Intraoperative Dexamethasone and Delirium After Cardiac Surgery: A Randomized Clinical Trial

BACKGROUND: Delirium is common after cardiac surgery and may be partly related to the systemic inflammatory response triggered by the surgery and the use of cardiopulmonary bypass. We hypothesized that intraoperative administration of high-dose dexamethasone, a drug with potent anti-inflammatory effects, would reduce the incidence of delirium at any time point during the first 4 postoperative days after cardiac surgery. METHODS: This was a single-center substudy within a larger, multicenter placebo-controlled randomized clinical trial, the Dexamethasone for Cardiac Surgery (DECS) trial that randomized patients >= 18 years, undergoing cardiac surgery with cardiopulmonary bypass, to receive, in a double-blind fashion, either dexamethasone 1 mg/kg or placebo at the induction of anesthesia. Over the first 4 postoperative days, we compared between groups the incidence of delirium (based on the Confusion Assessment Method adapted for the intensive care unit, or after intensive care unit discharge, by the Confusion Assessment Method, accompanied by chart review), restraint use, and administered haloperidol, benzodiazepines, and opioids. Data were analyzed according to the intention-to-treat principle. The proportion of patients with delirium in the dexamethasone versus the placebo group was compared using the odds ratio (OR) with a 95% confidence interval (CI). The proportion also was compared using logistic regression to adjust for common baseline variables that might confound the presence of delirium between the 2 groups. RESULTS: Of 768 eligible patients, 737 subjects (96.0%) had complete data. The incidence of delirium was similar between the dexamethasone (14.2%) and placebo (14.9%) groups (crude OR = 0.95, 95% CI, 0.63-1.43; adjusted OR = 0.85, 95% CI, 0.55-1.31). Among patients who developed delirium, the median (interquartile range) duration of delirium was similar between the dexamethasone and placebo groups (2 [1-3] vs 2 [1-2] days, respectively, P = 0.45; WMWodds 0.98, 95% CI, 0.83-1.17). Restraint use and the administration of haloperidol, benzodiazepines, and opioids were also similar between the 2 groups. CONCLUSIONS: The intraoperative administration of dexamethasone did not reduce the incidence or duration of delirium in the first 4 days after cardiac surgery.