New insulin analogues and perioperative care of patients with type 1 diabetes

While insulin remains the mainstay of managing type 1 diabetes, much has changed over the last 15 years. These changes should help in managing patients with type 1 diabetes during the perioperative period. More flexible insulin therapy has three components: (1) basal, (2) prandial and (3) corrective. Many patients, particularly younger patients, are using genetically modified recombinant human insulin analogues. Two of these analogues, aspart and lispro insulin, are rapid-acting with faster onset and offset than subcutaneous regular insulin, allowing both prandial and corrective boluses. Other insulin analogues, particularly glargine and possibly detemir have a flat profile of up to 24 hours, providing improved basal insulin delivery. Basal insulin can also be provided by a continuous subcutaneous infusion of rapid-acting insulin via a computerised pump that also provides boluses on demand. There is little evidence to help choose the best management of patients with type 1 diabetes during surgery. Some authors still recommend glucose-potassium-insulin infusions for all patients with type 1 diabetes. We challenge this approach, given the flexibility of the newer insulin analogues and delivery systems. We suggest that for many procedures, patients' usual regimens can be maintained in the perioperative period, providing less disruption and, possibly, greater safety. Both hyperglycaemia and hypoglycaemia reflect poor management: we suggest a target glucose range of 5 to 10 mmol/l. The importance of frequently measuring blood glucose and appropriate responses cannot be overemphasised.