Contribution of pharmacist intervention to postoperative nausea and vomiting prophylaxis in routine multidisciplinary practice: a retrospective observational study.

Abstract

Background: Postoperative nausea and vomiting (PONV) is a common surgical complication that delays recovery and increases healthcare costs. Although U.S. guidelines recommend multimodal, risk-stratified prophylaxis, Japan lacks unified national guidelines, resulting in practice variation. Despite expanded insurance coverage for 5-HT₃ receptor antagonists, sustained adherence to best practices requires a multidisciplinary framework. We implemented a pharmacist-led, multidisciplinary PONV prevention protocol and evaluated its impact on PONV incidence among adults undergoing elective surgery across multiple specialties.

Methods: We developed a pharmacist-led multidisciplinary PONV prevention protocol based on U.S. guideline algorithms, recommending ≥ 2 and ≥3 prophylactic agents for medium- and high-risk patients, respectively. Pharmacists in the admission support center collected preoperative risk factors, while operating room pharmacists relayed assessments to anesthesiologists and nurses. We conducted a retrospective observational study of patients aged ≥ 18 years undergoing elective gastrointestinal or gynecological surgery under general anesthesia. We compared 110 and 255 patients in the pre- and post-intervention groups, respectively, focusing on patients at medium to high risk. For primary analysis, we performed 1:1 propensity score matching (PSM) using five covariates to control for confounding. Conditional logistic regression evaluated intervention effects while accounting for the matched design.

Results: The final analysis included 106 controls and 243 intervention patients. PSM produced 103 well-balanced matched pairs (standardized differences < 0.1). Conditional logistic regression showed that the pharmacist-led intervention significantly reduced PONV occurrence (odds ratio [OR] 0.308, 95% confidence interval [CI], 0.139-0.680). Prophylactic agent use increased significantly after the intervention (OR 3.95, 95% CI 2.43-6.54), with dexamethasone (OR 5.92, 95% CI 3.03-11.60) and 5-HT₃ receptor antagonists (OR 4.98, 95% CI 2.69-9.22) showing the largest increases. Dopamine antagonists and total intravenous anesthesia administration also showed upward trends, though without statistical significance.

Conclusions: The implementation of a pharmacist-led multidisciplinary PONV prevention protocol was associated with a lower incidence of PONV in medium- to high-risk patients. Pharmacist-conducted preoperative risk assessment improved the implementation of risk-based prophylaxis within a multidisciplinary framework. These findings suggest that pharmacist-driven collaborative approaches may facilitate more consistent PONV prophylaxis in clinical settings lacking unified guidelines.