Are diabetic patients suitable candidates for ambulatory surgery?

Are diabetic patients suitable candidates for ambulatory surgery?

Diabetic patients may present a major challenge for the anesthesiologist when scheduled for ambulatory surgery. Because of the critical nature of glucose homeostasis, it may be advisable to handle exceptionally brittle diabetics on an inpatient basis. Preoperatively, diabetic patients must be carefully assessed for the presence of end-organ damage. Cardiovascular disease, autonomic and renal insufficiency, and gastroparesis may lead to potential problems in the perioperative period.

It is preferable to schedule surgery on the insulin-dependent diabetic as the first or second case of the day. The major concerns, of course, are to avoid the extremes of plasma glucose, both hypoglycemia and hyperglycemia, as well as acidosis. Delays in insulin administration may lead to ketoacidosis despite the fasting state. For this reason, it is recommended that patients receive insulin along with a continuous infusion of dextrose on arrival at the ambulatory surgery facility. Insulin may be administered by either the subcutaneous or intravenous route. The relative advantage, if any, of administering a continuous infusion of regular insulin versus one third to one half of the usual long-acting insulin dose subcutaneously has not been demonstrated. Another option for early-morning surgical procedures is to administer the usual long-acting insulin dose subcuta-neously immediately following surgery and shift the time of all meals and future insulin injections by the same offset.

Non-insulin-dependent diabetics who are controlled by one of the available oral hypoglycemic agents must also be carefully monitored in the perioperative period by periodic fingerstick or blood glucose determinations. The half-life of some of the oral agents may be as long as 60 hours (chlorpropamide). Fortunately, patients with adult-onset, non-insulin-dependent diabetes mellitus (NIDDM) rarely develop ketoacidosis. However, this group may develop hyperosmolar, nonketotic coma when significant hyper-glycemia and dehydration occur.

Before discharge, it is critical that diabetic patients be capable of eating and be relatively free of significant nausea that might lead to emesis and inability to maintain adequate caloric intake.