Acupuncture for post-operative cognitive dysfunction: a systematic review and meta-analysis of randomized controlled trials

Objective: Post-operative cognitive dysfunction (POCD) is a common post-surgical complication, which is associated with increased costs and extended hospital stays. Recently, interest in acupuncture as a potential therapy for POCD has grown. The objective of this meta-analysis was to assess the effectiveness of acupuncture for POCD. Methods: PubMed, Embase, CENTRAL, Medline, Web of Science, CNKI, Wanfang, and VIP databases were searched through March 2018. Randomized controlled trials (RCTs) in which patients with POCD treated with acupuncture (acupuncture group) were compared with those receiving a no treatment control were included. Meta-analyses were conducted using Review Manager 5.3. Results: Sixteen studies containing 1241 participants were included. POCD incidence in the acupuncture group was significantly lower than that in the control groups on the first (odds ratio (OR) = 0.32, 95% confidence interval (CI) = 0.23-0.45) and third (OR = 0.41, 95% CI = 0.30-0.56) post-operative days, with no statistically significant difference on the seventh day (OR = 0.58, 95% CI = 0.32-1.04). Acupuncture therapy also improved mini-mental state examination (MMSE) scores on the first (mean difference (MD) = 3.28, 95% CI = 2.79-3.77) and third (MD = 2.52, 95% CI = 2.18-2.87) post-operative days, with no effect on the seventh (MD = 0.14, 95% CI = -0.24 to 0.51). Visual analogue scale (VAS) scores on the first post-operative day were not impacted by acupuncture but were likely associated with post-operative nausea and vomiting on the seventh post-operative day. With respect to methodological quality, most RCTs were found to have an unclear risk of bias. Conclusion: Acupuncture may successfully treat/prevent POCD. However, the current evidence is limited and further research is needed.