Gastric lavage, commonly known as stomach pumping, is a medical procedure used in emergency settings to remove unabsorbed, toxic substances from the stomach. This technique involves introducing fluid into the stomach through a tube and then suctioning it back out to wash away ingested poisons or drug overdoses. Gastric lavage is a specialized intervention performed by trained medical professionals within a controlled environment, such as a hospital emergency department. If you suspect poisoning or a severe overdose, contact emergency services or poison control immediately. While once widely used, this form of gastrointestinal decontamination is now reserved for highly specific and time-sensitive situations due to potential risks.
Why Gastric Lavage is Performed
The purpose of gastric lavage is to remove potentially lethal amounts of toxins before they are absorbed into the bloodstream. The procedure is considered only for acute, life-threatening ingestions, such as certain drug overdoses or highly toxic chemicals. Medical toxicologists and emergency physicians make the decision to proceed by weighing the severity of the ingestion against the risks of the procedure itself.
The effectiveness of gastric lavage depends on how quickly it is performed following ingestion. Generally, the procedure is most effective if initiated within 60 minutes, as substances rapidly move from the stomach into the small intestine for absorption. For certain substances that slow stomach emptying, the window may extend slightly, but efficacy diminishes quickly after the first hour.
This technique is employed when the substance is not well bound by activated charcoal, or when the quantity ingested is so massive that mechanical removal outweighs the risks. The goal is to reduce the overall systemic dose of the poison before symptoms of severe toxicity fully manifest.
The Steps of the Clinical Procedure
Gastric lavage requires careful preparation and monitoring to ensure patient safety and maximize toxin removal. The patient is positioned in the left lateral decubitus position, lying on their left side with the head lowered about 20 degrees. This positioning helps pool stomach contents, delaying passage into the small intestine and reducing the risk of pulmonary aspiration.
A large-bore orogastric tube (typically 36 to 40 French gauge for adults) is lubricated and passed through the mouth into the stomach. The oral route is preferred over the nasal route to prevent trauma. If the patient has a decreased level of consciousness or an impaired gag reflex, endotracheal intubation must be secured before insertion to prevent aspiration of stomach contents.
Once the tube is in place, medical staff confirm its location, often by aspirating stomach fluid or using an X-ray for definitive placement. Initial stomach contents are aspirated and saved for toxicology analysis. The washing cycle, or lavage, begins by introducing measured aliquots of fluid, such as warm tap water or normal saline, into the stomach.
For adults, 200 to 300 milliliters of fluid are introduced per cycle and then immediately drained out using gravity or gentle suction. This process is repeated until the fluid returning from the stomach is visually clear, indicating that most toxic material has been removed. Activated charcoal, if indicated, may be administered through the tube before it is carefully withdrawn.
When Stomach Pumping is Not Appropriate
Gastric lavage is not appropriate for all types of poisoning and has specific contraindications. The procedure is avoided when the patient has ingested corrosive substances, such as strong acids or alkalis. Passing the rigid lavage tube through an injured esophagus can cause further damage, potentially leading to perforation.
Ingesting hydrocarbons (petroleum-based products) typically contraindicates gastric lavage due to the high risk of severe aspiration pneumonia. If these substances are regurgitated or inhaled during the procedure, they can cause a serious chemical burn and inflammatory reaction in the lungs.
If too much time has passed since the ingestion (generally exceeding one to two hours), the procedure is usually not performed because the substance will have left the stomach, rendering the lavage ineffective. Attempting the procedure after this point simply exposes the patient to the risks without the benefit of significant toxin removal. Furthermore, the procedure is not performed on patients who are unstable or severely combative, especially if intubation is not feasible, as the risk of aspiration and complications is high.