Management issues in toxicology.
The lack of evidence-based information in toxicology results in debate and differing recommendations on management issues. Gastric lavage is often utilized to remove toxins from the stomach but a clinical benefit of the procedure has not been definitively demonstrated. A selective approach is warranted in each patient, and gastric lavage can be considered in patients with life-threatening ingestions if it can be performed within 60 minutes of ingestion. Whole bowel irrigation is a method of GI decontamination utilizing isotonic electrolyte solution. Although safe, there is currently insufficient data to establish definite indications for use. This technique can be considered for potentially toxic ingestions of lithium, iron, and sustained-release or enteric-coated drugs. Multiple-dose activated charcoal has been used to enhance elimination of drugs already absorbed into the body but the optimum dose and frequency of administration is not established. Based on volunteer studies and limited clinical reports, multiple-dose activated charcoal may be considered in patients with life-threatening ingestions of carbamazepine, dapsone, phenobarbital, quinine, or theophylline. A variety of interventions in addition to hemodialysis have been proposed to enhance lithium elimination. Forced saline diuresis and diuretics are not indicated. Although studies suggest that sodium polystyrene sulfonate may enhance elimination of lithium, no beneficial effects on clinical outcomes have been demonstrated and potential complications include hypokalemia and hypernatremia. Blood alkalinization for cyclic antidepressant toxicity has become standard therapy. Alkalinization is most effective in treating significant cardiac toxicity. Sodium bicarbonate, rather than hyperventilation, should be used initially to alkalinize blood. The benefit of blood alkalinization in the treatment of hypotension and seizures is not established.
Zimmerman
J L
JL
Baylor College of Medicine, Houston, Texas 77030, USA. janicez@bcm.tmc.edu