About 21 million adults have diabetes in the United States, and 5.5 million hospital discharges include diabetes as one of the listed diagnoses. Annual inpatient health care costs directly related to diabetes were estimated at $76 billion in 2012. People with diabetes have a higher lifetime probability of requiring surgery compared to the general population due to increased cardiovascular, ophthalmic, renal, and neuropathic complications from their disease. Diabetes mellitus itself may complicate surgical wound healing and recovery. Surgical site infections may be twice as high in patients with diabetes, potentially from small vessel disease impairing oxygen and nutrient delivery to tissues, impaired leukocyte and monocyte function due to hyperglycemia, and decreased release of neuropeptides in those with peripheral neuropathy. Patients with diabetes also have higher postoperative in-hospital mortality compared to those without diabetes. Patients with higher postoperative blood sugars after coronary bypass surgery have an increased rate of complications. Surgery and anesthesia provoke release of counter-regulatory hormones, which cause hyperglycemia and increased catabolism. Care for the surgical patient with diabetes should focus on avoidance of marked hyperglycemia, which can alter wound healing and disrupt fluid balance, while also avoiding hypoglycemia, which can cause cardiac stress. Perioperative evaluation for patients with diabetes allows for the development of an individualized plan to reduce perioperative complications and to determine a safe and effective diabetes discharge plan.
A thorough history remains a key component in the preoperative evaluation of the patient with diabetes. A history of comorbidities and complications associated with diabetes may provide additional insight into surgical risk, and therefore perioperative management. For example, elective surgery should be delayed in patients with diabetes after a recent cardiac event (see Chapter 50: Preoperative Cardiac Risk Assessment and Perioperative Management). Patients with concomitant renal disease need to be monitored carefully, with precautions to avoid contrast materials and other nephrotoxic agents. Diabetic autonomic neuropathy may predispose patients to perioperative hypotension. Gastroparesis with impaired gastric emptying may predispose patients to aspiration during intubation and extubation.
Clarification of the patient’s home diabetes regimen and assessment of their home glycemic control and adherence will help guide perioperative management. Ideally, patients will have good glycemic control prior to undergoing elective surgery, but this will not always be possible. Some experts advocate delaying elective surgery if the patients HbA1C is >8.5%, but there is no good literature to support or negate this practice. In addition, the management plan should take into consideration the patients’ typical diet and activity, which may change drastically in the perioperative period. The type and duration of surgery is also important to consider, as longer surgeries and recovery times (including ICU admission or prolonged NPO status) will affect the perioperative glycemic management plan.
Specific physical exam components for patients with diabetes should include inspection of injection sites or insulin pump infusion sites (if applicable) for evidence of lipohypertrophy, which may affect insulin absorption. ...