Intraoperative blood glucose levels in nondiabetic patients undergoing elective major surgery under general anaesthesia receiving different crystalloid solutions for maintenance fluid

CONTEXT: The study was undertaken to observe the effect of different maintenance-fluid regimen on intraoperative blood glucose levels in non-diabetic patients undergoing elective major non-cardiac surgery under general anesthesia. AIMS: To know the intraoperative blood glucose levels. SETTINGS AND DESIGN: Prospective randomized parallel group study. SUBJECTS AND METHODS: Two hundred non-diabetic patients (100 in each group) aged between 18 years and 60 years were enrolled for this prospective randomized parallel group study. Group A patients received Ringer's lactate solution and Group B patients received 0.45% sodium chloride with 5% dextrose and 20 mmol/L potassium chloride as maintenance fluid. Capillary blood glucose (CBG) level was measured immediately before initiation of intravenous fluid therapy and thereafter hourly till the end of surgery. If at any time intraoperative CBG was found to be more than or equal to 150 mg/dL calculated dose of human soluble insulin was given as intravenous bolus equal to the amount of CBG/100 units. STATISTICAL ANALYSIS USED: For comparison of normally distributed variables independent sample t test was done. For rest of the data, i.e., CBG_0, CBG_4 and insulin consumption Mann-Whitney U test was employed. RESULTS: 63% patients in group B developed at least one episode of hyperglycemia CBG ≥ 150 mg/dL) but only 29% in the Group A did so. Insulin consumption was significantly higher in Group B than in Group A to maintain normoglycemia. The relative risk of becoming hyperglycemic in Group B patients is 2.172 (95% CI 1.544 to 3.057). Number needed to harm, i.e., hyperglycemia, in Group B is 2.941 (95% CI 2 to 5). CONCLUSIONS: We conclude that stress induced-hyperglycemic response in patients undergoing major non-cardiac surgery is common in non-diabetic population. Maintenance-fluid therapy by dextrose containing solution as opposed to Ringer's lactate solution increases the incidence of hyperglycemia. To achieve normoglycemia by intravenous bolus dose of human regular insulin, significantly higher doses are required in patients receiving dextrose containing saline as maintenance fluid.