Droperidol versus haloperidol on postoperative nausea and vomiting: a retrospective analysis

Introduction: Butyrophenones are effective prophylactic drugs against postoperative nausea and vomiting (PONV). Our practice used droperidol for PONV prophylaxis until supply chain issues in 2020 required a substitution to haloperidol. Objective: To compare the use of these two butyrophenones and their association with the magnitude of reduction PONV and sedation during admission to postanesthesia care unit (PACU). Methods: Retrospective review of the records of adult surgical patients administered a butyrophenone and admitted to the PACU, from May 2018 through December 2022. PONV was defined as administration of rescue antiemetics during PACU admission. Inverse probability of treatment weighing (IPTW) analysis was performed using generalized estimating equations with robust variance estimates to assess the effects of droperidol and haloperidol on PONV rate. Results: We identified 905 (2018 – 2020) and 651 patients (2020 – 2022) receiving droperidol or haloperidol, respectively. The IPTW PONV rate was 75 (8.3%) for droperidol and 84 (12.9%) haloperidol (odds ratio 0.60; 95% confidence interval 0.41 to 0.87, for the use of droperidol vs haloperidol). Moderate or higher levels of sedation (Richmond Agitation Sedation Scale score ≤ -3) was noted in 163 (18.0) of droperidol and 102 (15.7%) of haloperidol patients, which was nonsignificant, P=0.222, following IPTW adjustment, P=0.269. Median [interquartile range] PACU length of stay was comparable for two butyrophenones, 70 [51, 99] vs. 68 [48, 105] minutes for droperidol vs haloperidol, respectively, P=0.647. Conclusion: Droperidol was associated with lower rates of PONV during PACU admission than haloperidol, but the rate of sedation was higher.