Prospective, randomized, double-blind, placebo-controlled comparison of metoclopramide and ondansetron for prevention of posttonsillectomy or adenotonsillectomy emesis

Study Objective: To compare the antiemetic effect of prophylactic ondansetron, metoclopramide, and placebo for prevention of postoperative vomiting in pediatric tonsillectomy or adenotonsillectomy patients. Design: Prospective, randomized, double-blind, placebo controlled study. Setting: Children's hospital. Patients: 132 ASA status I and II children, ages 2 to 12 years, undergoing tonsillectomy or adenotonsillectomy. Interventions: Patients received intravenous (IV) metoclopramide 0.25 mg/kg, IV ondansetron 0.15 mg/kg, or IV saline placebo after induction of standardized halothane, nitrous oxide, and oxygen anesthesia. Muscle relaxants and their antagonists were allowed. Patients received postoperative analgesics as needed. Measurements and Main Results: Incidence of postoperative vomiting, time of vomiting onset, and hospital length of stay (LOS) were measured. Patients who were admitted were excluded from LOS analysis. The postoperative incidence of vomiting was 54% for patients receiving metoclopramide, 26% for patients receiving ondansetron versus metoclopramide (p = 0.008) and placebo (p = 0.001). The mean (SD) LOS was significantly shorter for patients not vomiting: 488 (88) minutes for vomiters versus 435 (65) minutes for nonvomiters. Conclusions: Prophylactic ondansetron is more effective than metoclopramide or placebo for the prevention of vomiting after tonsillectomy or adenotonsillectomy. Patients who do not vomit postoperatively have shorter LOS. (C) 1996 Elsevier Science Inc.