Within how many hours after ingestion is gastric lavage (stomach wash) beneficial?

Gastric Lavage (Stomach Wash) Time Window After Ingestion

Gastric lavage should NOT be performed routinely and, if considered at all, must be done within 60 minutes (1 hour) of ingestion for potentially life-threatening poisonings—beyond this narrow window, the procedure offers no proven benefit and carries significant risks. 1, 2

Evidence-Based Time Limitations

The 60-Minute Critical Window

• The American Academy of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists state that gastric lavage should only be considered if the procedure can be undertaken within 60 minutes of ingestion, and even then, clinical benefit has not been confirmed in controlled studies 2
• More recent Dutch guidelines suggest an even narrower window of 1-2 hours for extremely serious intoxications only 3
• After 2 hours post-ingestion, most toxins have already been absorbed or moved beyond the reach of gastric lavage, making the procedure futile 4

Why Gastric Lavage Is Generally Not Recommended

• There is no certain evidence that gastric lavage improves clinical outcomes, and it may cause significant morbidity including aspiration, esophageal perforation, and cardiac arrhythmias 1, 2
• In experimental studies, the amount of toxin removed by gastric lavage was highly variable and diminished rapidly with time 2
• Recent systematic reviews from 2003-2011 continue to show that gastric lavage may be associated with serious complications without demonstrable benefit 1

Preferred Alternative: Activated Charcoal

Extended Time Window for Activated Charcoal

• Activated charcoal can be administered up to 2 hours after ingestion and remains the preferred decontamination method 3
• For certain substances like nortriptyline, activated charcoal may produce significant reduction in absorption even when administered up to 4 hours after ingestion 5
• For paracetamol (acetaminophen) intoxication, activated charcoal is recommended within 4 hours if possible 5

When Activated Charcoal Is Preferred

• Activated charcoal should be administered as soon as possible after emergency department presentation unless the agent is known not to adsorb to charcoal or absorption is probably complete 4
• Standard dosing is 1-2 g/kg body weight orally or via nasogastric tube 6

Rare Exceptions Where Gastric Lavage Might Be Considered

Specific Clinical Scenarios (Within 60 Minutes Only)

• Life-threatening ingestions of substances in massive quantities 4, 2
• Symptomatic patients presenting in the first hour after ingestion of agents that slow gastrointestinal motility 4
• Patients taking sustained-release medications where delayed absorption may occur 4

Absolute Contraindications to Gastric Lavage

• Never perform gastric lavage if airway protective reflexes are lost unless the patient is intubated 2
• Contraindicated after ingestion of hydrocarbons with high aspiration potential or corrosive substances 2
• In paraquat poisoning with documented caustic injury, gastric lavage should NOT be performed at 6 hours post-ingestion 7

Clinical Decision Algorithm

1. Assess timing: Is it within 60 minutes of ingestion? If no, gastric lavage is not indicated 2
2. Assess severity: Is this a potentially life-threatening amount? If no, gastric lavage is not indicated 2
3. Assess airway: Are protective reflexes intact or is the patient intubated? If no, gastric lavage is contraindicated 2
4. Assess substance: Is it caustic or a hydrocarbon? If yes, gastric lavage is contraindicated 2
5. Default to activated charcoal: In nearly all cases, activated charcoal (if within 2-4 hours) is safer and equally or more effective 3, 4

Common Pitfalls to Avoid

• Do not delay activated charcoal administration to perform gastric lavage—studies show no benefit to combining both methods and increased complications including higher rates of intubation and ICU admission 4
• Do not use gastric lavage routinely—it should only be performed by individuals with proper training and expertise in the rare instances it is indicated 1
• Do not assume gastric lavage is beneficial beyond 1 hour—the evidence shows diminishing returns with time and no proven clinical benefit 2