Should Sodium-Glucose Linked Transporter 2 (SGLT2) inhibitors be stopped before surgery?

Perioperative Management of SGLT2 Inhibitors

SGLT2 inhibitors should be discontinued 3-4 days before elective surgery to reduce the risk of euglycemic diabetic ketoacidosis (euDKA). 1, 2

Rationale for Discontinuation

• The American Diabetes Association, American Heart Association, and American College of Cardiology all recommend discontinuing SGLT2 inhibitors 3-4 days before surgery with a Class 1 level of evidence (strong consensus) 1
• The FDA specifically warns that SGLT2 inhibitors should be stopped 3 days before scheduled surgeries (4 days in the case of ertugliflozin) 2
• SGLT2 inhibitors increase the risk of perioperative diabetic ketoacidosis (DKA), particularly euglycemic DKA, with a 48% higher risk compared to patients not taking these medications 1

Risk of Euglycemic DKA

• Euglycemic DKA is particularly dangerous because:
  • It can occur with near-normal blood glucose levels, making it difficult to detect 3
  • It can impose severe metabolic stress on the heart, potentially triggering myocardial ischemia and arrhythmias 4
  • Surgical stress, prolonged fasting, and metabolic changes are considered key triggers 3

Special Considerations

Emergency Surgery

• For patients on SGLT2 inhibitors requiring emergency surgery (where 3-4 day discontinuation is not possible):
  • Monitor ketone levels closely (blood ketone testing preferred over urine)
  • Maintain adequate hydration
  • Consider glucose-containing IV fluids to mitigate ketone generation 1
  • Be vigilant for signs of euDKA (nausea, vomiting, tachypnea, anion gap metabolic acidosis) even with normal glucose levels 1

Heart Failure Patients

• For patients taking SGLT2 inhibitors for heart failure:
  • There is emerging evidence that withholding SGLT2 inhibitors may worsen cardiovascular risk profile 5
  • However, the risk of euDKA remains significant and current guidelines still recommend discontinuation 1
  • More careful monitoring may be warranted if the decision is made to continue the medication in high-risk heart failure patients 1

Resuming SGLT2 Inhibitors Postoperatively

SGLT2 inhibitors should only be restarted when:

• The patient is eating and drinking normally (usually 24-48 hours after surgery)
• Capillary ketones are <0.6 mmol/L
• Renal function has been assessed and is stable
• No signs of acute illness or metabolic derangement are present 1

Common Pitfalls to Avoid

• Failure to recognize euDKA due to normal glucose levels
• Inadequate preoperative planning for medication discontinuation
• Restarting SGLT2 inhibitors too early in the postoperative period
• Not providing patients with written sick-day rules at discharge 1

Risk Factors Requiring Special Attention

• Renal insufficiency
• Dehydration
• Prolonged fasting
• Concomitant use of medications that affect renal function (ACE inhibitors, diuretics, NSAIDs) 1

Following these evidence-based guidelines for perioperative management of SGLT2 inhibitors can significantly reduce the risk of serious complications while ensuring optimal patient outcomes.