Routine peri-operative management of the diabetic patient

Many aspects of peri-operative management of the diabetic patient remain controversial, although there are a variety of approaches towards management. These patients are at risk for certain complications related to the severity and chronicity of the disease. The surgeon and the anaesthetist must be conversant with the management of diabetes in elective and emergency situations. Reasonable metabolic control can be achieved within a few hours pre-operatively and clinical assessment can be performed on an out-patient basis. Anaesthetic management consists of assessment of the control of the disease followed by evaluation of diabetic complications and their severity. Different views are expressed regarding tight control of blood glucose level (4-8 mmol/l) versus moderate control (8-12 mmol/l) when managing diabetic patients. The importance of guarding against factors favouring metabolic decompensation in the peri-operative period, is stressed. Minor or major surgery has important implications regarding the management of diabetes. All patients scheduled for major surgery should be treated with intravenous insulin. Blood sugar should be monitored at regular intervals to protect the patient against hypoglycaemia. Emergency surgery is usually associated with an infectious process. Pronounced hyperglycaemia, dehydration and metabolic derangement may be present. The underlying pathology may aggravate the diabetic state and surgery may actually improve the patient's condition. It is unnecessary to postpone surgery to treat ketosis fully, because this may need 12-24 hours. Extreme insulin resistance and greater insulin requirements are present during cardiopulmonary bypass, hypothermia and rewarming. Beware of severe hypoglycaemia after cardiopulmonary bypass.