SURGERY IN PATIENTS WITH DIABETES

There are more than 140 million people with diabetes in the world. Iran’s share is estimated at 1.5 million people. The increasing prevalence of diabetes and the longer life expectancy of diabetic patients mean that an increasing number of patients with diabetes are undergoing surgery, and not just for diabetes and its complications, such as end-stage renal disease, retinopathy, peripheral vascular disease, and diabetic foot ulcers. The metabolic stress caused by general anaesthesia and the operation itself makes blood glucose control even more difficult. Stricter pre- and intra-operative glycaemic control reduces the risk of sepsis, cardiovascular events, disability and death, accelerates wound healing and decreases hospital stay. Improved outcome requires pre-operative ascertainment of the type of diabetes, quality of metabolic control, and detection of complications, as well as optimal metabolic and haemodynamic management during the operation. Local anaesthesia is the preferred option in this group of patients because it least interferes with metabolic control. The diet recommended to achieve normoglycaemia will depend on the type of diabetes, pre-operative glycaemic control, and the extent of the planned procedure. In all type 1 diabetic patients and type 2 diabetic patients on insulin or oral hypoglycaemic agents who are to undergo surgery under general anaesthesia, the glucose-insulin-potassium (GIK) regimen is the one recommended by most authors to achieve tight intra-operative blood glucose control, conditional upon blood glucose measurements being available every one or, at most, two hours. Intra-operative blood glucose levels in the 120-180mg/dl ranges are considered satisfactory. Failing this, it is recommended that 50% of the daily NPH requirement be given subcutaneously on the morning of the operation, together with an intravenous glucose infusion intra-operatively. Type 2 diabetic patients with unsatisfactory metabolic control, time permitting, should be admitted several days before the operation and switched to and stabilised on insulin.