The Efficacy of Anti-Inflammatory Medication in Postoperative Cognitive Decline: A Meta-Analysis

Objective: Post-operative cognitive decline is a surgical complication involving chronic impairments in different cognitive domains. Although the exact mechanisms behind postoperative cognitive decline are still unknown, there is increasing evidence for a key role of neuroinflammation. This meta-analysis aims to investigate the efficacy of anti-inflammatory treatment on postoperative cognitive decline. Participants and Methods: An electronic search was performed using PubMed, Psychinfo, EmBase, Cochrane Database of Systematic Reviews and clinicaltrial.gov (until November 2019). No year or language restrictions were applied. Only randomized, double-blind, placebocontrolled studies that investigated clinical outcome in adult patients who underwent surgery under general anaesthesia (except brain surgery) were included. The search yielded 574 papers, of which nineteen fulfilled the inclusion criteria. Results: The current meta-analysis found a significant effect of different anti-inflammatory agents on the incidence of POCD (OR=0.67, p=0.010). Administration of COX-2 inhibitors (OR=0.31, p<0.0001), ketamine (OR=0.44, p=0.38) and lidocaine (OR=0.79, p=0.33) showed better results than placebo in a meta-analysis of at least two studies. Erythromycin (OR=0.14, p=0.006), erythropoietin (OR=0.15, p=0.07) and dexmedetomidine (OR=0.58, p=0.03) were significant in single studies. No beneficial effects on cognition were found for magnesium, 17β- estradiol, dexamethasone and melatonin. Conclusion: The results of this meta-analysis provide evidence for a potential efficacy of anti-inflammatory agents on POCD, but further research is necessary to determine which agents are most appropriate for clinical application.