What is the perioperative management of diabetes medications?

Updated: Jan 09, 2018
  • Author: Nafisa K Kuwajerwala, MD; Chief Editor: William A Schwer, MD  more...
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Patients with diabetes are at higher risk for perioperative complications. In a study of 1042 patients who underwent total hip replacement, researchers compared the incidence rate of postoperative infection in persons with diabetes (11%) and in persons without diabetes (2%). This increased incidence rate may be accounted for by delayed wound healing or an alteration in leukocyte function in patients with poorly controlled diabetes.

Diabetes is a predictor of cardiac morbidity in patients undergoing vascular surgery. adequate glycemic control is essential prior to an elective surgery. The blood glucose level on the morning of surgery ideally should be lower than 200 mg. Postpone elective surgery in patients who have glucose levels greater than 300 mg. For emergency surgery, achieve optimal control rapidly, and direct attention toward optimization of volume status.

The primary goal of perioperative control is to avoid ketosis and to maintain glucose levels of 100-200 mg/dL. If the procedure is short and can be performed early in the morning and the patient is expected to eat shortly after the procedure, then the patient's diabetic regimen can be shifted to a few hours later in the day.

Persons with type 1 diabetes always require insulin perioperatively, even if the addition of glucose is needed to allow the administration of insulin without hypoglycemia. Persons with type 2 diabetes require insulin perioperatively, especially if their diabetes is usually controlled with insulin and they are undergoing major surgery. Administer insulin either subcutaneously at approximately 50% of the patient's usual morning human insulin isophane suspension dose on the morning of surgery or by an intravenous infusion at approximately 1 U/h. To avoid hypoglycemia, dextrose must be given along with insulin while the patient is not eating or drinking (ie, while NPO). Restart the usual regimen when patient is eating.

Monitor serum glucose levels every 1-2 hours during surgery and every 2-4 hours while NPO, then administer supplemental short-acting insulin as dictated by the blood sugar level. In states of peripheral vasoconstriction in which the subcutaneous compartment is suboptimally perfused, intravenous insulin administration (either bolus or infusion) ensures more controlled and effective tissue delivery than subcutaneous administration.

For patients controlled on oral agents, discontinue drugs 1 day before surgery. Discontinue biguanides (metformin) on the day of surgery because alterations in renal function arising intraoperatively may potentiate the risk of the patient developing lactic acidosis. Sulfonylureas are routinely continued on the day before surgery and withheld on the operative day.

Measure glucose levels every 4 hours. Regular insulin can be administered as needed to patients with glucose levels greater than 250 mg/dL. Resume the oral agent when patients return to their baseline diet. For patients undergoing outpatient surgery, reinstitute their preoperative regimen when they resume eating.

A study by Garg et al that included 3909 diabetes patients undergoing surgery who had preoperative and inpatient diabetes management reported improved glycemic control on the surgical date and decreased hypoglycemia incidence postoperatively. On the day of surgery, mean blood glucose was 146.4 ± 51.9 mg/dL before and 139.9 ± 45.6 mg/dL after the program (P = 0.0028). [11]

Table 3. Perioperative Medication Management for Patients With Diabetes and Hypothyroidism (Open Table in a new window)


Day Before Surgery

Day of Surgery

During Surgery

After Procedure

Oral hypoglycemics

Usual dose

Omit dose

Insulin (SC or IV)

Insulin until patient is no longer NPO


Usual dose

Omit dose

Insulin (SC or IV)

Usual dose


Usual dose

Usual dose on morning of surgery with sip of water


Restart the dose when patient is no longer NPO

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