A small dose of droperidol decreases postoperative nausea and vomiting in adults but cannot improve an already excellent patient satisfaction

Background: We evaluated whether or not 1) a routine prophylaxis with 20 μg  ·  kg−1 body weight of droperidol would efficiently prevent postoperative nausea and vomiting (PONV) after elective surgery in adults and 2) an efficient prophylaxis would improve patient satisfaction. Methods: With approval of the local ethics committe and after having obtained informed written consent, 1334 patients in a randomised, single-blinded fashion either received droperidol (group 1, n=665) or saline intravenously (group 2, n=669) 20 min before the end of a standard O2/N2O/fentanyl/isoflurane anaesthesia of at least 30 min duration. End points: incidence of PONV during the first 24 h; individual episodes of nausea or vomiting, overall patient satisfaction with the procedure. Results: Compared to saline, intravenous injection of droperidol substantially and significantly reduced the incidence of PONV from 30% to 20% (P<0.0001). Women suffered three times more frequently from PONV (10.5% vs. 30%, P<0.0001). Droperidol significantly reduced the incidence of PONV from 35.4% to 24.4% in women (relative risk reduction: 31%, P=0.0002), but not in men (13.1% vs. 8.2%, relative risk reduction: 37%, P=0.159) – without impact on overall patient satisfaction (98.8% vs. 97.1%, P=0.439). Distribution of surgical procedures, sex, age, height, weight and anaesthetic duration were not different between groups. To prevent one woman from suffering PONV, nine had to be treated prophylactically at an individual drug cost (German prices) of about  0.80 per woman. Conclusion: Routine PONV prophylaxis with 20 μg  ·  kg−1 body weight of droperidol is cost-efficient and appropriate in women but not in men.