Low-dose Ondansetron with Dexamethasone More Effectively Decreases Vomiting after Strabismus Surgery in Children than Does High-dose Ondansetron

Abstract

Background Ondansetron and dexamethasone have been observed to decrease the incidence of vomiting by children after general anesthesia. This study compared the effect of high-dose (150 microg/kg) ondansetron with low-dose (50 microg/kg) ondansetron plus 150 microg/kg dexamethasone on the incidence of vomiting after strabismus in children. Methods This study had a double-blind, blocked, stratified, randomized design. With parental consent and Hospital Ethics Committee approval, healthy children aged 2-14 yr who were undergoing elective strabismus surgery were studied. Anesthesia was induced intravenously with propofol or by inhalation with halothane and nitrous oxide. Patients in the high-dose group were given placebo plus 150 microg/kg (maximum dose, 8 mg) of ondansetron intravenously, whereas patients in the low-dose group were given 150 microg/kg dexamethasone (maximum dose, 8 mg) and 50 microg/kg ondansetron intravenously in a double-blind manner. Anesthesia was maintained with halothane and nitrous oxide. All incidences of vomiting occurring as long as 24 h after anesthesia were recorded. Results Three of the 200 patients enrolled in the study were excluded from data analysis. The groups were similar with respect to demographic data and potential confounding variables. Patients vomited from 0-12 times. The low-dose ondansetron plus dexamethasone group had a lower incidence of vomiting, 9% (95% CI = 4-17%) versus 28% (95% CI = 20-38%; P < 0.001). Only 1% of the patients in the low-dose ondansetron plus dexamethasone group vomited while in the hospital. Conclusions Low-dose ondansetron plus dexamethasone is an effective prophylactic antiemetic combination for children undergoing strabismus surgery.