Does gastric lavage really push poisons beyond the pylorus? A systematic review of the evidence

Abstract

Classically, treatment of acute self-poisoning involves resuscitation and supportive care, followed by gastric emptying, administration of activated charcoal, and use of specific antidotes. Recently, however, the practice of gastric emptying has fallen out of favor in the West because physicians have recognized its complications and the lack of evidence for clinical benefit from its practice. Authoritative position statements have stated that forced emesis should not be used and that gastric lavage should be used in restricted settings. One commonly cited complication of gastric lavage is propulsion of poison beyond the pyloric sphincter into the small bowel. We have carried out a systematic search for studies addressing this issue and found only 2. The first, a randomized controlled trial of patients presenting to an emergency department, reported propulsion of poison into the small bowel and has been widely cited as showing evidence for such a complication. However, analysis of the data presented in this article shows no significant difference in the number of radio-opaque marker pellets present in the small bowel after gastric lavage, ipecac-induced forced emesis, or no intervention. The second, an observational study using human volunteers, showed significantly less poison in the small bowel after gastric lavage than after no intervention. In conclusion, it seems that no published data support the statement that gastric lavage forces poison into the small bowel.

Introduction

Classic teaching on the treatment of self-poisoning recommends resuscitation and supportive care, followed by gastric emptying, administration of activated charcoal, and use of specific antidotes. However, gastric emptying has fallen out of favor with clinical toxicologists throughout the past decade because of its poor efficacy and obvious complications. Indeed, the American and European clinical toxicology societies published joint position statements in 19971, 2 that recommended restricted use of gastric lavage and forced emesis. Physicians have taken their lead from these guidelines, and these procedures are now much less often practiced in the West.3, 4, 5, 6, 7, 8

A physician's decision to use gastric lavage for any particular patient must depend on an assessment of the procedure's relative risks and benefits. No clinical trials have yet compared gastric lavage alone with no gastric emptying; however, gastric lavage and activated charcoal have been compared with activated charcoal alone in 3 large trials.9, 10, 11 Although the trials have methodologic faults,1, 12 they gave consistent results, and none showed a benefit of adding lavage to routine activated charcoal therapy. Current guidelines, therefore, indicate that only activated charcoal need be considered for most patients.1, 13, 14

If the risks of giving lavage are low, then perhaps it is reasonable to carry out lavage without any evidence of benefit. Complications of lavage include laryngospasm; hypoxia; hypercapnia; aspiration pneumonia; fluid and electrolyte imbalance; and mechanical injury to, or perforation of, throat, esophagus, and stomach.¹ Such adverse events are said to be rare, although no studies have been performed to accurately determine their incidence. Clearly, the risk of adverse events can be minimized by careful selection and preparation of patients. In particular, lavage should be performed only in alert patients who are fully cooperative or in patients who have reduced consciousness and protected airways.1, 15, 16

A further, often cited,1, 6, 8, 11, 17, 18, 19 complication of gastric lavage is propulsion of gastric contents, including the poison, through the pylorus into the small bowel. Because the surface area of the small bowel is far greater than that of the stomach and the majority of poisons are absorbed from the small bowel, lavage-induced propulsion of poison risks increasing the severity of acute poisoning or speeding its onset, with detrimental consequences.

As part of a general evaluation of gastric lavage, we systematically searched for studies that addressed gastric lavage–induced propulsion of poison into the small bowel. We aimed to critically assess the quality of the evidence for this complication.