Yes, Blood Glucose Monitoring is Mandatory on the Day of Surgery for Patients on Farxiga
You must check blood glucose at least every 2-4 hours on the day of surgery for any patient who has been taking Farxiga (dapagliflozin), starting from when they are NPO (nothing by mouth) and continuing throughout the perioperative period. 1
Critical Context: Farxiga Must Be Stopped 3-4 Days Before Surgery
Before addressing monitoring, it's essential to understand that SGLT2 inhibitors like Farxiga should be discontinued 3-4 days before surgery 1, 2, 1, 3, 2. This is a firm recommendation across all major guidelines to reduce the risk of perioperative ketoacidosis, which can be life-threatening 3, 4.
Why This Matters Even If the Drug Was Stopped
Even when Farxiga has been appropriately discontinued 3-4 days prior, blood glucose monitoring remains essential because:
- Surgical stress and counterregulatory hormones increase hyperglycemia risk, which is associated with increased mortality, infection, and length of stay 1
- The patient still has diabetes (or heart failure) requiring glycemic management
- Target blood glucose in the perioperative period is 100-180 mg/dL (5.6-10.0 mmol/L) 1
Specific Monitoring Protocol on Day of Surgery
Frequency: Check blood glucose at minimum every 2-4 hours while the patient is NPO 1
Treatment: Dose with short- or rapid-acting insulin as needed to maintain target range of 100-180 mg/dL 1
Important caveat: Do NOT use continuous glucose monitoring (CGM) alone during surgery—point-of-care blood glucose testing is required 1
Additional Perioperative Considerations
If Farxiga Was NOT Stopped Appropriately
If you discover the patient took Farxiga on or near the day of surgery (as occurred in the case report 4):
- Heightened vigilance for ketoacidosis is critical, even with normal or low blood glucose (euglycemic ketoacidosis)
- Check ketones in addition to glucose monitoring
- This can occur even in non-diabetic patients taking SGLT2 inhibitors for heart failure 4
- Ensure adequate hydration with IV fluids
Insulin Management on Day of Surgery
For patients previously on insulin:
- Give one-half of NPH dose or 75-80% of long-acting analog insulin the morning of surgery 1
- Consider reducing basal insulin by 25% the evening before surgery to lower hypoglycemia risk while maintaining target glucose 1
- Hold other oral glucose-lowering agents the morning of surgery 1
Postoperative Monitoring
Continue frequent glucose monitoring postoperatively. Basal-bolus insulin coverage (basal insulin plus premeal rapid-acting insulin) is superior to correction-only insulin for achieving better glycemic outcomes and lower complication rates in noncardiac surgery 1.
Common Pitfalls to Avoid
- Assuming stopped SGLT2 inhibitor = no monitoring needed: Wrong. The underlying diabetes still requires management during surgical stress
- Relying on CGM alone during surgery: Guidelines explicitly state this should not be done 1
- Targeting glucose <100 mg/dL: Stricter targets than 100-180 mg/dL do not improve outcomes and increase hypoglycemia risk 1
- Forgetting to check if Farxiga was actually stopped: Always verify medication reconciliation—cases of perioperative ketoacidosis have occurred when SGLT2 inhibitors were inadvertently continued 4