Effects of opioid-free total intravenous anesthesia on postoperative nausea and vomiting after treatments of lower extremity wounds: protocol for a randomized double-blind crossover trial

Abstract

Abstract Background Postoperative nausea and vomiting (PONV) are common after general anesthesia and surgery. This study aims to compare the effects of total intravenous opioid-free anesthesia (OFA) with conventional opioid-based anesthesia (OBA) on PONV in patients following treatments for wounds of lower extremities. Methods This randomized, double-blind, crossover trial will include a total of 72 adult patients scheduled for at least two separate surgical treatments of lower extremity wounds under general anesthesia. Patients will be randomized to 1 of 2 anesthesia sequences of OFA and OBA. Patients in sequence 1 will receive OFA in the first treatment procedure and OBA in the second procedure, while patients in sequence 2 will receive the two anesthesia regimens in the reverse order. The washout period is at least 5 days. OFA will be delivered with intravenous esketamine, lidocaine, dexmedetomidine, and propofol. OBA will be delivered with intravenous sufentanil and propofol. The primary endpoint is the incidence of PONV within the first 48 h postoperatively. The secondary endpoints are the severity of PONV, antiemetic rescue therapy, postoperative pain scores, the worst pain, need for rescue analgesia, postoperative sedation, hypotension, bradycardia, hypertension, tachycardia, hypoxemia, psychotomimetic or dissociative effects, time to extubation, and length of postanesthesia care unit stay. Patients who complete two surgical procedures with designated anesthesia regimens will be included in the final analyses. Discussion This crossover trial will determine whether total intravenous OFA reduces PONV in patients following treatments for lower extremity wounds. The results of this trial will also represent an important step to understand the benefits and possible risks of OFA in surgical patients. Trial registration Chinese Clinical Trial Registry (ChiCTR2200061511).