Effect of preoperative oral carbohydrate on perioperative blood glucose in Indian patients with type 2 diabetes mellitus scheduled for surgery under general anaesthesia - a randomized controlled study

Patients undergoing elective surgery are subjected to prolonged period of fasting in view of risk of pulmonary aspiration. Preoperative fasting state leads to a catabolic state, which adds to patient discomfort and delayed mobilization. Prolonged fasting and surgical trauma enhance the release of stress hormone, which leads to the development of hyperglycemia and insulin resistance (IR). Preoperative oral carbohydrate (POC) has shown beneficial effects in postoperative patient outcome and in decreasing hyperglycemia and IR. But, the effect of POC administration in Indian patients with Type 2 diabetes mellitus (DM) still remains inconclusive. Therefore, in this study we aim to see the effect of preoperative oral carbohydrate on perioperative blood glucose in Indian patients with Type 2 DM scheduled for surgery under general anaesthesia. The study will be conducted after obtaining approval from Institutional Ethics Committee-Human Research and written and informed consent. Patient will be asked to omit oral hypoglycemic agents as routinely done before surgery. Last meal time will be  noted for all the patients. An independent anaesthesiologist not involved in the further management of the patient will administer the carbohydrate drink/water as per group allocation based on a computer generated table of random numbers. Group A: Patients in this group will remain nil per orally for solids for at least 6 hours and will receive 296 ml drinking water 2 hrs before surgery. Group B: Patients in this group will remain nil per orally for solids for at least 6 hours and will receive 296 ml of oral carbohydrate solution containing 50g maltodextrin (Energizer-Neon laboratories) 2 hours before surgery. Patients will be taken inside the operating room where routine monitoring will be initiated. General anaesthesia will be given and the surgery will be allowed to proceed. Hourly glucose measurements will be done (capillary blood glucose). Blood samples will be collected for the estimation of serum insulin for the calculation of insulin resistance. Intraoperatively insulin will be administered as per Vellore regime to maintain blood glucose <180 mg/dL.