Bronchoalveolar lavage

Bronchoalveolar lavage (abbreviated as BAL) is a therapeutic and diagnostic procedure during which, during bronchoscopy, the bronchopulmonary tree is washed with saline, the lavage medium is aspirated and its composition is examined.

Bronchoscopy is a diagnostic procedure in which the bronchoscope tube is inserted into the trachea, the trachea and main bronchi are examined, their condition, degree and nature of inflammatory changes are assessed. Then the bronchi on the side of the lesion are examined and their contents are aspirated. Manipulation is carried out in order to detect interstitial lung diseases (chronic lung tissue diseases or alveolitis).

Historical background

At the beginning of the 1922th century, during the treatment of pneumonia, an experimental procedure was first performed – bronchial lavage to remove inflammatory fluid from them. In a hospital setting, bronchoscopy was first performed in 38. After XNUMX years, bronchial lavage was performed using an endotracheal tube, further probes with two lumens were used.

The classical method of carrying out bronchoalveolar lavage has been used since the mid-90s to identify the nature and characteristics of the course of pulmonary diseases.

During the procedure, the doctor washes the bronchoalveolar region with a special solution (most often sodium chloride is used).

During the procedure, it is possible to obtain bronchial secretions and cells from deeply localized segments of the lungs. The technique is constantly being improved and new methods of bronchoalveolar lavage procedure are proposed for clinical purposes and fundamental diagnostics.

Execution of the study

Bronchoalveolar lavage involves the introduction into the bronchial cavity during bronchoscopy of a lavage medium in a volume of 100 to 300 ml, which is necessary to dilute bronchial secretions and reduce its viscosity. The bronchi are washed with liquid and in parallel there is a continuous aspiration of bronchial secretions. The resulting sputum is sent to the laboratory for appropriate analysis.

BAL is recommended for detection of infection, inflammatory process, pathology, anomaly, development of the tumor process. It is also advisable to carry out manipulation to assess the severity of the disease. As a result of the study, cellular damage is revealed in various lung diseases.

Washing of the tracheobronchial tree can be used as a therapeutic procedure, which is carried out with a mixture of physiological sodium chloride solution with various antibacterial and mucolytic drugs.

Indications and contraindications for BAL

The study is assigned to patients in whom diffuse or focal changes in the lungs were detected on a chest x-ray. Indications for manipulation:

• pneumonia, bronchiolitis;
• pulmonitis;
• disseminated tuberculosis;
• alveolar proteinosis;
• collagenosis;
• sarcoidosis;
• bronchial asthma;
• carcinomatous lymphangitis.

Often bronchoalveolar lavage is performed for the treatment of diseases: lipoid pneumonia, alveolar microlithiasis and cystofibrosis. Changes in the bronchi can be infectious, non-infectious, inflammatory and malignant. When aspirating lavage fluid, there is a high probability of detecting pathological disorders.

In lung diseases, alveoli, interstitium and small bronchioles almost always suffer, so bronchoalveolar lavage will help to find out their condition and see cell damage. Diagnosis is contraindicated in patients who:

• problems with the heart and blood vessels;
• respiratory failure;
• dyspnea;
• pulmonary edema;
• allergic reactions occur.

If you feel unwell before the procedure: complaints of weakness, dizziness, fatigue, heart palpitations and other symptoms should be reported to the doctor.

Bronchoalveolar lavage technique

The specialist examines the bronchi, after which the bronchoscope is inserted into the subsegmental or segmental bronchus. Flushing of the corresponding segments starts. If the patient has a diffuse disease, then the solution is injected into the reed segments or bronchi of the middle lobe of the lung. When washing the lower lobe, it is possible to obtain a larger amount of sputum and its components.

For a classic study, the bronchoscope is inserted to the mouth of the bronchus.

Sodium chloride or another medicinal solution is heated to a temperature of 36-37 ° C. A polyethylene catheter is passed through the biopsy channel of the bronchoscope and physiological saline is injected through it into the lumen of the segmental bronchus, which is then completely aspirated. The resulting portion of the liquid is a bronchial lavage. Then the catheter is advanced 6–7 cm deep into the segmental bronchus and portions of saline are fractionally injected, which are completely aspirated each time. These mixed portions make up the bronchoalveolar lavage, which is collected in a special container. The resulting lavage fluid cannot be stored in a glass container, since macrophages adhere to the glass and the test results will be distorted.

On average, the doctor injects 30-60 ml of solution 2-3 times. The maximum volume of fluid that is injected should not exceed 300 ml.

The bronchial wash is sent to a laboratory for testing, where it is centrifuged to obtain a pellet, from which swabs are prepared. The obtained samples after the necessary preparation are examined microscopically. In a smear, the number of viable cells and a cytogram are counted, which includes:

• eosinophil;
• lymphocytes;
• neutrophils;
• macrophages and other cells.

It is not recommended to take sputum from a destructive focus, since it contains elements of tissue decay, many neutrophils, intracellular components and cellular debris. In this regard, the study requires a washout located in the segments of the lungs that are adjacent to the destruction. If the resulting fluid contains more than five percent of the epithelium, it makes no sense to diagnose it, since these are cells obtained not from the bronchoalveolar space, but from the bronchial cavity.

BAL is a simple, non-invasive and well-tolerated examination technique. Thanks to the BAL technique, it became possible to use a whole range of cytological, bacteriological, immunological, and biochemical methods. These studies contribute to the correct diagnosis of oncological diseases and disseminated processes in the lungs, and also allow us to assess the activity of the inflammatory process in the bronchoalveolar space.

Possible complications

Although the procedure is considered safe and painless, complications may occur due to the volume of solution administered and its temperature. During the manipulation, patients occasionally experience a strong cough, and after diagnosis, after 3-4 hours, an increase in body temperature is observed. Complications and side effects according to statistical indicators after bronchoalveolar lavage are reported in 3% of patients, after transbronchial biopsy – in 7%, and after open lung biopsy are observed in 13%.

The effectiveness of diagnostics

To assess the condition of the lower respiratory tract, many techniques are used in clinical practice, among which the biopsy is considered the most expensive. Lavage is characterized by high efficiency of the obtained results, low risk of adverse reactions and complications.

To make an accurate diagnosis, a sample must be taken from the site that is involved in the pathological process.

Quite often, due to infections, inflammation and bleeding, a specialist cannot timely identify the underlying disease. When large volumes of lavage fluid are obtained, their significance and the likelihood of detecting disorders in the organ potentially increase.

Recovery period after bronchoscopy

After the examination, the patient needs more oxygen, so it is supplied through the endotracheal tube for 10-15 minutes. This manipulation is done in order to open the collapsed alveoli. At this time, the patient should not move and lie still, at the end of the procedure, the patient should be under observation for another 15-20 minutes.

In the case of anesthesia, after the patient wakes up, it is desirable to immediately stop the oxygen supply – the endotracheal tube is removed. If the patient does not wake up after additional oxygen is given, this indicates a pneumothorax or bronchospasm. Bronchospasm should be controlled with bronchodilators. Rupture of lung cells or damage to the trachea can provoke the development of pneumothorax. After diagnosis, after 2-3 days, doctors recommend taking an x-ray, which will show the presence of fluid in the lungs.

Within a week after the procedure, the patient should adhere to gentle bed rest. Eight hours of sleep and a balanced diet will help restore the condition and avoid complications.

Bronchoalveolar lavage is a bronchoscopic method for obtaining fluid from the bronchioles and alveoli. The sample taken is sent for further cytological, biochemical, immunological and microbiological analyses. The results obtained allow the doctor to make an accurate diagnosis and begin an effective course of therapy.

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