Antiemetic prophylaxis with droperidol in morphine-based intravenous patient-controlled analgesia: a propensity score matched cohort study

Background: There are limited real-world data regarding the use of droperidol for antiemetic prophylaxis in intravenous patient-controlled analgesia (IV-PCA). This study aimed to evaluate the antiemetic benefits and sedation effects of droperidol in morphine-based IV-PCA. Methods: Patients who underwent major surgery and used morphine-based IV-PCA at a medical center from January 2020 to November 2022 were retrospectively analyzed. The primary outcome was the rate of any postoperative nausea and/or vomiting (PONV) within 72 h after surgery. Propensity score matching was used to match patients with and without the addition of droperidol to IV-PCA infusate in a 1:1 ratio. Multivariable conditional logistic regression models were used to calculate adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results: After matching, 1,104 subjects were included for analysis. The addition of droperidol to IV-PCA reduced the risk of PONV (aOR: 0.49, 95% CI: 0.35–0.67, p < 0.0001). The antiemetic effect of droperidol was significant within 36 h after surgery and attenuated thereafter. Droperidol was significantly associated with a lower risk of antiemetic uses (aOR: 0.58, 95% CI: 0.41–0.80, p = 0.0011). The rate of unintentional sedation was comparable between the patients with (9.1%) and without (7.8%; p = 0.4481) the addition of droperidol. Postoperative opioid consumption and numeric rating scale acute pain scores were similar between groups. Conclusions: The addition of droperidol to IV-PCA reduced the risk of PONV without increasing opiate consumption or influencing the level of sedation. However, additional prophylactic therapies are needed to prevent late-onset PONV.