Effect of opioid-free anesthesia on postoperative sleep disturbance after thyroidectomy: a randomized clinical trial

Background: Postoperative sleep disturbance (PSD) is common after thyroid surgery, and perioperative opioid use is a major contributing factor. We hypothesized that opioid-free anesthesia (OFA) would reduce PSD among patients undergoing thyroidectomy. Methods: A total of 160 adults were randomly assigned to receive either OFA or opioid-based anesthesia (OBA). All participants received a preoperative bilateral superficial cervical plexus block, intravenous propofol and lidocaine infusion, and desflurane inhalation. The OFA group received intraoperative esketamine and dexmedetomidine, while the OBA group received alfentanil followed by a remifentanil infusion. Sleep architecture on postoperative day (POD) 1 was measured with the Fitbit Charge 2 ® smart wristband. The primary outcome was the incidence of PSD on POD 1. Results: The median age was 46 years, and 81.3% of participants were female. Compared with OBA, OFA significantly reduced the incidence of PSD on POD 1 [38.8% vs. 63.8%; odds ratio (OR) = 0.36, 95% confidence interval (CI), 0.19–0.68; P = 0.002] and POD 3 (3.8% vs. 15%; OR = 0.22, 95% CI, 0.06–0.82; P = 0.01). OFA increased the proportion of deep sleep time by 39.7% and shortened light sleep time by 6.2% on POD 1. Additionally, OFA enhanced the early quality of recovery and reduced the incidence of hypotension, postoperative nausea and vomiting, and hypoxemia. However, a prolonged length of post-anesthesia care unit stay and tracheal extubation time were observed in the OFA group. Conclusion: The OFA group reduced the incidence of PSD after thyroidectomy, possibly by prolonging deep sleep, shortening light sleep, and modulating the sleep architecture.