How to manage a patient with hyperglycemia (elevated blood sugar) on the morning of surgery?

Management of Perioperative Hyperglycemia with FBS 130 mg/dl (7.2 mmol/L)

For a patient with fasting blood sugar of 130 mg/dl (7.2 mmol/L) on the morning of surgery, subcutaneous (SC) insulin with a small correction dose is the appropriate management strategy. 1

Rationale for SC Insulin Administration

A blood glucose level of 130 mg/dl represents mild hyperglycemia that falls within acceptable perioperative ranges according to current guidelines. The American Diabetes Association recommends perioperative blood glucose targets of 100-180 mg/dL (5.6-10.0 mmol/L) 1. This level of hyperglycemia does not warrant:

• Postponing the operation (unnecessary delay)
• Moving the surgery to the end of the list (not indicated for this glucose level)
• IV insulin sliding scale (reserved for more severe hyperglycemia)

Management Algorithm:

1. Administer subcutaneous (SC) insulin using a small correction dose based on the patient's blood glucose level of 130 mg/dl 1
2. Monitor blood glucose every 2-4 hours while the patient is NPO, and continue monitoring during surgery 1
3. Resume regular glucose monitoring in recovery and transition to the patient's usual diabetes management regimen postoperatively

Clinical Considerations

Risk Assessment

• Mild hyperglycemia (130 mg/dl) does not significantly increase perioperative risk enough to justify postponing surgery 1
• Hypoglycemia carries greater perioperative risks than mild hyperglycemia, so overly aggressive insulin therapy should be avoided 1
• Studies have shown that impaired fasting glucose is associated with increased perioperative cardiovascular events in patients undergoing non-cardiothoracic surgery 2, but a level of 130 mg/dl is still within acceptable perioperative ranges

Insulin Administration

• Subcutaneous insulin is preferred over IV insulin for mild hyperglycemia (130 mg/dl) 1
• 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 for hypoglycemia after insulin administration, as it requires immediate treatment if glucose falls below 70 mg/dL 1, 3
• Continue blood glucose monitoring during surgery, avoiding the use of continuous glucose monitoring (CGM) alone for intraoperative monitoring 1

Common Pitfalls to Avoid

• Overtreatment: Aggressive insulin therapy can lead to hypoglycemia, which carries greater perioperative risks than mild hyperglycemia 1, 3
• Undertreatment: Failing to address hyperglycemia can lead to increased risk of surgical site infections and other complications 4
• Inadequate monitoring: Blood glucose should be monitored every 2-4 hours while NPO and during surgery 1
• Inappropriate insulin selection: Using IV insulin when SC insulin would be sufficient 1

Remember that surgical stress can increase blood glucose levels due to counterregulatory hormone release, necessitating additional monitoring and insulin adjustment during and after surgery 1, 3.