Effects of dexamethasone on postoperative cognitive dysfunction and delirium in adults following general anesthesia: a meta-analysis of randomized controlled trials

Abstract

Background Several studies have investigated the effects of dexamethasone on postoperative cognitive dysfunction (POCD) or postoperative delirium (POD); however, their conclusions have not been consistent. So we conducted a meta-analysis to determine the effects of dexamethasone on POCD/POD in adults following general anesthesia. Methods Cochrane Central Register of Controlled Trials (CENTRAL, 2018, Issue 11 of 12) in the Cochrane Library (searched November 17, 2018); MEDLINE OvidSP (1946 to November 16, 2018); and Embase OvidSP (1974 to November 16, 2018) were searched for randomized controlled trials that evaluated the incidence of POCD/POD following dexamethasone administration, in adults (age ≥18 years) under general anesthesia. We used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework to assess the quality of evidence. Results Five studies were included (three studies/855 participants in dexamethasone group and 538 participants in placebo group for the incidence of POCD, and two studies/410 participants in dexamethasone group and 420 participants in placebo group for the incidence of POD). There was no significant difference between the dexamethasone group and the placebo group in terms of the incidence of POCD in 30 days after surgery (RR 1.00; 95% CI [0.51, 1.96], P = 1.00, I2 = 77%) or in the incidence of POD (RR 0.96; 95% CI [0.68, 1.35], P = 0.80, I2 = 0%). However, both analyses had some limitations since evidence remains limited and clinical heterogeneity, and we considered the quality of the evidence for the postoperative incidence of POCD and POD to be very low. Conclusions This meta-analysis revealed that prophylactic dexamethasone did not reduce the incidence of POCD and POD. Trials of alternative prevent strategies for POCD/POD, and a better understanding of the pathophysiology of those complex syndrome, are still needed to make progress of this field. Trial registration number: This study is registered with PROSPERO, 23 October 2018, number CRD42018114552.