Impact of Intraoperative Dexamethasone on Perioperative Blood Glucose Levels: Systematic Review and Meta-Analysis of Randomized Trials

BACKGROUND: Dexamethasone is associated with increased blood glucose levels that could impact patient outcomes or management. This study aimed to synthesize the available evidence regarding the impact of an intraoperative single dose of dexamethasone on blood glucose levels. METHODS: We searched CENTRAL, MEDLINE, and clinicaltrials.gov for randomized controlled trials (RCTs) comparing a single intraoperative dose of dexamethasone to control in adult patients who underwent noncardiac surgery. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the review was registered in PROSPERO (CRD42023420562). Data were pooled using a random-effects model. We reported pooled dichotomous data using odds ratios (OR) and continuous data using the mean difference (MD), reporting 95% confidence intervals (95% CIs), and corresponding P-values for both. Confidence in the evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. As primary outcomes we assessed maximum blood glucose levels measurement and variation from baseline within 24 hours of surgery; blood glucose levels measurement and variation from baseline at 2, 4, 8, 12, and 24 hours after dexamethasone administration. As secondary outcomes, we evaluated insulin requirements and hyperglycemic events. RESULTS: We included 23 RCTs, enrolling 11,154 participants overall. Dexamethasone was associated with a significant increment in blood glucose levels compared to control at all timepoints. The results showed an increase compared to control of 0.37 mmol L-1 (6.7 mg dL-1) at 2 hours (95% CI, 0.16-0.58 mmol L-1 or 2.9-10.5 mg dL-1), 0.97 mmol L-1 (17.5 mg dL-1) at 4 hours (95% CI, 0.67-1.25 mmol L-1 or 12.1-22.5 mg dL-1), 0.96 mmol L-1 (17.3 mg dL-1) at 8 hours (95% CI, 0.55-1.36 mmol L-1 or 9.9-24.5 mg dL-1), 0.90 mmol L-1 (16.2 mg dL-1) at 12 hours (95% CI, 0.62-1.19 mmol L-1 or 11.2-21.4 mg dL-1) and 0.59 mmol L-1 (10.6 mg dL-1) at 24 hours (95% CI, 0.22-0.96 mmol L-1 or 4.0-17.3 mg dL-1). No difference was found between subgroups regarding diabetic status (patients with diabetes versus patients without diabetes) in all the outcomes except 2 (maximum blood glucose levels variation within 24 hours and variation at 4 hours) and dexamethasone dose (4-5 mg vs 8-10 mg) in all the outcomes except 2 (blood glucose levels at 24 hours and hyperglycemic events). CONCLUSIONS: Mean blood glucose levels rise between 0.37 and 1.63 mmol L-1 (6.7 and 29.4 mg dL-1) within 24 hours after a single dose of dexamethasone administered at induction of anesthesia compared to control, but in most patients this difference will not be clinically relevant.