Clinical studies have shown that maintaining normal blood glucose level improves clinical outcomes in critically ill diabetic patients. There is general consensus that: • intensive insulin therapy with intravenous insulin, with the goal of maintaining blood glucose 80-110 mg/dl, reduces mortality among critically ill patients in the intensive care unit; • intravenous insulin infusion is safe and effective for achieving metabolic control during major surgery, haemodynamic instability and NPO status; • intravenous insulin infusion improves survival in patients after myocardial infarction and stroke; • in cases of DKA and HHS, regular insulin should be administered by means of continuous infusion in small doses through an infusion pump.