The effect of intraoperative dexamethasone on glycaemic responses in people with diabetes mellitus: a preplanned analysis of the Perioperative ADministration of Dexamethasone and Infection trial

BACKGROUND: The Perioperative ADministration of Dexamethasone and Infection (PADDI) randomised placebo-controlled trial showed that a single 8 mg dose of intraoperative dexamethasone had no effect on surgical-site infection within 30 days after nonurgent, noncardiac surgery. Whether dexamethasone increases blood glucose and adverse outcomes in people with diabetes mellitus remains unclear. METHODS: In this preplanned sub-study, 1130 PADDI participants (mean age 65.2 y: 40.7% female) with diabetes mellitus and glycated haemoglobin <9.0% were included in this 'as treated' analysis. The primary outcome was the maximum recorded perioperative blood glucose concentration (mM) within 24 h of anaesthesia induction. RESULTS: The maximum perioperative blood glucose level was 12.5 mM (median, IQR 10.6-15.0) in 570 participants receiving dexamethasone, compared with 10.3 mM (8.8-12.4) in 560 participants receiving placebo (estimated difference 1.86 mM (95% CI 1.50-2.22), P<0.001). There was no evidence of increased risk of surgical-site infection (dexamethasone 11.1% vs placebo 14.4%, risk ratio [RR], 0.74; 95% confidence interval [CI], 0.54-1.01). Age, sex, BMI and HbA1c were not associated with maximum perioperative glucose levels or the incidence of surgical-site infections between the dexamethasone and placebo groups. The requirement for additional insulin and the number of hypoglycaemic episodes did not differ between groups. CONCLUSION: In people with diabetes mellitus, dexamethasone was associated with a modest increase in perioperative blood glucose but not with increased surgical-site infection. These findings support the use of dexamethasone to prevent postoperative nausea and vomiting in people with diabetes mellitus.