Bronchoalveolar Lavage (BAL)

Bronchoalveolar lavage is a procedure that collects fluid from your lungs to look for infections, cancer or other lung diseases. The fluid is collected during a bronchoscopy. A pulmonologist uses a long, thin tube (bronchoscope) to “wash” a small part of your lungs with a sterile saline (saltwater) solution.

The solution picks up cells from your body. It also collects germs that could be causing an infection, like bacteria, viruses or fungi. Your provider sends the sample to a lab to look for signs of lung diseases.

BAL can help diagnose:

• Bleeding in your lungs
• Cancer
• Infections
• Interstitial lung disease
• Pulmonary alveolar proteinosis

A healthcare provider might recommend a BAL if you have:

• Symptoms of a blockage, infection or other conditions that affect your lungs
• Imaging results that suggest a tumor, pneumonia or other changes in your lungs

How do I prepare for a bronchoalveolar lavage?

Your provider will give you instructions on how to prepare for BAL. Following their directions closely can reduce your risk of complications. Before the procedure, your healthcare provider may ask you to:

• Not eat or drink anything for eight hours before the procedure (fast)
• Not take certain medications or change your medication schedule — don’t stop taking medications unless your provider tells you to
• Ask someone to drive you home after the procedure or your hospital stay

Make sure you tell your provider about all the medications you take, including over-the-counter (OTC) and herbal supplements.

What happens during the procedure?

To get a sample from BAL during a bronchoscopy:

1. A provider inserts a needle into your arm or hand to deliver anesthesia. This will keep you asleep during the procedure.
2. You lie on a bed or table with your head propped up.
3. Your provider might spray your mouth, nose and throat with a numbing medication.
4. Once the area is numb and you’re asleep, your provider inserts the bronchoscope through your nose or mouth. Your provider moves it through your airways to your lungs.
5. When the bronchoscope is in place, your provider will release a sterile saline solution into small areas of your lungs.
6. After the fluid “washes” part of your lung, your provider will suck some of the fluid back up to collect it. They’ll send the fluid to a lab for testing.
7. Your provider will gently remove the bronchoscope.

Your healthcare team will monitor you after the procedure until you’ve recovered from anesthesia and your provider says it’s OK to go home. In most cases, it’s an outpatient procedure. This means you don’t need to stay at the hospital afterward. You can usually go home within a few hours.

What are the risks of BAL?

While the risk of complications is usually low with bronchoalveolar lavage, every procedure has some amount of risk. Complications of bronchoscopy with BAL could include:

• Bleeding
• Infection
• Irritation or inflammation of your vocal cords
• Collapsed lung (pneumothorax)

Symptoms you could experience after the procedure include:

• Increased cough
• Low-grade temperature
• Sore throat

What can I expect after a lung lavage?

Your throat may be numb for about an hour after BAL. You should avoid eating and drinking until the numbness wears off. You may have a sore throat, cough or hoarseness for a day or two afterward.

Your healthcare team will let you know when you should expect test results and if you need to schedule a follow-up appointment.

What are normal results of bronchoalveolar lavage?

Typical results for samples taken during bronchoalveolar lavage include:

Normal test results can depend on the lab performing the test. Be sure to check the normal reference range on your results.

Your results may also note whether there are signs of infection or malignancy (cancer).

When should I call my doctor?

Reach out to your provider if you have any questions about the test or its results. Call your provider right away if you have new or concerning symptoms after a BAL. These could include:

• High fever
• Shortness of breath
• Severe cough