How should gastric lavage be performed on a hemodynamically stable patient who ingested a potentially life‑threatening substance within the past hour and has no contraindications?

Gastric Lavage Technique and Indications

Critical Recommendation

Gastric lavage should NOT be performed routinely and is only indicated in rare circumstances: specifically, when a hemodynamically stable patient presents within 1 hour of ingesting a potentially life-threatening substance, has no contraindications, and activated charcoal alone is deemed insufficient. 1

Absolute Contraindications

Gastric lavage is contraindicated in the following situations and should never be attempted:

• Petroleum distillates (engine oil, petrol): Risk of severe chemical pneumonitis if aspirated during the procedure 2
• Caustic ingestions (acids/alkalis): Risk of esophageal perforation and worsening tissue injury 3, 4
• Insignificant ingestions: When the amount ingested poses minimal risk 4
• Prolonged time since ingestion: Beyond 1 hour, efficacy drops dramatically 5, 1
• Unprotected airway in obtunded patients: Must intubate first 4

When Gastric Lavage May Be Considered

The procedure should only be performed in highly selected cases meeting ALL of the following criteria:

• Presentation within 1 hour of ingestion 5, 1
• Potentially life-threatening amount of toxin ingested 6, 1
• Patient is hemodynamically stable 1
• Substance forms concretions or cannot be adequately managed with activated charcoal alone 4
• Performed only by individuals with proper training and expertise 1

Proper Technique

Pre-Procedure Preparation

• Airway protection is paramount: Intubate patients with altered mental status, obtundation, or seizures before attempting lavage 4
• Position patient in left lateral decubitus position with head down 15-20 degrees to prevent aspiration 6
• Use a large-bore orogastric tube (36-40 French in adults; appropriate pediatric sizing in children) - small nasogastric tubes are nonproductive 7

Lavage Procedure

• Insert the orogastric tube and confirm gastric placement 6
• Instill 200-300 mL aliquots of warm normal saline (or room temperature water) in adults 4
• Use 10 mL/kg aliquots (maximum 200 mL) in pediatric patients 6
• Allow fluid to drain by gravity or gentle aspiration 4
• Continue until return fluid is clear, typically requiring 2-10 liters total 4
• Strict attention to technique is essential to minimize complications 6

Post-Lavage Management

• Administer activated charcoal (1 g/kg) through the lavage tube after the procedure is complete 8, 4
• Follow with a cathartic (preferably sorbitol) 5, 7
• Remove the tube after charcoal administration 4

Specific Clinical Scenarios

Acetaminophen Overdose

• If presentation is within 1 hour, gastric lavage may be considered, though activated charcoal is preferred and equally effective 8
• Activated charcoal does not reduce N-acetylcysteine effectiveness even when given immediately before the antidote 8

Mushroom Poisoning (Amanita phalloides)

• Gastric lavage via nasogastric tube may be beneficial if severe GI symptoms are present early after ingestion 8
• Must be combined with activated charcoal, fluid resuscitation, and specific antidotes (penicillin G, silibinin) 8

Complications to Monitor

Gastric lavage carries serious potential complications:

• Aspiration pneumonitis (most serious) 4, 1
• Esophageal perforation 4, 1
• Tracheal intubation (tube misplacement) 4
• Nasal trauma (if nasogastric approach used) 4
• Electrolyte imbalance and hypothermia with large-volume lavage 4

Evidence-Based Alternative

Activated charcoal alone is superior to gastric lavage for most poisonings and should be the first-line gastrointestinal decontamination method when indicated 5, 7. Recent evidence shows no benefit of routine gastric lavage, and the procedure is associated with increased morbidity 6, 1.