Background and Goal of Study: Very low doses of droperidol may prevent postoperative nausea and vomiting (PONV). Dose-responsiveness remains unclear.
Materials and Methods: We performed a systematic search (databases, bibliographies, to 10.2010) for full reports of randomised comparisons of single shot, IV, low-dose droperidol (≤1 mg or ≤15 μg/kg) with placebo, for the prevention of PONV in adults undergoing general anaesthesia. We estimated risk ratios (RR) with 95% confidence intervals (CI) of early (to 6 hours) and late (to 48 hours) PONV symptoms, and adverse effects. We compared aggregated data of predefined dose-ranges using Cochrane statistics to search for doseresponsiveness.
Results and Discussion: We included 24 studies (2917 patients, 1505 received droperidol), published between 1984 and 2008. Droperidol regimens varied between 0.25 and 1 mg. Compared with placebo, droperidol prevented early nausea (RR 0.45 [95% CI 0.35-0.58]), late nausea (RR 0.81 [0.75-0.87]), early vomiting (RR 0.65 [0.57 to 0.74]) and late vomiting (RR 0.73 [0.66 to 0.81]). For none of these endpoints, there was any evidence of dose responsiveness. With droperidol, the risk of restlessness was significantly increased, independent of the dose (RR 3.61 [1.90 to 6.87]). The risk of headache was decreased with doses ≥0.7 mg (RR 0.35 [0.18 to 0.69]). Two episodes of extrapyramidal symptoms were reported, both with droperidol. The risk of sedation, and the times to awakening, orientation or home readiness were not increased.
Conclusion(s): Prophylactic IV single-dose droperidol, 0.25 to 1 mg, prevents PONV symptoms independent of the dose but increases the risk of postoperative restlessness. The risk of headache is decreased with doses ≥0.7 mg.