Introduction

The incidence of diabetes continues to increase over the last three decades, and its association with obesity is well established. Diabetes has been reported in 6 of 15 (40%) morbidly obese patients. Another larger study documented an incidence of type 2 diabetes mellitus (DM) of 20% in morbidly obese patients. The peri-operative care of the diabetic patient is important on two levels for the anesthesiologist. First, it is important to avoid major complications, for example hypoglycemia, hyperglycemic hyperosmolar state (HHS), diabetic ketoacidosis (DKA), and second, to also improve surgical outcomes. Tighter blood glucose control has been associated with improved outcome in diabetic patients.

Diabetes has recently undergone new nomenclature in order to eliminate the confusion caused by non-insulin and insulin-dependent diabetes mellitus (NIDDM vs. IDDM). This has had little relevance to the peri-operative management of diabetes, since virtually all patients are best managed with insulin. The new terms type 1 (pancreatic β-cell destruction) and type 2 (defective insulin secretion and, usually, insulin resistance) speak more clearly to the pathology rather than the treatment. The most important clinical distinction of these two types is that type 1 patients are prone to lipolysis, proteolysis, and ketogenesis → DKA. In type 2 patients, some amounts of insulin inhibit these processes, so that DKA usually does not occur unless there is an additional stress (for example sepsis or dehydration).