Gut decontamination in the poisoned patient

Abstract

Poisoning management includes gastrointestinal decontamination strategies to decrease the burden of poison entering the body and change the expected severe toxicity expected to a less toxic, more favourable outcome. Common modalities are orogastric lavage, oral-activated charcoal and whole-bowel irrigation. Endoscopic retrieval and laparotomy are rare options reserved for severe ingestions and body packers. Although supporting data are generally of low quality, gastrointestinal decontamination is likely to improve patient outcome in many situations. Unfortunately, technical limitations and contraindications can explain their infrequent use. Orogastric lavage can be useful for early lethal ingestions, albeit with significant complications such as aspiration and perforation. Activated charcoal cannot adsorb every substance. Usual dosing is 1 g/kg per dose. Whole-bowel irrigation is reserved for charged molecules or substances not adsorbed to activated charcoal but requires intact gut motility. Indications depend on several factors inherent to the ingestion (dose, time, poison) and patient's characteristics. During recent decades, studies of newer pharmaceuticals or modified-release formulations showed that significant amounts of poison, especially pharmacobezoars, persist in the gut hours postingestion, thus are amenable to gastrointestinal decontamination. Improved understanding of gut motility in volunteer studies and overdose showed clinically significant reduction in drug exposure with activated charcoal. The 1-h dogma for gastrointestinal decontamination, especially activated charcoal, is now obsolete. Clinicians must perform a risk assessment for each ingestion to determine the expected benefit at the time of decision-making, choosing the modality to achieve reduction in the toxicity burden while planning for complications or contraindications.

Keywords: clinical toxicology; critical care; emergency medicine; overdose; poisoning.