Randomised controlled trial of the effect of oral premedication with dexamethasone on hyperglycaemic response to abdominal hysterectomy.

ABSTRACT

BACKGROUND: This study was performed to evaluate the metabolic effects of a single oral dose of 8 mg dexamethasone in women undergoing hysterectomy. METHODS: Ninety non-diabetic women undergoing abdominal hysterectomy were randomised to receive 8 mg dexamethasone or placebo 2 h before surgery. Patients' perioperative care was standardised (fasting from midnight before surgery, balanced anaesthesia using propofol, fentanyl, remifentanil, cisatracurium, desflurane in oxygen/air). At five defined time points after drug administration (approximately 2, 4, 6, 10 and 14 h), blood samples were drawn under fasting conditions to measure blood glucose and free (non-esterified) fatty acids (NEFA). Data were analysed using analysis of variance for repeated measures. RESULTS: Data of 82 patients (dexamethasone 44 and placebo 38) were eligible for analysis. There was a statistically significant increase in blood glucose in both groups (P = 0.008). This increase was more pronounced in patients receiving dexamethasone (interaction term P = 0.02) with maximum values at 6 h after surgery (or approximately 10 h after dexamethasone administration). There were 36 patients (placebo 9 = 24% and dexamethasone 27 = 61%) presenting with elevated glucose concentrations (>7 mmol l⁻¹) and 11 patients (placebo 2 = 5% and dexamethasone 9 = 20%) with hyperglycaemia (>8.5 mmol l⁻¹). There were no statistically significant changes in the plasma concentrations of NEFA during the perioperative period. CONCLUSION: Amounts of dexamethasone frequently used for prophylaxis of post-operative nausea and vomiting can cause short-lasting hyperglycaemia in the post-operative period, but no relevant alterations in fat metabolism. Thus, the benefits of administering corticosteroids should be weighed against the potential side-effects of short-lasting hyperglycaemia.