Postoperative nausea and vomiting after bariatric surgery and dexmedetomidine anesthetic: a propensity-weighted analysis

Background: Patients undergoing laparoscopic bariatric surgery have high rates of postoperative nausea and vomiting (PONY). Dexmedetomidine based anesthetic could reduce PONY rates. Objectives: To determine if PONY rates differ in patients undergoing laparoscopic bariatric surgery with anesthesia primarily based on dexmedetomidine or standard anesthetic management with inhalational agents and opioids. Setting: University hospital. Methods: From January 2014 to April 2018, 487 patients underwent laparoscopic bariatric surgery and met inclusion criteria (dexmedetomidine, n = 174 and standard anesthetic, n = 313 patients). In both groups, patients received preoperative PONY prophylaxis. We analyzed rates of PONY and moderate-to-deep sedation. A propensity score was calculated and outcomes were assessed using generalized estimating equations with inverse probability of treatment weighting. Results: Perioperative opioids and volatile anesthetics were reduced in dexmedetomidine patients. During anesthesia recovery the incidence of PONY was similar between dexmedetomidine and standard anesthetic patients (n = 37 [21.3%] versus n = 61 [19.5%], respectively; inverse probability of treatment weighting odds ratio = 1.35; 95% confidence interval .78-2.32, P = .281), and the incidence of sedation higher in dexmedetomidine patients (n = 86 [49.4%] versus n = 75 [24.0%]; inverse probability of treatment weighting odds ratio = 2.43; 95% confidence interval 1.47-4.03, P < 0.001). Rates of PONY and sedation were similar during the remainder of the hospital stay. A secondary sensitivity analysis was performed limited to dexmedetomidine patients who did not receive volatile and results were similar. Conclusions: While dexmedetomidine-based anesthesia was associated with reduced opioid and volatile agents use, it was not associated with a reduction of PONY. The higher rates of moderateto-deep sedation during anesthesia recovery observed with dexmedetomidine may be undesirable in morbidly obese patients. (C) 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.