“Lung washing,” or lung lavage, describes medical procedures that involve rinsing the airways and air sacs of the lungs with a sterile fluid. This technique serves two main purposes: diagnostic (collecting samples for analysis) or therapeutic (clearing out accumulated substances). The fluid, typically sterile saline, is introduced and then retrieved to gather cells, proteins, and debris from deep within the lungs. This procedure helps medical professionals gain insights into respiratory problems or actively treat certain lung conditions.
Distinguishing the Two Main Types
The phrase “lung washing” encompasses two distinct procedures that differ significantly in scale and purpose: Bronchoalveolar Lavage (BAL) and Whole Lung Lavage (WLL). BAL is the more common, minimally invasive diagnostic approach. It is performed on a small, localized area, typically sampling only about three percent of the total alveolar volume. WLL, in contrast, is a large-scale therapeutic procedure that addresses an entire lung, one side at a time. This method involves instilling and removing a massive volume of fluid, sometimes up to 20 to 50 liters per lung, to physically clear the organ of obstructing material.
Step-by-Step Procedure Mechanics
For Bronchoalveolar Lavage, preparation includes local anesthesia to the throat and moderate sedation to suppress the cough reflex. A thin, flexible bronchoscope with a camera is inserted through the nose or mouth and guided into the airways. The physician maneuvers the bronchoscope until it is “wedged” into a smaller airway, isolating a specific lung segment.
A measured amount of warm, sterile saline solution (usually 50 to 60 milliliter aliquots) is pushed through the bronchoscope channel into the targeted segment. The fluid mixes briefly with the contents of the air sacs before being immediately retrieved using gentle suction. The retrieved fluid, called Bronchoalveolar Lavage Fluid (BALF), is collected and sent for laboratory analysis.
Whole Lung Lavage requires general anesthesia and a specialized double-lumen endotracheal tube. This tube ensures one lung can continue to be ventilated while the other is completely isolated and filled with warm saline. The fluid is instilled by gravity in one-liter aliquots, often with a physical therapist performing chest percussion to help dislodge the material.
The therapeutic endpoint is reached when the cloudy, milky fluid initially drained becomes clear. The process of filling and draining is repeated many times using large volumes of saline. After the lung is re-expanded, the procedure is typically repeated on the opposite side in a separate session a few weeks later.
Medical Conditions Requiring Lung Washing
Lung washing procedures are indicated for a wide array of conditions, serving as either a diagnostic tool or a direct treatment. Bronchoalveolar Lavage is utilized to diagnose infections by identifying pathogens like bacteria, viruses, or fungi in the retrieved fluid. It also helps assess interstitial lung diseases, such as sarcoidosis or hypersensitivity pneumonitis, by analyzing the type and proportion of inflammatory cells present.
The fluid collected from a BAL can also be examined for malignant cells to diagnose lung cancer, or for signs of alveolar hemorrhage. Whole Lung Lavage is primarily a treatment for a specific, rare condition called Pulmonary Alveolar Proteinosis (PAP).
In PAP, a buildup of protein and lipid material, derived from lung surfactant, clogs the air sacs and severely impairs gas exchange. WLL physically removes this accumulated material, which improves a patient’s breathing and oxygen levels. Therapeutic lavage has also been explored to remove inhaled substances like mineral dust in silicosis or meconium in newborns.
Patient Experience and Safety Considerations
Following Bronchoalveolar Lavage, patients have a short recovery period and may be monitored for a few hours before going home. Common side effects include a temporary sore throat from the bronchoscope and a mild fever. A mild drop in blood oxygen levels is the most significant side effect, but it is closely monitored by the medical team.
Recovery from Whole Lung Lavage is more involved, often requiring a one-night hospital stay for observation after general anesthesia. Patients may cough frequently as the lungs continue to clear residual fluid and debris. Serious complications from either procedure are uncommon but include bleeding, infection, and pneumothorax.