Effects of opioid-free anesthesia combined with iliofascial nerve block on perioperative neurocognitive deficits in elderly patients undergoing hip fracture surgery: study protocol for a prospective, multicenter, parallel-group, randomized controlled trial.

Background: Perioperative neurocognitive dysfunction (PND), a prevalent complication affecting elderly surgical patients, poses substantial challenges to postoperative rehabilitation and long-term functional independence. Despite growing awareness of its clinical significance, current evidence regarding effective neuroprotective anesthetic strategies remains inconclusive. Where emerging evidence suggests opioid-free anesthesia (OFA) strategies could maintain analgesic efficacy while potentially attenuating opioid-associated neuroinflammatory mechanisms implicated in PND pathogenesis. This multicenter trial investigates the efficacy of OFA combined with ultrasound-guided iliofascial nerve block in mitigating PND among geriatric patients undergoing hip fracture surgery.

Methods: This multicenter, randomized controlled trial will enroll 348 patients, who will be randomly assigned to receive either OFA combined with iliofascial nerve block or opioid-based anesthesia (OBA) combined with iliofascial nerve block. All patients will undergo hip fracture surgery under general anesthesia with tracheal intubation. The primary outcome will be the change in composite neurocognitive scores, assessed through a battery of neuropsychological tests from baseline to 3 months postoperatively. Secondary outcomes include alterations in serum protein and inflammatory markers, extubation time, postoperative pain incidence, intraoperative hemodynamic stability, and postoperative recovery parameters. The safety profile of OFA in hip surgery will also be assessed.

Discussion: Effective prevention of PND is crucial for optimizing postoperative recovery and long-term functional outcomes in elderly patients. This trial aims to refine and optimize anesthesia management strategies to reduce the incidence of PND, improve postoperative quality of life, and ultimately enhance perioperative neurocognitive outcomes.

Trial registration: This trial protocol was registered with the China Clinical Trial Registry on December 14, 2023, under the registration number: ChiCTR2300078647.