Toxicology

Gastric lavage is performed by inserting a larger-bore orogastric or nasogastric catheter tube (36–40

French for adults and 24–28 French for children) with several holes at the distal end into the stomach.

Aliquots of warmed tap water (200–300 mL) are then instilled until there is clearing of aspirated fluid.

minutes of ingestion.

Guidelines emphasize that gastric lavage has not been proven to decrease the severity of illness, improve

recovery times, or improve outcomes (Clin Toxicol 2013;51:140-6).

Should be considered only for life-threatening ingestions when it can be safely performed within 30–60

minutes of ingestion.

Even in life-threatening overdoses, it may not be beneficial. Gastric lavage should not be performed

routinely, if at all, for treating the patient who is poisoned. In the rare situation when it might be

appropriate, clinicians should consider treatment with activated charcoal or observation and supportive

care in place of gastric lavage (Clin Toxicol 2013;51:140-6).

Contraindications for gastric lavage include patients with craniofacial abnormalities, concomitant head

trauma, unprotected airway, increased risk of aspiration, those at risk of GI hemorrhage or perforation

and caustic ingestion such as acids (e.g., boric acid) and alkalis (e.g., dishwasher detergents) because of

the risk of exacerbating any esophageal or gastric injury. Patients with decreased consciousness require

endotracheal or nasal intubation before the procedure.

Complications associated with gastric lavage include aspiration, laryngospasm, perforation of

the esophagus or stomach, arrhythmias, fluid imbalance, hyponatremia, and small conjunctival

hemorrhages.

Used to reduce the transit time of toxins and hence absorption, as well as in combination with activated

charcoal to decrease constipating effects

support improved patient outcomes (J Toxicol Clin Toxicol 2004;42:243-53).

Cathartic use is not recommended; if used, it should be limited to a single dose and not be used as

monotherapy.

Contraindications to cathartic use include absence of bowel sounds, recent GI surgery, intestinal

perforation or obstruction, hypotension, electrolyte disturbances, and renal insufficiency (for

magnesium-based cathartics).

Complications include nausea, dehydration, hypotension, and magnesium imbalances.

Activated charcoal is an adsorbent that works by binding the toxin throughout the GI tract to reduce

systemic absorption. Although activated charcoal binds most substances, Table 3 lists the agents for

which activated charcoal is NOT recommended.

This therapy should be avoided with acids and alkalis because charcoal may cause vomiting, which

can be damaging in these ingestions. The black color and thickness of the activated charcoal may

also cause discoloration of the stomach lining and therefore interfere with endoscopy.

Alcohols bind poorly; therefore, large doses are needed, which are difficult to ingest.

Cyanide will bind, but not with as much activity as other substances. Because the toxic dose of

cyanide is so small, normal doses of activated charcoal may be ineffective.