Gastric Lavage Indications in Poisoning
Gastric lavage should NOT be performed routinely and is only considered in extremely rare circumstances: specifically, when a patient has ingested a potentially life-threatening amount of poison within 1 hour (maximum 2 hours), has a protected airway, and has NOT ingested caustic substances or hydrocarbons. 1, 2, 3
When Gastric Lavage May Be Considered
Specific Poisonings with Potential Indication
Mushroom poisoning (Amanita phalloides): Gastric lavage with activated charcoal via nasogastric tube may be performed if the patient presents early enough (within hours) with severe gastrointestinal symptoms following ingestion. 4
Lithium poisoning: The FDA label for lithium specifically lists gastric lavage as part of treatment for severe lithium toxicity, alongside correction of fluid/electrolyte imbalance and regulation of kidney function. 5
Massive life-threatening ingestions: Only when the substance was ingested less than 1-2 hours previously and the amount is potentially fatal. 3
Critical Timing Requirements
Within 60 minutes of ingestion is the standard recommendation, though some sources extend this to 2 hours for extremely serious intoxications. 1, 2, 3
Experimental studies show that the amount of toxin removed by gastric lavage diminishes rapidly with time, making delayed lavage essentially futile. 1
Absolute Contraindications
Never Perform Gastric Lavage When:
Caustic substances ingested (acids, alkalis, bleaching powder, batteries): Gastric lavage is absolutely contraindicated as it causes re-exposure of the esophagus to the caustic agent and increases risk of perforation. 6, 1
Hydrocarbons with high aspiration potential: Risk of aspiration pneumonitis makes lavage extremely dangerous. 1
Unprotected airway: Unless the patient is intubated, gastric lavage is contraindicated if airway protective reflexes are lost. 1
Evidence of perforation or transmural necrosis: Radiological signs of perforation make any gastric manipulation dangerous. 6
Why Gastric Lavage Is Rarely Indicated
Evidence Against Routine Use
No proven clinical benefit: There is no certain evidence that gastric lavage improves clinical outcomes in poisoned patients. 1, 2
Significant morbidity risk: Recent publications continue to show that gastric lavage may be associated with serious complications including cardiac arrest, aspiration of fluid, and death. 2, 7
Variable efficacy: The amount of marker removed in experimental studies was highly variable and often minimal. 1
Preferred Alternative: Activated Charcoal
Activated charcoal is the preferred method of gastrointestinal decontamination and should be administered up to 2 hours after ingestion (up to 3-4 hours for acetaminophen). 4, 3
For acetaminophen poisoning specifically, activated charcoal (1 g/kg orally) should be given just prior to N-acetylcysteine administration if ingestion occurred within 4 hours. 4
Multiple-dose activated charcoal (15-20 g every 6 hours) may enhance elimination of specific toxins including phenobarbital, carbamazepine, theophylline, dapsone, and quinine—but only after airway protection. 4, 8, 3
Critical Caveats
Resource-poor settings: Observational studies from developing countries show that gastric lavage as routinely performed (without proper airway protection, using excessive fluid volumes, without monitoring) is extremely hazardous and likely causes more harm than benefit. 7
Consent and sedation: If lavage is deemed necessary, it should only be performed in patients who give verbal consent OR who are sedated and intubated. 7
Do NOT induce vomiting: Induced emesis is absolutely contraindicated in all poisonings as it causes re-exposure and increases aspiration risk. 6, 9