Studies on the efficacy of gastric lavage as practiced in a large metropolitan hospital.

The efficacy of gastric lavage as it is practiced in a major metropolitan hospital was evaluated. From a population of 76 patients with chemical evidence of sedative-hypnotic drugs in the blood, two or more therapeutic doses were recovered from 15.8% of the lavage samples, and 10 or more therapeutic doses were recovered from 6.6%. In a population consisting of patients with detectable quantities of drugs in the lavage sample, diazepam and amitriptyline are more adequately recovered than the sedative-hypnotic drugs. Very poor recoveries were obtained in patients lavaged more than 2 h after ingestion except in cases of amitriptyline overdose or massive sedative-hypnotic ingestion. The study indicates that inadequate criteria are employed in selecting patients most likely to benefit from lavage. Dose, time since ingestion, and symptomatology are discussed as criteria for selection of patients for lavage.