Post-Discharge Management for Diabetic Patient on Metformin and Canagliflozin After Surgery
Resume metformin after 48 hours if renal function is adequate (creatinine clearance >60 mL/min), but do not restart canagliflozin until the patient is clinically stable, eating normally, and capillary ketones are <0.6 mmol/L, typically 24-48 hours post-surgery. 1, 2
Immediate Post-Discharge Medication Management
SGLT2 Inhibitor (Canagliflozin) Resumption
- Do not restart canagliflozin immediately at discharge 2
- Ensure the patient meets ALL of the following criteria before restarting: 2
- Clinically stable with no signs of infection or surgical complications
- Resumed normal oral diet (not just clear liquids)
- Capillary ketones <0.6 mmol/L confirmed by testing
- Typically wait 24-48 hours after surgery minimum
- Critical caveat: Even patients who held SGLT2 inhibitors for >72 hours preoperatively can develop postoperative ketoacidosis, so vigilance is essential 2
Metformin Resumption
- Resume metformin after 48 hours post-surgery if renal function is adequate 1
- Verify creatinine clearance is >60 mL/min before restarting metformin 1
- If clearance is 30-60 mL/min, metformin requires dose adjustment or alternative therapy 1
Glycemic Monitoring and Insulin Management
Blood Glucose Targets and Monitoring
- Target blood glucose range: 100-180 mg/dL (5.6-10.0 mmol/L) 1
- Continue monitoring blood glucose at home until stable on resumed oral medications 1
- If blood glucose remains >180 mg/dL despite resumed oral agents, short-acting insulin may be needed temporarily 1
Insulin Transition Based on HbA1c (if insulin was used perioperatively)
For patients with HbA1c <8%: 1
- Resume previous oral medications (metformin and canagliflozin) at pre-hospitalization doses after meeting criteria above
- Taper any hospital-initiated insulin rapidly as oral agents take effect
- Follow-up with primary care physician within 1-2 weeks
For patients with HbA1c 8-9%: 1
- Resume oral medications but consider continuing basal insulin (glargine) temporarily
- Schedule consultation with endocrinologist/diabetologist for therapy intensification
- Do not discharge on correction-dose insulin alone without basal coverage
For patients with HbA1c >9% or persistent hyperglycemia (>200 mg/dL or 11 mmol/L): 1
- Continue basal-bolus insulin regimen initiated in hospital
- Urgent endocrinology consultation before discharge or within days
- Consider brief hospitalization in specialized diabetes service if glycemic control not achieved
Follow-Up Schedule
Timing of Outpatient Appointments
- HbA1c <8%: Primary care physician at 1 month 1
- HbA1c 8-9%: Endocrinologist consultation within 2-4 weeks 1
- HbA1c >9%: Urgent endocrinology evaluation, potentially before discharge 1
Critical Safety Monitoring
Prevention of Diabetic Ketoacidosis
- Educate patient on ketoacidosis warning signs: nausea, vomiting, abdominal pain, confusion, rapid breathing 1, 2
- Provide ketone testing strips for home monitoring if restarting canagliflozin 2
- Emphasize that ketoacidosis can occur even with normal blood glucose levels (euglycemic DKA) with SGLT2 inhibitors 2
Hypoglycemia Prevention
- Review hypoglycemia symptoms and treatment with patient before discharge 1
- For blood glucose <70 mg/dL (3.9 mmol/L): administer 15-20g fast-acting carbohydrates orally if conscious 1
- Recheck blood glucose in 15 minutes and repeat treatment if still low 1
Special Considerations
Hydration and Nutrition
- Maintain adequate hydration during SGLT2 inhibitor discontinuation period to reduce ketoacidosis risk 2
- Ensure patient is tolerating full oral diet before restarting canagliflozin 2
- Avoid prolonged fasting periods during recovery 2
Renal Function Monitoring
- Verify renal function before restarting metformin (creatinine clearance >60 mL/min required) 1
- If clearance 30-60 mL/min, all other oral agents may resume but metformin requires caution 1