What is the optimal blood glucose level to maintain after Coronary Artery Bypass Grafting (CABG)?

From the Guidelines

After coronary artery bypass graft (CABG) surgery, blood sugar levels should ideally be maintained between 100-180 mg/dL (5.6-10.0 mmol/L) during the immediate post-operative period, as recommended by the most recent guidelines 1. This moderate glycemic control is recommended for all patients, regardless of whether they have pre-existing diabetes. The goal is to avoid hyperglycemia, which increases the risk of surgical site infections, delayed wound healing, and other complications, while also avoiding hypoglycemia, which can cause neurological damage. Some key points to consider in post-CABG blood sugar management include:

• Insulin therapy is typically used in the hospital setting, with regular monitoring every 1-2 hours initially, then every 4-6 hours once stable 1.
• After discharge, patients may continue with their pre-surgery diabetes medications, though adjustments might be necessary.
• Regular monitoring, medication adherence, proper nutrition, and physical activity are essential components of post-CABG blood sugar management.
• The American Heart Association and American College of Cardiology recommend maintaining blood glucose levels <180 mg/dL to reduce postoperative complications and improve survival 1.
• Long-term management after recovery should aim for fasting blood glucose levels below 130 mg/dL (7.2 mmol/L) and hemoglobin A1C levels below 7% 1.

From the Research

Optimal Blood Glucose Level after CABG

The optimal blood glucose level to maintain after Coronary Artery Bypass Grafting (CABG) is a topic of significant interest in the medical community.

• Studies have shown that maintaining serum glucose less than or equal to 180 mg/dL in patients with diabetes during CABG reduces morbidity and mortality, lowers the incidence of wound infections, reduces hospital length of stay, and enhances long-term survival 2.
• In nondiabetic patients undergoing CABG surgery, maintaining serum glucose less than 180 mg/dL has also resulted in improved perioperative outcomes 2.
• More aggressive glycemic control (80-120 mg/dL) provides no added improvement in CABG patients with less than or equal to 3 days of ICU care in the absence of ventilatory support or multiorgan failure 2.

Glycemic Control Strategies

Different strategies have been proposed for glycemic control in patients undergoing CABG:

• Adding metformin to insulin leads to better glycemic control in type 2 diabetic patients undergoing CABG surgery without causing metabolic acidosis 3.
• Insulin remains the most appropriate agent for a majority of hospitalized patients, and modern insulin analogs offer advantages over older human insulins 4.
• Optimal glycemic management in the hospital setting requires judicious treatment of hyperglycemia while avoiding hypoglycemia, with a target glucose range of 140-180 mg/dL 4, 5.
• A basal-bolus insulin regimen is ideal for hospitalized peri-operative subjects outside the ICU, while an insulin infusion protocol is best used in the ICU 6.

Target Glucose Ranges

The target glucose ranges for patients undergoing CABG are:

• Less than 180 mg/dL for patients with diabetes during CABG 2.
• Less than 140 mg/dL before meals and less than 180 mg/dL on random checks for non-critically ill patients 5.
• Between 140 and 180 mg/dL during the operative period and ICU stay 6.