Bronchoalveolar Lavage

General Description

Bronchoalveolar lavage, or bronchoalveolar irrigation, is a diagnostic procedure that provides information about the cellular, biochemical, and microbiological components of the lower respiratory tract through aspiration and subsequent culture of a sample from the pulmonary alveoli.

When is it indicated?

One of the main indications for bronchoalveolar lavage is the diagnosis of bronchopulmonary infections, particularly opportunistic infections that affect immunocompromised patients. It also helps to identify various non-infectious lung diseases, including:

• Pneumonias
• Histiocytosis X
• Sarcoidosis
• Crohn's Disease
• Allergic bronchopulmonary aspergillosis
• Pulmonary alveolar proteinosis
• Pneumoconiosis
• Lung cancer
• Pulmonary fibrosis

Therefore, bronchoalveolar lavage may be indicated when abnormal results are obtained from a chest X-ray or CT scan, or if the patient presents symptoms of lung disease, such as persistent cough, difficulty breathing, or coughing up blood.

How is it performed?

Generally, a procedure called bronchoscopy with bronchoalveolar lavage is used. This involves the use of a thin, flexible tube with a light and camera (bronchoscope) that is inserted through the mouth or nose into the airways while images taken by the camera are displayed on a monitor.

To perform bronchoalveolar lavage, the bronchoscope is placed into one of the bronchi, and saline solution is instilled in varying amounts, usually in 20 to 50 milliliter fractions, until a total volume of between 120 and 200 milliliters is reached. After each instillation, the liquid is aspirated either manually with a syringe or through gentle mechanical suction. The aspirated liquid contains samples of cells and microorganisms from the bronchial alveoli, which are subsequently analyzed in the laboratory.

In some cases, particularly in children, due to the smaller size of their airways, a bronchoscope is not used; instead, lavage is performed directly through an endotracheal tube.

Risks

Complications during bronchoalveolar lavage are very rare and generally result from bronchoscopy:

• Fever: An inflammatory reaction may cause a rise in body temperature, but it usually resolves on its own.
• Laryngospasm or bronchospasm: The insertion of the bronchoscope can irritate and narrow the vocal cords or bronchi.
• Bleeding in the airways.
• Pneumothorax: If a lung is punctured during the procedure, air can accumulate in the pleural space, potentially causing lung collapse.
• Hypoxia: The bronchoscope may shift and obstruct ventilation, leading to a decrease in blood oxygen saturation.

What to expect from a bronchoalveolar lavage

Before the procedure begins, the patient may need to undress and wear the provided gown, and remove any removable dental devices, such as dentures. The patient's heart rate, blood pressure, and blood oxygen saturation are measured and monitored throughout the procedure.

The patient will lie on their back on the examination table, with their head slightly elevated. An intravenous sedative is administered to keep them relaxed but awake during the test. A topical anesthetic (in spray form) is applied to the nostrils, mouth, and throat. This may cause coughing, a bad taste, or the sensation of being unable to swallow or breathe, but these feelings are temporary.

Although some discomfort may be felt as the bronchoscope moves, the procedure is not painful. As the bronchoscope advances, local anesthetics are administered within the bronchi to reduce coughing. Taking deep, calm breaths can help facilitate the process. There is no pain during the instillation of the saline solution or the aspiration.

The procedure lasts between 30 and 60 minutes. Once finished, the patient must remain under observation for two to four hours before being allowed to go home. Numbness in the mouth and throat due to anesthesia is normal, and the normal reflex of coughing and swallowing may take one or two hours to return, so eating and drinking are not allowed during this time. A chest X-ray may also be performed to check for pneumothorax or other complications. It is common to experience mild sore throat, hoarseness, or cough, and to expel a small amount of blood during the 24 to 48 hours following the procedure.

Specialties in which bronchoalveolar lavage is requested

Bronchoalveolar lavage is requested in pulmonology consultations.