Gan, Tong J.

Summary There are few data regarding postoperative hyperglycaemia in non‐diabetic compared with diabetic patients following postoperative nausea and vomiting prophylaxis with dexamethasone. Eighty‐five non‐diabetic patients and patients with type‐2 diabetes were randomly allocated to receive intravenous dexamethasone (8 mg) or ondansetron (4 mg). Blood glucose levels were measured at baseline and then 2, 4 and 24 h following induction of anaesthesia. In non‐diabetic patients, the mean ( SD ) maximum blood glucose was higher in those who received dexamethasone compared with ondansetron (9.1 (2.2) mmol.l −1 vs. 7.8 (1.4) mmol.l −1 , p = 0.04). In diabetic patients, the mean ( SD ) maximum blood glucose was also higher in those who received dexamethasone compared with ondansetron (14.0 (2.5) mmol.l −1 vs. 10.7 (2.4) mmol.l −1 , p < 0.01). Multivariate analysis demonstrated that dexamethasone administration was a significant predictor of maximum postoperative blood glucose increase (p < 0.01) after adjusting for potential confounders. There was no interaction between baseline blood glucose level, or presence or absence of diabetes, and dexamethasone administration. We conclude that dexamethasone increases postoperative blood glucose levels in both non‐diabetics and diabetics.

Background: Antiemetic guidelines recommend a combination of serotonin (5-HT 3 ) with a second agent such as droperidol or dexamethasone. Physicians have been reluctant to employ these guidelines due to concerns over the black-box warning of droperidol and safety concerns with a steroid. Objective: To assess the safety profiles of 5-HT 3 receptor antagonist (5-HT 3 RA) monotherapy and combination therapy with a steroid or droperidol for prophylaxis of postoperative nausea and vomiting (PONV). Methods: A MEDLINE search of English-language reports of randomized controlled trials (RCTs) was conducted (1966–September 2005) using the key terms 5-HT 3 , granisetron, ondansetron, dolasetron, tropisetron, PONV, postoperative, vomiting, emesis, and nausea. RCTs with treatment arms comparing 5-HT 3 RA monotherapy (granisetron, ondansetron, dolasetron, or tropisetron) with dexamethasone or droperidol or 5-HT 3 RA combinations and providing incidence data on adverse events were identified and reviewed. Within-study odds ratios with 95% confidence intervals were calculated to determine the incidence rates of all adverse events in RCTs using 5-HT 3 RA monotherapy and combination therapies. Overall effect sizes for frequently reported adverse events were estimated by pooling ORs using fixed- and random-effect models. Results: Pooled ORs (OR pooled ) for adverse events with 5-HT3RA/dexamethasone versus 5-HT 3 RA for PONV prophylaxis were not significant for any reported adverse events or the overall incidence of adverse events; 5-HT 3 RA/droperidol versus 5-HT 3 RA was significant only for decreased headache incidence (fixed model: OR pooled 0.35; 95% CI 0.18 to 0.69). The OR pooled for 5-HT 3 RA/dexamethasone versus dexamethasone was not significant for any reported adverse events except headaches (fixed model OR pooled 1.75; 95% CI 1.01 to 3.03), none of which was serious. OR pooled for 5-HT 3 RA/droperidol versus droperidol was not significant for any reported adverse events. Avascular necrosis, occult infection, and delayed wound healing were not observed with either combination therapy. Cardiac abnormalities were observed with 5-HT 3 RA/droperidol therapy. Conclusions: This meta-analysis indicates that either therapy has a safety profile similar to that of dexamethasone, droperidol, or 5-HT 3 RA.