The use of peripheral nerve block decrease incidence of postoperative cognitive dysfunction following orthopedic surgery: A systematic review and meta-analysis

Background: Postoperative neurocognitive disorders (PNDs) frequently occur following orthopedic surgery and are closely associated with adverse prognosis. PNDs are an emerging concept that includes both postoperative cognitive dysfunction (POCD) and postoperative delirium (POD). The prevention of combined use of peripheral nerve block (PNB) and general anesthesia (GA) on POCD and/or POD incidence following orthopedic surgery remains unknown. We aimed to investigate the effect of this combined anesthesia method on POCD/POD incidence after orthopedic surgery, compared with GA.

Methods: The databases of PubMed, Web of Science, Embase via Ovid, and the Cochrane Central Register of Controlled Trials were searched for all available randomized controlled trials (RCTs). The incidence of POD/POCD was the primary outcome. Continuous and dichotomous outcomes are represented as standardized mean differences [SMD, 95% confidence interval (CI)] and risk ratios [RR, 95%CI], respectively.

Results: Meta-analysis of twelve RCTs with a total of 1488 patients revealed that compared with GA, PNB plus GA decreased the incidence of POCD (RR: 0.58, 95%CI: 0.35 to 0.95, P = 0.03, I² = 0%), while the incidence of POD had no significant difference (RR: 0.87, 95%CI: 0.54 to 1.40, P = 0.57, I² = 67%). Compared with GA alone, a significant decrease of intraoperative and postoperative opioid consumption (SMD: -1.54, 95%CI: -2.26 to -0.82, P < 0.0001, I² = 89%; SMD: -7.00, 95%CI: -9.89 to -4.11, P < 0.00001, I² = 99%) and postoperative nausea and vomiting incidence (RR: 0.16, 95%CI: 0.06 to 0.44, P = 0.0004, I² = 0%) was found with PNB plus GA.

Conclusions: The combined use of PNB and GA decreases the incidence of POCD but not POD following orthopedic surgery.

Trial registration: The protocol of this study was registered with PROSPERO (Registration Number: CRD42022366454).