Evaluation of gastric emptying using radionuclides: gastric lavage versus ipecac-induced emesis

To compare the efficacy of gastric lavage and ipecac-induced emesis by using a radionuclide marker in a simulated overdose and to determine the amount of material recoverable after lavage fluid appears clear.

Case-control, prospective cross-over study.

Nuclear medicine department of Valley Medical Center, Fresno, California.

Fourteen male and five nonpregnant female adult volunteers with no pre-existing gastrointestinal disease and no medication use.

In phase 1, each volunteer ingested 30 capsules labeled with a measured amount of Tc99m with 75 mL H2O followed in five minutes by ipecac-induced emesis. In phase 2, two to four weeks later, each subject was lavaged after ingesting 30 labeled capsules. After lavage appeared clear, a 1,000-mL supplemental lavage was done and analyzed separately. All emesis or gastric lavage fluid was collected and measured for tracer activity.

All subjects in the ipecac group vomited with an average time from ipecac to emesis of 19 minutes. Two subjects withdrew from the study, refusing to complete lavage due to discomfort. Based on retrieved material, ipecac-induced emesis returned significantly more tracer (mean +/- SD, 54.1 +/- 21.3%) than lavage until clear (mean +/- SD, 30.3 +/- 17.4%) (P = .0021). Supplemental lavage returned 12.9% of the total recovered marker (SD, 11.6%). The total of initial and supplemental returns from lavage was 35.5% (SD, 21.0%). This return was significantly less than that returned by ipecac-induced emesis (P = .016).

In this study, ipecac-induced emesis was significantly more effective than gastric lavage in emptying the stomach after simulated overdose. Significant amounts of ingested material are recoverable in gastric lavage return after it appears clear.