[Meta-analysis of controlled randomized studies on droperidol for prevention of postoperative phase vomiting and nausea].

OBJECTIVE

Randomised, controlled trials using prophylactic droperidol to prevent postoperative nausea and vomiting (PONV) were included in a meta-analysis to estimate efficiency and dose-response of treatment.

MATERIALS AND METHODS

Studies were systematically extracted from Medline, the manufacturer's database, and a supplemental search of references lists and current issues of locally available anaesthesia journals. Complete prevention of PONV defined as absence of nausea, retching, and vomiting within 6 hours (early PONV) and within 48 hours (late PONV) was chosen as the main end point. Additional information such as dose of droperidol, time and way of administration, and biometric data of the patients were extracted from each study. The pooled relative risk and the number-needed-to treat (NNT) were calculated.

RESULTS

A total of 72 studies with 107 comparative subgroups were accepted for analysis according to the prospectively defined criteria. Of these sixty-nine trials reported a lower incidence of PONV with droperidol. The incidence of early and late PONV among the 5370 patients receiving droperidol was 23.4% and 38.2%, respectively. The corresponding incidence among the 3954 control patients was 40.7% and 53.9%. The relative risk for patients receiving prophylactic droperidol of suffering from early PONV was 0.58 and 0.71 for late PONV. The NNT for preventing one patient from PONV was 5.8 and 6.4 for early and late PONV, respectively. Treatment with droperidol was more effective when the baseline risk for PONV was higher than 25% for early PONV and 35% for late PONV. Under these circumstances the NNT was between 2.6 and 5.6. There was no dose response relationship for droperidol when the drug was applied in doses ranging from 0.5 to 300 micrograms.kg-1 body weight. It was not possible to derive reliable information about the incidence of side-effects of the droperidol administration.

CONCLUSION

Droperidol is an effective antiemetic drug. The drug can be administered to patients with an increased risk of suffering from PONV without antiemetic prophylaxis. Since a positive dose response is lacking, droperidol should only be administered in doses of 1 mg or less.