II. Evaluation: Preoperative
-
Cardiovascular Risk
- See Preoperative Cardiovascular Evaluation
- See Perioperative Cardiovascular Risk
- Preoperative stress testing is often indicated
- Assess for cardiac Autonomic Dysfunction
- Risk of perioperative Hypotension
- Features
- Resting Tachycardia
- Orthostatic Hypotension
- No variation in Heart Rate with respirations
- References
-
Renal Insufficiency (Diabetic Nephropathy)
- Renal Function tests
- Consider 24 Hour Urine Protein and Creatinine
III. Precautions: Fasting
- See Diabetes Sick Day Management
- Fasting is primarily prior to procedures or surgeries
- Patients may also wish to fast for religious reasons
- Break the fast for Hypoglycemia (especially Glucose <70 mg/dl, or symptoms and <80 mg/dl)
- Avoid Fasting in poorly controlled Diabetes Mellitus, pregnancy and acute illness
- Consider using perioperative guidelines below for holding diabetic medications for religious or other fasts
- Medications that rarely cause Hypoglycemia and may typically be continued when Fasting (consider holding for procedures)
- Metformin
- Typically held during perioperative period due to theoretical risk of Lactic Acidosis
- Pioglitazone
- Gliptins or DPP-4 Inhibitors (e.g. Januvia)
- Incretin Mimetic or GLP-1 Analogs (e.g. Victoza)
- Metformin
IV. Management: Medications to Hold When Perioperative or Fasting (Non-Insulin)
-
General
- Stop most Oral Hypoglycemic agents and other diabetic agents before surgery (or Fasting)
-
Sulfonylureas
- Hold long-acting Sulfonylureas 2-3 days before surgery
- Hold short-acting Sulfonylureas on the night before surgery (or up to 24-36 hours before a 24 hours fast)
-
Metformin
- Hold Metformin on day before surgery (risk of Lactic Acidosis)
-
Thiazolidinediones
- May be continued
-
Pramlintide (Symlin)
- Hold on the day of surgery
-
SGLT2 Inhibitor (Flozins)
- Hold SGLT2 Inhibitor 3 days before surgery and 2 days before procedures (or Fasting)
- Risk of Euglycemic Ketoacidosis
- Encourage adequate fluid intake (reduces risk of normoglycemic Ketoacidosis)
- May restart SGLT2 Inhibitor when hydrated and taking adequate oral intake
-
GLP1 Agonist (Incretin Mimetic)
- Hold daily GLP1 Agonists on the day of the procedure
- Hold weekly GLP1 Agonists (e.g. Semaglutide) starting 1 week prior to surgery
- Risk of Delayed Gastric Emptying and perioperative aspiration
- May resume postoperatively when taking adequate oral intake without Nausea or Vomiting
- Consider re-titrating GLP-1 dose if doses held for prolonged period
V. Management: Perioperative (or Fasting) Insulin
- Optimize Blood Sugar control prior to surgery
- Monitoring
- Check Blood Glucose every 2-4 hours perioperatively and Fasting
- Also obtain as needed for symptoms of Hypoglycemia
- Perioperative Blood Sugar Monitoring frequency per Anesthesia protocol
- Prefer perioperative mild Hyperglycemia to Hypoglycemia
- Target Blood Glucose 100 to 180 mg/dl until stable postoperatively
- Adjust postoperative Insulin based on oral intake
- Reduce overall Insulin 25% until oral intake improves
- Check Blood Glucose every 2-4 hours perioperatively and Fasting
-
Insulin
- Long acting Insulin (Insulin Glargine)
- Take 80 of the Insulin Glargine dose the night before the procedure
- Take 66-80% of the usual morning dose on the day of the procedure
- Take 50% of the usual morning dose if well controlled or Hypoglycemia risk (e.g. elderly, CKD)
- Reduce Tresiba (48 hour duration) dose the day before the procedure
- Intermediate Insulin (NPH Insulin)
- Take full NPH dose the night before the procedure
- Take 66% of the usual morning dose on the day of the procedure
- Mixed-Insulin (e.g. Insulin 70/30)
-
Insulin Pump
-
Insulin Pumps should only deliver basal rate (not bolus)
- Consider Running at 50% of the rate
- Anesthesia can adjust perioperatively
-
Insulin Pumps should only deliver basal rate (not bolus)
- Short-Acting, Rapid-acting or Bolus Insulin (e.g. Lispro, Regular, Aspart, Glulisine)
- Do not take Bolus Insulin (Short-Acting Insulin) on the morning of the procedure
- Long acting Insulin (Insulin Glargine)
- Consider Variable Rate Insulin Infusion (Insulin Drip) for postoperative Glucose control
- Preferred over use of Sliding Scale Insulin
VI. References
- (2024) Presc Lett 31(11): 62
- (2021) Presc Lett 28(9): 52
- Dummer (2009) Perioperative Guidelines
- Marks (2003) Am Fam Physician 67:93-100 [PubMed]