Removal of ingested poisons by induced emesis or gastric lavage was a routine part of emergency treatment for decades. However, prospective randomized studies have failed to demonstrate improved clinical outcome after gastric emptying. For small or moderate ingestions of most substances, toxicologists often recommend oral activated charcoal alone without prior gastric emptying; in some cases, when the interval after ingestion has been more than 1–2 hours and the ingestant is non–life-threatening, even charcoal is withheld (eg, if the estimated benefit is outweighed by the potential risk of pulmonary aspiration of charcoal). Exceptions are large ingestions of anticholinergic compounds and salicylates, which often delay gastric emptying, and ingestion of sustained-release or enteric-coated tablets, which may remain intact for several hours. In these cases, delayed gut decontamination may be indicated.
Gastric emptying is not generally used for ingestion of corrosive agents or petroleum distillates, because further esophageal injury or pulmonary aspiration may result. However, in certain cases, removal of the toxin may be more important than concern over possible complications. Consult a medical toxicologist or regional poison control center (1-800-222-1222) for advice.
Emesis using syrup of ipecac can partially evacuate gastric contents if given very soon after ingestion. However, it is no longer used in the routine management of ingestions because it increases the risk of pulmonary aspiration and may delay or prevent the use of oral activated charcoal.
Gastric lavage is more effective for liquid poisons or small pill fragments than for intact tablets or pieces of mushroom. It is most useful when started within 60 minutes after ingestion. However, the lavage procedure may delay administration of activated charcoal and may stimulate vomiting and pulmonary aspiration in an obtunded patient.
1. Indications—Gastric lavage is sometimes used after very large ingestions (eg, massive aspirin overdose), for collection and examination of gastric contents for identification of the poison, and its use makes it easier to administer charcoal and oral antidotes.
2. Contraindications—Do not use lavage for stuporous or comatose patients with depressed airway protective reflexes unless they are endotracheally intubated beforehand. Some authorities advise against lavage when caustic material has been ingested; others regard it as essential to remove liquid corrosives from the stomach.
3. Technique—In obtunded or comatose patients, the danger of aspiration pneumonia is reduced by performing endotracheal intubation with a cuffed tube before the procedure. Gently insert a lubricated, soft but noncollapsible stomach tube (at least 37–40 F) through the mouth or nose into the stomach. Aspirate and save the contents, and then lavage repeatedly with 50- to 100-mL aliquots of fluid until the return fluid is clear. Use lukewarm tap water or saline.
Activated charcoal effectively adsorbs almost all drugs and poisons. Poorly adsorbed substances include iron, lithium, potassium, sodium, mineral ...