How to manage a patient with a fasting blood sugar (FBS) level of 130 mg/dl on the morning of surgery?

Management of a Patient with Fasting Blood Sugar of 130 mg/dl on the Day of Surgery

For a patient with a fasting blood sugar of 130 mg/dl (7.2 mmol/L) on the morning of surgery, subcutaneous insulin should be administered using a correction dose based on the patient's blood glucose level, with continued monitoring throughout the perioperative period.

Assessment of the Blood Glucose Level

A fasting blood sugar of 130 mg/dl (7.2 mmol/L) represents mild hyperglycemia that falls within acceptable perioperative ranges according to current guidelines. This level does not warrant postponing surgery as it does not significantly increase perioperative risk 1.

• The American Diabetes Association recommends perioperative blood glucose targets of 100-180 mg/dL (5.6-10.0 mmol/L) 2, 1
• A target blood sugar level of < 180 mg/dL (10 mmol/L) helps avoid hypoglycemia while preventing excessive hyperglycemia 2
• The target range for blood glucose in the perioperative period should be 100–180 mg/dL (5.6–10.0 mmol/L) within 4 hours of surgery 2

Management Approach

Recommended Option: Subcutaneous Insulin (Option B)

• For mild hyperglycemia (130 mg/dl), a small correction dose of rapid-acting insulin is appropriate 1
• Subcutaneous insulin is preferred over IV insulin for mild hyperglycemia (130 mg/dl) because IV insulin infusion is typically reserved for:
  • Severe hyperglycemia (>200 mg/dl)
  • Patients with type 1 diabetes undergoing major surgery
  • Critically ill patients 1

Monitoring Protocol

• Monitor blood glucose every 2-4 hours while the patient is NPO 2, 1
• Continue blood glucose monitoring during surgery 1
• Resume regular glucose monitoring in recovery 1
• Watch for hypoglycemia after insulin administration, as it requires immediate treatment if glucose falls below 70 mg/dL 1

Why Other Options Are Not Recommended

Option A: Postponing the Operation

• Not recommended as a blood glucose level of 130 mg/dl falls within acceptable perioperative ranges 1
• Postponing surgery for mild hyperglycemia does not improve outcomes and may unnecessarily delay needed treatment 1

Option C: Do Surgery at the End of the List

• Not supported by evidence-based guidelines
• Actually contradicts recommendations to schedule diabetic patients early in the day to avoid prolonged fasting 2

Option D: IV Insulin, Sliding Scale

• IV insulin infusion is typically reserved for severe hyperglycemia (>200 mg/dl) 1
• For mild hyperglycemia (130 mg/dl), subcutaneous insulin is more appropriate 1
• IV insulin protocols are complex and difficult to execute without computer programs 2
• Aggressive insulin therapy increases risk of hypoglycemia, which carries greater perioperative risks than mild hyperglycemia 1

Important Considerations

• Surgical stress can increase blood glucose levels due to counterregulatory hormone release, necessitating additional monitoring during and after surgery 1
• Hypoglycemia carries greater perioperative risks than mild hyperglycemia 1
• Impaired fasting glucose (100-125 mg/dl) and diabetes are associated with increased perioperative cardiovascular events, with every 10 mg/dl increase in preoperative plasma glucose related to an 11% increase in adverse events 3
• Basal-bolus insulin regimens have been associated with improved glycemic outcomes compared with correction-only insulin coverage 2

In conclusion, for a patient with a fasting blood sugar of 130 mg/dl on the morning of surgery, the most appropriate management is to administer subcutaneous insulin using a correction dose and continue with the scheduled surgery while maintaining appropriate monitoring throughout the perioperative period.