Melatonin and its analogues for the prevention of postoperative delirium: A systematic review and meta-analysis

Abstract

It remains unclear whether melatonin and its analogues prevent postoperative delirium (POD). Therefore, we conducted a systematic review and meta-analysis to evaluate the effect of melatonin and its analogues on POD prevention. PubMed, Cochrane Library, Web of Science, Embase and CINAHL databases were searched. Primary outcome was the incidence of POD. Six randomized controlled trials, 2 cohort studies and 1 case-control study were included in this meta-analysis. Results showed that melatonin and its analogue ramelteon decreased the incidence of POD in the entire adult surgical population (odds ratio [OR] = 0.45, 95% confidence interval [CI] 0.24-0.84, P =.01). When administered at a higher dose (5 mg), melatonin was effective in reducing the POD incidence (OR = 0.32, 95% CI 0.20-0.52, P