title: Vomiting after adenotonsillectomy in children: a comparison of ondansetron, dimenhydrinate, and placebo.
abstract: We compared the effectiveness of ondansetron, dimenhydrinate, and placebo for the prevention of postoperative vomiting in children after adenotonsillectomy. In a randomized, placebo-controlled, double-blind study, 74 children, 2-10 yr of age scheduled for adenotonsillectomy as outpatients were given a single i.v. dose of ondansetron (0.1 mg/kg, n = 26), dimenhydrinate (0.5 mg/kg, n = 25), or placebo (saline, n = 23) at induction of anesthesia. The incidence of retching and vomiting (POV) and side effects observed 24 h after surgery were recorded. Demographic data were similar among the three groups. The 24-h incidence of POV was 42%, 79%, and 82% in the ondansetron, dimenhydrinate, and placebo groups, respectively (ondansetron compared with dimenhydrinate [P < 0.02] or placebo [P < 0.01]). The study was stopped after two children vomited large volumes of bloody fluid 9 and 22 h after surgery without previous signs of occult bleeding. Both children had received ondansetron. We conclude that ondansetron is superior to dimenhydrinate or placebo for the prevention of POV after adenotonsillectomy in children. Antiemetics may mask the signs of bleeding after adenotonsillectomy.
  
  
  CONCLUSIONS
  I.v. ondansetron (0.1 mg/kg) is more effective than both dimenhydrinate and placebo in preventing vomiting after adenotonsillectomy in healthy children. However, antiemetics may also mask the presence of blood in the stomach by preventing vomiting, and this should be appreciated when adenotonsillectomy is performed on an outpatient basis.
authors.affiliation: Department of Anaesthesia and the Research Institute, The Hospital for Sick Children and University of Toronto, Ontario, Canada.
authors.forename: S K
authors.initials: SK
authors.lastname: Hamid
authors.forename: I R
authors.initials: IR
authors.lastname: Selby
authors.forename: N
authors.initials: N
authors.lastname: Sikich
authors.forename: J
authors.initials: J
authors.lastname: Lerman
mesh_terms: D000932:Antiemetics / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004111:Dimenhydrinate / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D017294:Ondansetron / Q000627:therapeutic use*; D014068:Tonsillectomy / Q000379:methods*
chemical_list: D000932:Antiemetics; D017294:Ondansetron; D004111:Dimenhydrinate