How should insulin degludec (insulin degludec) be managed in a patient with diabetes (diabetes mellitus) who is taking insulin degludec and is scheduled for surgery?

Perioperative Management of Insulin Degludec

For patients on insulin degludec undergoing surgery, reduce the dose to 75-80% of the usual daily dose on the morning of surgery, hold all oral diabetes medications (metformin on day of surgery, SGLT2 inhibitors 3-4 days prior), and monitor blood glucose every 2-4 hours while NPO with short-acting insulin correction as needed. 1, 2

Preoperative Medication Management

Insulin Degludec Dosing

• Administer 75-80% of the usual daily dose of insulin degludec on the morning of surgery 1, 2
• This dose reduction applies to all long-acting basal insulin analogs, including degludec 1, 2
• The 2025 ADA guidelines specifically recommend this 75-80% dosing for long-acting analogs, which is more conservative than the older 60-80% range 1
• A 25% reduction (giving 75% of usual dose) the evening before surgery has been shown to achieve better perioperative glucose control with decreased hypoglycemia risk compared to usual dosing 1

Oral Diabetes Medications

• Hold metformin on the day of surgery 1, 2
• Discontinue SGLT2 inhibitors 3-4 days before surgery due to euglycemic ketoacidosis risk 1, 2
• Hold all other oral hypoglycemic agents the morning of surgery 1, 2

Perioperative Glucose Targets and Monitoring

Target Blood Glucose Range

• Maintain blood glucose between 100-180 mg/dL (5.6-10.0 mmol/L) in the perioperative period 1, 2
• Stricter targets (tighter than 80-180 mg/dL) do not improve outcomes and significantly increase hypoglycemia risk 1

Monitoring Frequency

• Check blood glucose at least every 2-4 hours while the patient is NPO 1, 2
• Administer short- or rapid-acting insulin as needed for hyperglycemia 1, 2
• Do not use CGM alone for glucose monitoring during surgery 1

Preoperative Assessment Requirements

• Perform preoperative risk assessment for patients at high risk for ischemic heart disease, autonomic neuropathy, or renal failure 1, 2
• Target A1C <8% for elective surgeries whenever possible 1, 2
• Some institutions have A1C cutoffs for elective procedures and optimization programs to lower A1C prior to surgery 1

Special Considerations for Insulin Degludec

Unique Pharmacologic Properties

• Insulin degludec has an ultra-long duration of action extending beyond 24 hours with a peakless profile 3, 4
• The extended half-life means degludec provides more stable basal coverage but also requires careful dose reduction to prevent perioperative hypoglycemia 5
• Unlike shorter-acting insulins, degludec's prolonged action necessitates the 75-80% dose reduction rather than holding it entirely 1, 2

Administration Guidelines

• Do NOT administer insulin degludec intravenously or via insulin infusion pump 5
• Do NOT dilute or mix insulin degludec with any other insulin or solution 5
• Continue subcutaneous administration as usual on the morning of surgery at the reduced dose 1, 2

Postoperative Management

• Continue monitoring blood glucose every 2-4 hours until oral intake resumes 1, 2
• Resume usual insulin degludec dosing once the patient has stable oral intake 1
• Use basal-bolus regimen (basal insulin plus premeal rapid-acting insulin) rather than sliding scale alone for better glycemic control and reduced complications 1

Critical Pitfalls to Avoid

• Never give the full usual dose of insulin degludec on the day of surgery - the 75-80% reduction is essential to prevent hypoglycemia during the NPO period and surgical stress response 1, 2
• Never forget to discontinue SGLT2 inhibitors 3-4 days before surgery - failure to do so can lead to life-threatening euglycemic diabetic ketoacidosis 1, 2
• Never rely on sliding scale insulin alone - this approach leads to worse outcomes compared to scheduled basal-bolus regimens 1
• Never hold insulin degludec entirely - unlike NPH (which is reduced to 50%), long-acting analogs like degludec should be continued at 75-80% to maintain basal coverage 1