Benefits of dexmedetomidine on postoperative analgesia after bariatric surgery: a systematic review and meta-analysis

INTRODUCTION: Anesthetic management of morbidly obese patients is challenging, particularly in those undergoing bariatric surgery. Dexmedetomidine is a α2-adrenergic receptor agonist that is increasingly used in the perioperative setting for its beneficial properties including sedation, anxiolysis, analgesia with opioid-sparing effects, and minimal impact on respiration. The objective of this study was to evaluate the effect of dexmedetomidine on postoperative analgesia and recovery-related outcomes among patients undergoing bariatric surgery. EVIDENCE ACQUISITION: We conducted a systematic review and meta-analysis of MEDLINE, EMBASE, and CENTRAL databases from conception to September 2021 for randomized controlled trials (RCTs) using dexmedetomidine in bariatric patients on postoperative outcomes. Outcomes were pooled using random effects model and presented as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI). EVIDENCE SYNTHESIS: In total, 20 RCTs with 665 patients in the dexmedetomidine group and 671 patients in the control groups were included. Among RCTs, the dexmedetomidine group had significantly lower opioid usage at 24-hours postoperatively (MD: -5.14, 95% CI: -10.18 to -0.10; moderate certainty), reduced pain scores on a 10-point scale at PACU arrival (MD: -1.69, 95% CI: -2.79 to -0.59; moderate certainty) and six hours postoperatively (MD: -1.82, 95% CI: -3.00 to -0.64; low certainty), and fewer instances of nausea (RR: 0.59, 95% CI: 0.45 to 0.75; moderate certainty) and vomiting (RR: 0.25, 95% CI: 0.15 to 0.43; moderate certainty), compared to control groups. CONCLUSIONS: Dexmedetomidine is an efficacious anesthesia adjunct in patients undergoing bariatric surgery. These benefits of dexmedetomidine may be considered in the multi-modal analgesic management and enhanced recovery pathways in this high-risk population.