Aprepitant versus ondansetron in preoperative triple-therapy treatment of nausea and vomiting in neurosurgery patients: study protocol for a randomized controlled trial

BACKGROUND: The incidence of postoperative nausea and vomiting (PONV) is 50% to 80% after neurosurgery. The common prophylactic treatment for postoperative nausea and vomiting is a triple therapy of droperidol, promethazine and dexamethasone. Newer, more effectives methods of prophylaxis are being investigated. We designed this prospective, double-blind, single-center study to compare the efficacy of ondansetron, a neurokinin-1 antagonist, and aprepitant, as a substitute for droperidol, in the prophylactic treatment of postoperative nausea and vomiting after neurosurgery. METHODS: After obtaining institutional review board approval; 176 patients, 18 to 85 years of age with American Society of Anesthesiologists (ASA) classifications I to III, who did not receive antiemetics 24 h before surgery and were expected to undergo general anesthesia for neurosurgery lasting longer than 2 h were included in this study. After meeting the inclusion and exclusion criteria and providing written informed consent, patients were randomly assigned in a 1:1 ratio to one of two treatment groups: aprepitant or ondansetron. The objective of this study was to conduct a randomized, double-blind, double-dummy, parallel-group and single-center trial to compare and evaluate the efficacies of aprepitant versus ondansetron. Patients received oral aprepitant 40 mg OR oral dummy pill within 2 h prior to induction. At induction, a combination of intravenous dexamethasone 10 mg, promethazine 25 mg, and ondansetron 4 mg OR dummy injection was administered. Therefore, all patients received one dummy treatment and three active PONV prophylactic medications: dexamethasone 10 mg, promethazine 25 mg, and either aprepitant 40 mg OR ondansetron 4 mg infusion. The primary outcome measures were the episodes and severity of nausea and vomiting; administration of rescue antiemetic; and opioid consumption for 120 h postoperatively. Standard safety assessments included adverse event reports, physical and laboratory data, awakening time and duration of recovery from anesthesia. DISCUSSION: The results of this comparative study could potentially identify an improved treatment regimen that may decrease the incidence and severity of postoperative nausea and vomiting in patients undergoing neurosurgery. Also, this will serve to enhance patient recovery and overall satisfaction of neurosurgical patients in the immediate postoperative period. TRIAL REGISTRATION: Registered at The Ohio State University Biomedical Sciences Institutional Review Board: Protocol Number: 2007 H0053