Target Pre-Operative and Post-Operative Glucose Levels for Diabetic Patients

The target blood glucose range for diabetic patients in the perioperative period should be 100-180 mg/dL (5.6-10.0 mmol/L). 1

Pre-Operative Glucose Management

The A1C target for elective surgeries should be <8% (63.9 mmol/L) whenever possible to reduce surgical risk 1
Blood glucose should be maintained between 100-180 mg/dL (5.6-10.0 mmol/L) within 4 hours of surgery 1
Stricter glycemic targets (<100 mg/dL) are not recommended as they increase the risk of hypoglycemia without improving outcomes 1
Preoperative medication management:
- Metformin should be held on the day of surgery 1
- SGLT2 inhibitors must be discontinued 3-4 days before surgery 1
- Hold all other oral glucose-lowering agents the morning of surgery 1
- Give half of NPH dose or 75-80% of long-acting insulin analog dose based on clinical judgment 1

Maintain blood glucose between 100-180 mg/dL (5.6-10.0 mmol/L) during surgery 1
For cardiac surgery patients, intraoperative insulin infusion should be started and maintained with a goal of blood glucose <180 mg/dL 1
Continuous intravenous insulin is the preferred method for critically ill patients requiring insulin during surgery 1, 2
Subcutaneous insulin may be appropriate for non-critically ill patients 3
Monitor blood glucose at least every 2-4 hours during surgery 1

Continue to target blood glucose between 100-180 mg/dL (5.6-10.0 mmol/L) in the post-operative period 1
For cardiac surgery patients, maintain insulin infusion into the early post-operative period with a goal of <180 mg/dL 1
Poor intraoperative glycemic control (persistent glucose >200 mg/dL) is associated with increased post-operative morbidity 4
In non-cardiac surgery patients, basal-bolus insulin regimens (basal insulin plus premeal short/rapid-acting insulin) have shown better outcomes than correction-only insulin regimens 1
Monitor blood glucose at least every 2-4 hours while the patient is NPO and administer short or rapid-acting insulin as needed 1

Evidence from a recent study indicates that reducing the evening pre-surgery insulin dose by 25% improves the likelihood of achieving target perioperative glucose levels with lower hypoglycemia risk 1
For patients with stress hyperglycemia (transient glucose elevation >150 mg/dL during acute illness), similar glucose targets apply 1
Perioperative glycemic targets tighter than 80-180 mg/dL have not shown improved outcomes and are associated with increased hypoglycemia risk 1
Continuous glucose monitoring (CGM) should not be used alone for glucose monitoring during surgery 1

Attempting to achieve overly tight glucose control (<140 mg/dL) increases hypoglycemia risk without clear benefit 1, 2
Failing to monitor glucose levels frequently enough during the perioperative period 5
Using correction-only insulin without basal insulin coverage in non-cardiac surgery patients 1
Not adjusting insulin doses based on anticipated changes in steroid dosing and other factors affecting glucose levels 1
Delaying insulin therapy when blood glucose exceeds target range, particularly in cardiac surgery patients 4