picture);
- general blood test;
- general urine analysis;
- biochemical blood test, in which special attention is paid to indicators of an acute phase reaction;
- virological and bacteriological research;
- bacterioscopy.
In infants and newborns, attention should be paid to the results of a study of the prothrombin index, acid-base state and electrolytes. Adult patients need to determine these indicators only in case of a severe, protracted course of the disease or the development of complications. These analyzes are one of the main ones in the conditions of the intensive care unit.
What indicators indicate pneumonia
In a general blood test for pneumonia, the following are found:
- leukocytosis (in the case of a viral etiology of pneumonia, the level of leukocytes may be normal or reduced);
- shift of the leukocyte formula to the left (indicates an increase in the number of young forms of neutrophils);
- erythrocyte sedimentation rate is higher than normal values (15 mm / h for women and 10 mm / h for men);
- relative lymphocytosis indicates the pathogenic microflora that caused the pneumonia.
When decoding, it should be borne in mind that an increase in the number of lymphocytes is the norm for children 4-5 years old before the period of the physiological intersection of the leukocyte formula. By the extent to which these indicators are increased, one can judge the severity of the course of the pathological process.
In elderly people, the leukocyte formula may not reflect the severity of the condition due to a decrease in the reactivity of the body. With mycoplasma pneumonia, leukopenia is combined with a high ESR. The relative content of granulocytes (basophils and eosinophils) and agranulocytes (monocytes) decreases (if the inflammation is of a non-allergic or parasitic nature). 90% of cases of pneumonia are of bacterial etiology.
In a child, such changes in the blood can be the result of vaccinations and teething. In infants, there is a reaction to a change in nutrition (when introducing the first complementary food).
In a biochemical blood test, attention should be paid to acute phase indicators (C-reactive protein, fibrinogen, seromucoid, ceruloplasmin). In this analysis, you can monitor the condition of not only the lungs, but also other organs of the human body.
When examining the acid-base state, pH values, standard bicarbonates and buffering bases are important. They will directly depend on the severity of the patient’s condition with pneumonia.
observation, because it helps to monitor the condition of the kidneys. Albuminuria may occur, and in some cases, erythrocyturia and cylindruria. Excretion of chlorides by the kidneys decreases.
In a serious condition of the patient, tests must be taken at any time of the day, but for their best interpretation, it is worth taking in the morning on an empty stomach.
Elderly people have problems with the interpretation of tests and the clinical picture due to their worn out.
Laboratory criteria for severe community-acquired pneumonia:
- complete blood count: anemia (hemoglobin level below 90 g / l), thrombocytopenia (less than 150×109 / l), decrease in hematocrit below 30%;
- biochemical blood test: blood urea level is above 10 mmol / l, glucose is above 14 mmol / l;
- study of the acid-base state: hypoxemia (oxygenation index less than 250 mm Hg), acidosis (pH less than 7.35);
- study of electrolyte levels (sodium level less than 130 mmol / l).
If the patient’s condition has not improved after the prescribed therapy, and on the roentgenogram there are foci of localization atypical for community-acquired pneumonia, then SARS can be suspected.
There is a low-symptom (latent) type of pneumonia, when, against the background of the treatment of an acute respiratory infection, the patient has symptoms of intoxication. In this case, X-ray examination can confirm the development of pneumonia. If an atypical course of pneumonia is suspected and if there is a high risk of complications, complex immunological, serological and virological methods are used.
Sputum examination helps to identify the etiology of the inflammatory process. With a large number of eosinophils, pneumonia is of an allergic or parasitic nature, with tuberculosis, mycobacterium tuberculosis is found in sputum, and with mycotic lesions, micelles of fungi and the absence of pyogenic flora.
With bacterioscopy, a smear of bronchial secretion is stained according to Gram to determine the prevailing flora (gram-positive or gram-negative), which helps in choosing a therapy for pneumonia.
In young children, sputum is not examined, since they do not know how to cough it up.
In conditions of a protracted course of pneumonia or the development of severe complications, the immunological reactivity of the body is investigated. If the tests reveal abnormalities, then immunomodulatory therapy is required.
If, during laboratory tests, changes of an inflammatory nature are found, you should consult a doctor in order to exclude the development of pneumonia and prescribe the correct treatment. The course of the disease in a teenager and an adult does not differ.
As a prophylaxis of diseases, every once a year you need to be examined and tested. The interpretation of the results should be carried out by a specialist; you should not diagnose yourself on your own.