Gastric lavage, commonly known as “stomach pumping,” is a medical procedure to clean out the stomach’s contents. It involves introducing fluids and then removing them, typically to eliminate harmful substances or prepare the stomach for other medical interventions. While the term “stomach pumping” might suggest simple suction, the procedure is more nuanced, involving both irrigation and suction.
Understanding Gastric Lavage
Gastric lavage is a medical technique that flushes out stomach contents using a tube. In emergency medicine, its primary purpose is to remove ingested poisons or drug overdoses before they are fully absorbed into the bloodstream. The procedure can also serve diagnostic purposes, such as collecting stomach fluid samples for analysis, or therapeutic functions like managing gastrointestinal bleeding.
The Procedure Explained
The process typically begins by positioning the patient on their left side with their head angled downward. This positioning aims to delay gastric emptying and reduce aspiration risk. A large-bore tube, either nasogastric (through the nose) or orogastric (through the mouth), is lubricated and carefully inserted into the stomach. The orogastric route is often preferred for gastric emptying due to the larger tube size it accommodates.
Confirming the tube’s correct placement in the stomach is important to ensure it is not in the lungs. This can involve aspirating stomach contents for pH testing, listening for air insufflation, or using an X-ray. Once confirmed, small volumes of fluid, usually warm water or saline, are administered into the stomach. For adults, this typically involves 200 to 300 mL per cycle; for children, normal saline is used at 10-15 mL/kg to avoid hyponatremia.
The fluid is then drained or suctioned out, often by siphoning into a collection bucket. This wash-and-drain cycle repeats multiple times until the fluid returning from the stomach appears clear. Throughout the procedure, suction equipment is kept ready due to the possibility of vomiting and aspiration risk. If a patient is unconscious or cannot protect their airway, endotracheal intubation is performed before the lavage.
Indications for Gastric Lavage
Gastric lavage was historically used for acute poisoning or drug overdose to remove toxic substances. It is considered when a potentially life-threatening amount of a toxic substance has been ingested. For optimal effectiveness, the procedure should ideally be performed within 60 minutes of ingestion. The efficacy of removing ingested substances decreases rapidly; for instance, only about 8% of the ingestant may be recovered after 60 minutes.
While primarily associated with poisoning, gastric lavage also has other applications. It can alleviate stomach pressure caused by excess food, fluids, or air. It can also remove excess bleeding in cases of gastrointestinal hemorrhage. In some instances, it serves as a cooling measure for patients with severe hyperthermia, utilizing iced saline.
Potential Complications and Contraindications
Despite its potential benefits, gastric lavage carries various risks and complications. One serious risk is aspiration pneumonia, which occurs if stomach contents are inhaled into the lungs. This risk is heightened if the patient’s airway is unprotected, especially with certain ingested substances like hydrocarbons. Mechanical injury to the esophagus or stomach, such as perforation, is another potential complication.
Other reported complications include laryngospasm, hypoxia, and electrolyte imbalances like hyponatremia or hypochloremia. Cardiac rhythm disturbances and bradycardia can also occur. The procedure might also inadvertently push the toxic substance further into the gastrointestinal tract, potentially increasing absorption.
There are specific situations where gastric lavage should not be performed, known as contraindications. It is generally not recommended for patients with a compromised or unprotected airway, unless intubation is performed first. Ingestion of corrosive substances (strong acids or bases) or hydrocarbons is typically a contraindication due to the high risk of esophageal damage or aspiration. The procedure is also contraindicated if there is a significant risk of gastrointestinal bleeding or perforation.
Current Clinical Role
The role of gastric lavage in modern emergency medicine has significantly diminished. Its routine use for poisoning treatment is no longer recommended by many medical organizations, including the American Academy of Clinical Toxicology. This decline stems from evidence indicating limited effectiveness and substantial risks. Studies have shown that the amount of toxin removed is often unreliable and negligible, particularly if performed more than an hour after ingestion.
Alternative and often safer treatments have largely replaced gastric lavage for gastrointestinal decontamination. Activated charcoal administration is now the preferred method for many types of poisoning. Antidotes and supportive care have also become central to managing poisoned patients. While gastric lavage may still be considered in rare, specific circumstances, such as a life-threatening ingestion of a substance not adsorbed by activated charcoal, its application is limited and requires careful consideration of the risks versus potential benefits.