Lavage, a term derived from the French word laver, meaning “to wash,” describes a medical procedure that involves flushing an organ, body cavity, or wound with a fluid. This technique is used to wash out unwanted material, either for therapeutic purposes, such as removing a toxic substance, or for diagnostic reasons, like collecting a sample for laboratory analysis. Lavage is a common practice in modern medicine, functioning as a direct method for both treatment and investigation across various medical specialties.
The Core Mechanism of Lavage
The principle behind lavage is a simple, two-step process of irrigation and retrieval. A specific solution, most often a sterile saline solution, is gently introduced into the target area through a tube or catheter. This fluid then mixes with the contents of the cavity, organ, or space being treated.
Once the solution has been instilled, it is then collected, either through aspiration using gentle suction or by allowing it to drain out naturally, often with the assistance of gravity. This retrieval process carries the unwanted material—such as toxins, debris, cells, or inflammatory products—out of the body or into a collection vessel. The process may be repeated until the fluid returning from the body is visibly clear, indicating a sufficient level of cleansing.
The choice of fluid is usually sterile normal saline, a solution of 0.9% sodium chloride in water that matches the salt concentration of the body’s fluids. Using saline helps prevent shifts in fluid and electrolyte balance in the surrounding tissues. In some cases, the lavage solution may be warmed to body temperature to prevent hypothermia, particularly when large volumes are used.
Lavage for Emergency Toxin Removal
One of the most recognized applications of this procedure is Gastric Lavage, commonly referred to as stomach pumping, which is performed for acute toxin removal. This emergency intervention aims to empty the stomach of unabsorbed poisons or drugs following an overdose or accidental ingestion. The procedure is time-sensitive, as its effectiveness decreases significantly the longer the substance remains in the stomach.
A large-bore tube, typically an orogastric tube, is passed through the mouth and down into the stomach. The tube’s placement must be confirmed, often by aspirating initial stomach contents or through radiography, to ensure it has not mistakenly entered the lungs. Small volumes of fluid, generally 200 to 300 milliliters of warmed saline in adults, are then sequentially instilled and immediately drained.
This cycle is repeated until the retrieved fluid, known as the effluent, appears clear of the ingested material. While once a routine measure for decontamination, the use of gastric lavage has decreased due to the risk of complications, such as aspiration pneumonia. It is now primarily reserved for life-threatening ingestions where the substance is highly toxic and the procedure can be performed within the first hour of ingestion.
Diagnostic and Sampling Applications
Lavage is frequently employed as a diagnostic tool, providing a non-surgical method to collect samples from internal organs. Bronchoalveolar Lavage (BAL) is a specialized technique used in pulmonary medicine to sample the fluid and cells from the lower respiratory tract. During a bronchoscopy, a thin, flexible tube is guided into a small segment of the lung, where a measured amount of sterile saline is introduced.
The fluid is then gently suctioned back, bringing with it cells, microorganisms, and other components from the alveolar space. Laboratory analysis of this fluid can help identify infections, such as pneumonia, or diagnose various interstitial lung diseases by examining the cellular composition. BAL provides a valuable way to assess the deep lung environment without requiring a more invasive surgical biopsy.
Another diagnostic application is Diagnostic Peritoneal Lavage (DPL), historically used in trauma care to rapidly assess for internal bleeding within the abdominal cavity. After a small incision is made, a catheter is inserted into the peritoneal space, and a quantity of warm crystalloid solution, often one liter in adults, is infused. The fluid is then drained by gravity, and the returned sample is analyzed for the presence of blood, bile, or other contents indicative of organ injury. While largely supplanted by modern imaging techniques like Focused Assessment with Sonography for Trauma (FAST) scans, DPL remains an option in settings where imaging is unavailable or in specific emergency scenarios.
Localized Cleansing Procedures
Beyond the more invasive internal procedures, lavage is also used for localized cleansing of accessible body surfaces and smaller cavities. These procedures are generally less complex and often performed for immediate decontamination or debris removal. Ocular Lavage, or eye washing, is a common example, used to flush out foreign bodies, particulate matter, or harmful chemical splashes from the eye.
A continuous stream of sterile fluid is directed over the surface of the eye to dilute and remove the contaminant, a procedure that is especially urgent in cases of chemical exposure. Wound Lavage is another routine application, involving the high-pressure irrigation of traumatic injuries or surgical sites. This flushing action removes debris, bacteria, and foreign material, thereby reducing the risk of infection and promoting better healing. Irrigation is also used in ear care for the removal of cerumen or ear wax.