Electroacupuncture for the Prevention of Postoperative Cognitive Dysfunction Among Older Adults Undergoing Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Postoperative cognitive dysfunction (POCD) is a common surgical complication in elderly patients undergoing hip and knee replacement. Electroacupuncture (EA) may have a protective effect on postoperative cognitive function, but relevant evidence remains uncertain. Objective: To systematically evaluate the evidence of EA for the prevention of POCD after total joint arthroplasty. Methods: PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Infrastructure (CNKI), Wanfang Data, VIP, and Chinese Biomedical Literature Database (CBM) databases were searched until May 1, 2021. Randomized controlled trials (RCTs) in which patients undergoing hip and knee replacement pretreated with EA for preventing POCD were included. The risk of bias was assessed by the Cochrane Collaboration tool. Meta-analysis was performed using Review Manager version 5.4. Results: A total of 11 RCTs with 949 patients were identified. Meta-analysis showed that compared with controls, EA pretreatment significantly reduced the incidence of POCD at 1, 3, and 7 days and 3 and 6 months after the operation. EA was also superior in improving the Mini-Mental State Examination (MMSE) scores on the third postoperative day, but not on the first postoperative day. Neuron-specific enolase (NSE) and interleukin-1β (IL-1β) in the EA group were significantly lower than that in the control group. There was no difference in S100β between the EA group and the control group. Compared to the control group, tumor necrosis factor-α (TNF-α) levels were not significantly lower in the EA group at postoperative hour 0, while significantly decreased at postoperative hours 24 and 48. Conclusion: Our results suggest that EA pretreatment is an effective adjunctive therapy for reducing the incidence of POCD for patients receiving total joint replacement surgery. Its effect was embodied in improving the MMSE scores and NSE, IL-1β, and TNF-α levels, whereas it had no significant effect on S100β levels. Meanwhile, the benefits of EA for improving POCD need further strengthening and support from more large-scale, high-quality, and good-homogeneity RCTs. Systematic Review Registration: https://osf.io/xb3e8.