What is the perioperative management for a patient on Metformin (biguanide) and Teneligliptin (dipeptidyl peptidase-4 inhibitor) undergoing vaginal hysterectomy?

Perioperative Management of Metformin and Teneligliptin for Vaginal Hysterectomy

Stop metformin the night before surgery and hold teneligliptin on the morning of surgery; restart metformin only after 48 hours postoperatively with confirmed adequate renal function (eGFR ≥60 mL/min/1.73m²), and resume teneligliptin when the patient is eating normally. 1, 2, 3

Preoperative Management

Metformin

• Discontinue metformin the evening before surgery (12-24 hours preoperatively) 1, 2, 3
• While recent evidence suggests metformin may not be as strongly associated with lactic acidosis as previously feared, the conservative approach of perioperative discontinuation remains standard practice across all major guidelines 1, 2
• The plasma half-life of metformin is 6.2 hours, so stopping the night before allows for significant drug clearance 2
• Check baseline renal function (eGFR) before surgery, as renal impairment is the primary risk factor for metformin-associated lactic acidosis (MALA), which carries 30-50% mortality 2, 4, 5

Teneligliptin (DPP-4 Inhibitor)

• Hold teneligliptin on the morning of surgery 1
• DPP-4 inhibitors like teneligliptin are generally safer perioperatively than other oral agents, but should still be held on the day of surgery 1
• No specific extended preoperative discontinuation period is required for DPP-4 inhibitors, unlike SGLT2 inhibitors which require 3-4 days 1, 3

Additional Preoperative Considerations

• Target HbA1c <8% for elective surgery when possible 1, 3
• Perform preoperative cardiovascular risk assessment if the patient has high-risk cardiac disease, autonomic neuropathy, or renal failure 1
• Ensure adequate hydration status before surgery 4

Intraoperative Management

Glycemic Control

• Target blood glucose range: 100-180 mg/dL during the perioperative period 1, 3
• Tighter glycemic targets are not advised as they increase hypoglycemia risk without improving outcomes 1
• Monitor blood glucose every 2-4 hours while NPO 1, 3

Insulin Management

• Use basal-bolus insulin regimen (basal insulin plus short/rapid-acting insulin for corrections) rather than sliding scale alone, as this improves outcomes and reduces complications 1, 2, 3
• If the patient was on basal insulin preoperatively, give 75-80% of the usual long-acting analog dose or 50% of NPH dose on the morning of surgery 1, 3
• Administer short- or rapid-acting insulin as needed based on blood glucose monitoring 1

Anesthetic Considerations

• Either general or neuraxial anesthesia is reasonable for vaginal hysterectomy with no apparent difference in cardiovascular events 1
• Administer IV antibiotic prophylaxis within 60 minutes before incision 1
• Maintain euvolemia and avoid extremes of fluid balance 1

Postoperative Management

Immediate Postoperative Period

• Continue monitoring blood glucose every 2-4 hours 1, 3
• Maintain target glucose 100-180 mg/dL 1, 3
• Continue basal-bolus insulin regimen until patient resumes normal oral intake 1, 3
• Use multimodal, opioid-sparing analgesia 1

Restarting Metformin

Critical timing and criteria:

• Wait 48 hours after surgery before restarting metformin 1, 2, 3, 4
• Confirm eGFR ≥60 mL/min/1.73m² before restarting 2, 4, 5
• Ensure patient is eating and drinking normally 2, 4
• Verify no ongoing hemodynamic instability (no vasopressor requirement, no acute heart failure, no sepsis, no respiratory insufficiency) 2, 4

Do NOT restart metformin at 48 hours if:

• Dehydration persists 2, 4
• Ongoing vasopressor requirement 2, 4
• Acute heart failure 2, 4
• Sepsis 2, 4
• Respiratory insufficiency 2, 4
• eGFR <60 mL/min/1.73m² 2, 4, 5

Restarting Teneligliptin

• Resume teneligliptin when patient is eating normally and tolerating oral intake 1
• Can typically be restarted earlier than metformin (once eating well) as it does not carry the lactic acidosis risk 1
• Continue at the same preoperative dose 1

Common Pitfalls to Avoid

• Do not restart metformin before 48 hours, even if renal function appears normal, as surgery can cause transient renal impairment that may not be immediately apparent 2, 4
• Do not use sliding scale insulin alone—basal-bolus regimens are superior and reduce complications 1, 2, 3
• Do not allow blood glucose to exceed 180 mg/dL or drop below 100 mg/dL perioperatively 1, 3
• Do not confuse DPP-4 inhibitors with SGLT2 inhibitors—SGLT2 inhibitors require 3-4 days preoperative discontinuation due to euglycemic DKA risk, while DPP-4 inhibitors only need to be held the morning of surgery 1, 3

Special Considerations for Vaginal Hysterectomy

• Vaginal hysterectomy is well-tolerated even in medically compromised patients with diabetes, with minimal perioperative morbidity 6
• Early catheter removal reduces postoperative pain 1
• Enhanced recovery protocols emphasize early mobilization and oral intake, which facilitates earlier resumption of oral diabetes medications 1