The association between peripheral nerve blocks and postoperative delirium in adults undergoing hip fracture surgery: a systematic review and meta-analysis.

Abstract

Objective: To review and synthesise the existing evidence on the effects of peripheral nerve block (PNB) compared with no nerve block on the incidence of postoperative delirium (POD) in adults undergoing hip fracture repair.

Methods: A systematic search of electronic databases (PubMed, Web of Science, EMBASE, and the Cochrane Library) for relevant literature published from database inception to 1st May 2025 was conducted. Randomised controlled trials with PNBs as an intervention in adults undergoing surgery for hip fractures were selected. Studies that excluded patients with preoperative cognitive dysfunction and observed POD as an outcome were eligible.

Results: Twelve randomised controlled trials, involving a total of 1157 participants, 602 in the control group and 555 in the intervention, were included for quantitative analysis. The meta-analysis revealed that PNBs significantly reduced the incidence of POD (RR: 0.68, 95% CI [0.50 to 0.91], P = 0.009, I² = 43%).

Conclusion: In patients without pre-existing cognitive impairment, the perioperative use of PNBs can reduce the occurrence of POD. However, substantial variation in study design and heterogeneity of PNB approaches limit the certainty of these findings. Future research calls for well-designed, standardised, and stratified clinical trials to compare the efficacy of each PNB approach and to evaluate their potential benefits in those at greater risk of POD, including those with baseline cognitive impairment and preoperative delirium. Video Abstract.