Perioperative Diabetes Management

1. See Also
   1. Preoperative Examination
   2. Deep Vein Thrombosis Prevention
   3. Perioperative Anticoagulation
   4. Endocarditis Prophylaxis
   5. Postoperative Nausea and Vomiting Prevention
   6. Diabetes Sick Day Management
2. Evaluation: Preoperative
   1. Cardiovascular risk
      1. See Preoperative Cardiovascular Evaluation
      2. See Perioperative Cardiovascular Risk
      3. Preoperative stress testing is often indicated
      4. Assess for cardiac Autonomic Dysfunction
         1. Risk of perioperative Hypotension
         2. Features
            1. Resting Tachycardia
            2. Orthostatic Hypotension
            3. No variation in Heart Rate with respirations
         3. References
            1. Burgos (1989) Anesthesiology 70:591-7 [PubMed]
   2. Renal Insufficiency (Diabetic Nephropathy)
      1. Renal Function tests
      2. Consider 24 Hour Urine Protein and Creatinine
3. Precautions: Fasting
   1. See Diabetes Sick Day Management
   2. Fasting is primarily prior to procedures or surgeries
   3. Patients may also wish to fast for religious reasons
      1. Break the fast for Hypoglycemia (especially Glucose <70 mg/dl, or symptoms and <80 mg/dl)
      2. Avoid Fasting in poorly controlled Diabetes Mellitus, pregnancy and acute illness
   4. Consider using perioperative guidelines below for holding diabetic medications for religious or other fasts
   5. Medications that rarely cause Hypoglycemia and may typically be continued when Fasting (consider holding for procedures)
      1. Metformin
         1. Typically held during perioperative period due to theoretical risk of Lactic Acidosis
      2. Pioglitazone
      3. Gliptins or DPP-4 Inhibitors (e.g. Januvia)
      4. Incretin Mimetic or GLP-1 Analogs (e.g. Victoza)
4. Management: Perioperative (or Fasting) Blood Sugar control
   1. Optimize Blood Sugar control prior to surgery
   2. Monitoring
      1. Check Blood Glucose every 4 hours prior to surgery and as needed for symptoms of Hypoglycemia
      2. Perioperative Blood Sugar Monitoring frequency per Anesthesia protocol
      3. Prefer perioperative mild Hyperglycemia to Hypoglycemia
   3. Insulin
      1. Long acting Insulin (Lantus, Levemir)
         1. Take full Lantus dose the night before the procedure
         2. Take 66-80% of the usual morning dose on the day of the procedure
            1. Take 50% of the usual morning dose if well controlled or Hypoglycemia risk (e.g. elderly, CKD)
         3. Reduce Tresiba (48 hour duration) dose the day before the procedure
      2. Intermediate Insulin (NPH Insulin)
         1. Take full NPH dose the night before the procedure
         2. Take 66% of the usual morning dose on the day of the procedure
      3. Mixed-Insulin (e.g. Insulin 70/30)
         1. Do not take mixed Insulin on the morning of surgery
         2. Give NPH at 66% of the usual morning dose (NPH component only of the mixed Insulin) on the day of the procedure
            1. Calculate the usual NPH dose from the mixed Insulin
      4. Insulin Pump
         1. Insulin Pumps should only deliver basal rate (not bolus)
            1. Consider Running at 50% of the rate
         2. Anesthesia can adjust perioperatively
      5. Short-Acting, Rapid-acting or Bolus Insulin (e.g. Lispro, Regular, Aspart, Glulisine)
         1. Do not take Bolus Insulin (Short-Acting Insulin) on the morning of the procedure
   4. Consider Variable Rate Insulin Infusion (Insulin Drip) for postoperative Glucose control
      1. Preferred over use of Sliding Scale Insulin
   5. Stop Oral Hypoglycemic agents and other diabetic agents before surgery (or Fasting)
      1. Hold long-acting Sulfonylureas 2-3 days before surgery
      2. Hold short-acting Sulfonylureas on the night before surgery (or up to 24-36 hours before a 24 hours fast)
      3. Hold Metformin on day before surgery (risk of Lactic Acidosis)
      4. Hold Byetta, Symlin on the day of surgery
      5. Hold Flozins and encourage adequate fluid intake (reduces risk of normoglycemic Ketoacidosis)
      6. Thiazolidinediones may be continued
      7. Hold SGLT2 Inhibitor 3 days before surgery and 2 days before procedures (or Fasting if risk of Dehydration)
5. References
   1. (2021) Presc Lett 28(9): 52
   2. Dummer (2009) Perioperative Guidelines
   3. Marks (2003) Am Fam Physician 67:93-100 [PubMed]