The effects of opioid-free anesthesia with dexmedetomidine and esketamine on postoperative anesthetic-related complications for hip surgery in the elderly – a randomized controlled trial

Abstract Background: The routine perioperative use of opioids has recently been questioned due to opioid-related side effects, which can be potentially harmful in geriatric patients. This study aimed to evaluate the effects of opioid-free anesthesia in geriatric patients undergoing hip surgery. Methods: A total of 121 patients, aged 60 years or older, undergoing elective hip surgery were randomized to receive either opioid-free anesthesia with dexmedetomidine and esketamine (OFA group) or balanced anesthesia with opioids (CON group). All patients received a preoperative fascia iliaca block and postoperative patient-controlled analgesia using tramadol. The primary outcome was the incidence of a composite of anesthetic-related complications (nausea and vomiting, hypoxemia, ileus, urinary retention and delirium) within 48 hours postoperatively. The hemodynamics, postoperative pain and quality of life were also assessed. Results: The incidence of composite adverse events was significantly reduced in the OFA group compared with the CON group (35.0% vs. 62.3%, estimated difference: 27.3%, 95% confidence interval: 10.2%–44.4%, P = 0.003). Notably, patients in the OFA group experienced less postoperative nausea and vomiting (P = 0.040), and hypoxemia (P = 0.025) compared with those in the CON group. However, the incidences of postoperative ileus, urinary retention and delirium were comparable between the two groups. Also, patients in the OFA group had less pain in motion at 24 h postoperatively, as well as less risks of intraoperative hypotension and bradycardia (P <0.05). No significant differences in the postoperative quality of life were observed between the two groups. Conclusions: Opioid-free anesthesia with dexmedetomidine and esketamine reduced postoperative anesthetic-related complications and provided improved hemodynamic stability in geriatric patients undergoing hip surgery. Trial registration: Chinese Clinical Trial Registry, retrospectively registered on 05/02/2022 (www.chictr.org.cn; ChiCTR2200056421)