Prophylactic ondansetron for postoperative emesis. Meta-analysis of its effectiveness in patients with previous history of postoperative nausea and vomiting.
BACKGROUND
The objective of this study was to compare, by means of meta-analysis, the postoperative antiemetic efficacy of ondansetron in patients with and without antecedents of postoperative nausea and vomiting.


METHODS
MEDLINE and EMBASE databases were searched for randomised placebo-controlled trials which evaluated the antiemetic effectiveness of 4 mg and 8 mg intravenous doses of prophylactic ondansetron in adult patients. A further selection was with respect to those studies which noted the patient's previous history of postoperative nausea and vomiting (PH-PONV) and, for the meta-analysis, the patients were divided into two sub-groups: those with (PH-PONV +) and those without a previous history of postoperative nausea and vomiting (PH-PONV -). Absence of vomiting was used as the index of effectiveness.


RESULTS
Twenty-one trials involving 3984 patients (2446 in ondansetron groups and 1538 in placebo groups; 1163 PH-PONV(+) patients and 2821 PH-PONV(-) patients) met the selection criteria. The effectiveness of the 4 mg dose of ondansetron was: OR (95% CI)=2.40 (1.77-3.26) vs. 2.71 (2.23-3.30) for the patients of PH-PONV(+) and PH-PONV(-) sub-groups, respectively. For the 8 mg dose, the effectiveness of ondansetron was: PH-PONV(+)=4.21 (2.66-6.66) and PH-PONV(-)=2.61 (1.81-3.59). For neither of the doses evaluated was there any significant statistical difference between the sub-groups.


CONCLUSIONS
The effectiveness of ondansetron in the prevention of postoperative vomiting is not affected by the patients' PH-PONV.
Figueredo
E
E
Department of Anaesthesiology, Torrecardenas Hospital, Almería, Spain.
Canosa
L
L
D000328:Adult; D000932:Antiemetics / Q000627:therapeutic use*; D006801:Humans; D017294:Ondansetron / Q000627:therapeutic use*; D020250:Postoperative Nausea and Vomiting / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
D000932:Antiemetics; D017294:Ondansetron