What's the anesthetic plan for a diabetic patient on dapagliflozin and sitagliptin undergoing radical hemicolectomy?

Anesthetic Management for a Diabetic Patient on Dapagliflozin and Sitagliptin Undergoing Radical Hemicolectomy

The optimal anesthetic plan for this 49-year-old diabetic patient on dapagliflozin and sitagliptin undergoing radical hemicolectomy should include discontinuation of dapagliflozin 3-4 days preoperatively, implementation of intravenous insulin therapy during the perioperative period, and either general anesthesia with a volatile-based agent or combined general-epidural anesthesia with careful glycemic monitoring.

Preoperative Assessment and Medication Management

Diabetes Medication Management

• Dapagliflozin (SGLT2 inhibitor):

  • Must be discontinued 3-4 days before surgery to prevent euglycemic diabetic ketoacidosis, a serious complication defined as normoglycemia with metabolic acidosis 1
  • Should not be restarted until the patient is clinically stable and has resumed a normal diet 1

• Sitagliptin (DPP-4 inhibitor):

  • Hold on the morning of surgery 2
  • Can be safely resumed once oral intake is established postoperatively

Preoperative Evaluation

• Check HbA1c if not obtained within the past 3 months 1
• Target blood glucose range: 5-10 mmol/L (90-180 mg/dL) 1, 2
• Consider postponing elective surgery if blood glucose >16.5 mmol/L (300 mg/dL) 1
• Assess for diabetes-related complications:
  • Cardiac autonomic neuropathy (orthostatic hypotension, heart rate variability) 1
  • Difficult airway risk (evaluate using palm print test due to glycosylation of collagen in temporomandibular joints) 1
  • Gastroparesis (risk of aspiration) 2

Intraoperative Management

Anesthetic Technique

• Either general anesthesia or combined general-epidural anesthesia is appropriate 1
  • No evidence suggests any specific anesthetic agent provides better outcomes in diabetic patients 1
  • For general anesthesia, either volatile-based anesthesia or total intravenous anesthesia can be used with no difference in cardiovascular outcomes 1
  • If using epidural, a mid-thoracic epidural with local anesthetics and low-dose opioids is recommended for open colonic surgery 1

Glycemic Management

• Implement intravenous insulin therapy protocol:
  • Use ultra-rapid insulin diluted to 1 IU/mL concentration 1
  • Provide simultaneous glucose infusion (D10% at 40 mL/h) unless hyperglycemia is present 1
  • Target blood glucose: 5-10 mmol/L (90-180 mg/dL) 1, 2
  • Monitor blood glucose hourly during surgery, and after any change in insulin infusion rate 1
  • Administer insulin bolus if blood glucose >10 mmol/L (180 mg/dL) 1

Enhanced Recovery Considerations

• Follow ERAS protocol principles for colonic surgery 1:
  • Avoid routine nasogastric intubation
  • Maintain normothermia with appropriate warming devices
  • Consider multimodal PONV prophylaxis (note: limit dexamethasone to 4 mg due to hyperglycemia risk) 1

Postoperative Management

Pain Management

• Effective pain control is essential as poorly controlled pain can worsen hyperglycemia 1
• If epidural is used, continue for postoperative analgesia
• Consider multimodal analgesia with standard analgesics (no dose modifications needed for diabetes) 1
• Note that patients with poor glycemic control (higher HbA1c) may have higher analgesic requirements 1

Glycemic Control

• Continue frequent blood glucose monitoring
• Transition from IV insulin to subcutaneous insulin once oral intake is established
• Resume sitagliptin once eating normally
• Do not restart dapagliflozin until patient is clinically stable with normal oral intake, typically several days after surgery 1
• Monitor for signs of euglycemic diabetic ketoacidosis (metabolic acidosis with normal or slightly elevated blood glucose)

Common Pitfalls and Caveats

1. Failure to discontinue SGLT2 inhibitors (dapagliflozin) adequately before surgery can lead to euglycemic diabetic ketoacidosis, a serious complication that may be difficult to recognize due to relatively normal blood glucose levels 1

2. Underestimating airway difficulty in long-standing diabetic patients due to glycosylation of collagen in temporomandibular joints 1

3. Overlooking autonomic neuropathy which can cause unexpected hemodynamic instability during anesthesia 2

4. Inadequate PONV prophylaxis - particularly important for diabetic patients to ensure early resumption of oral intake 1

5. Using high-dose dexamethasone (8 mg) for PONV prophylaxis can significantly worsen hyperglycemia; limit to 4 mg and combine with another antiemetic agent 1