What are the strategies for controlling postoperative hyperglycemia?

From the Guidelines

Post-operative hyperglycemia should be managed with a target blood glucose range of 100-180 mg/dL (5.6-10.0 mmol/L) for most surgical patients, using basal-bolus insulin therapy with a reduction of 25% of basal insulin given the evening before surgery to achieve perioperative blood glucose goals with a lower risk for hypoglycemia 1.

Strategies for Controlling Postoperative Hyperglycemia

The management of postoperative hyperglycemia is crucial to prevent adverse outcomes, including deep sternal wound infection and other complications. The following strategies can be employed:

• Initial management typically involves basal-bolus insulin therapy, with a starting regimen of 0.2-0.5 units/kg/day of total insulin, divided as 50% basal (glargine or detemir once daily) and 50% as prandial insulin (regular insulin or rapid-acting analogs like lispro, aspart, or glulisine) 1.
• Blood glucose monitoring should occur before meals and at bedtime, with additional checks if symptoms of hypoglycemia develop.
• For patients who cannot eat, continuous intravenous insulin infusion may be necessary, starting at 0.5-1 units/hour and titrated based on hourly glucose measurements.
• Correction doses should be added for glucose values above target.
• Hypoglycemia risk increases with aggressive control, so protocols should include treatment plans for glucose levels below 70 mg/dL.

Importance of Glycemic Control

Post-operative hyperglycemia requires attention because surgical stress triggers insulin resistance and increased hepatic glucose production through stress hormone release (cortisol, catecholamines, glucagon), which can impair wound healing and increase infection risk 1. As the patient recovers, insulin requirements typically decrease, necessitating dose adjustments before discharge.

Recommendations

The American Diabetes Association recommends that the A1C goal for elective surgeries should be <8% (<63.9 mmol/L) whenever possible, and the blood glucose goal in the perioperative period should be 100–180 mg/dL (5.6–10.0 mmol/L) within 4 h of the surgery 1. Stricter perioperative glycemic goals are not advised, as they may not improve outcomes and are associated with increased hypoglycemia 1.

From the FDA Drug Label

Medication Insulin requirements may be increased if you are taking other drugs with blood-glucose-raising activity, such as oral contraceptives, corticosteroids, or thyroid replacement therapy Hyperglycemia (too much glucose in the blood) may develop if your body has too little insulin Hyperglycemia can be brought about by any of the following: Omitting your insulin or taking less than your doctor has prescribed. Eating significantly more than your meal plan suggests. Developing a fever, infection, or other significant stressful situation.

The strategies for controlling postoperative hyperglycemia include:

• Administering insulin as prescribed by a doctor
• Avoiding omitting insulin or taking less than prescribed
• Following a meal plan to avoid eating significantly more than suggested
• Managing stressful situations such as fever or infection
• Adjusting insulin regimen to accommodate changes in the body's need for insulin, such as during exercise or travel across time zones 2

From the Research

Strategies for Controlling Postoperative Hyperglycemia

• The use of once-daily insulin glargine has been shown to provide good glycemic control in hyperglycemic patients after cardiovascular surgery 3
• Constant-rate intravenous insulin therapy is effective in lowering arterial whole blood glucose concentrations in postoperative coronary artery bypass graft patients 4
• Insulin glargine has been found to provide better glycemic control after an abdominal surgical procedure than the traditional use of sliding scale regular insulin (SSRI) 5
• Intraoperative blood glucose management has been associated with postoperative blood glucose levels, with adequate management by initiating insulin infusion when glucose level exceeds 140 mg/dL to prevent hyperglycemia being associated with lower postoperative glucose levels and fewer incidences of postoperative hyperglycemia 6
• Basal/bolus insulin regimens are safer and more effective in hospitalized patients than supplemental-scale regular insulin for optimal glycemic control 7

Insulin Therapies

• Twice-daily NPH/regular insulin has been found to provide better control than glargine insulin monotherapy, but with a higher incidence of hypoglycemia 3
• Constant insulin infusions at a rate of eight units or 20 units/hr have been used to control hyperglycemia in postoperative coronary artery bypass graft patients 4
• Once-daily insulin glargine has been compared to 6-hour sliding scale regular insulin for control of hyperglycemia after a bariatric surgical procedure, with glargine providing better control 5

Glycemic Targets

• The glycemic target in the perioperative period needs to be clearly communicated to implement proper insulin replacement for optimal glycemic control 7
• Target blood glucose levels have varied across studies, including 80-140 mg/dL 3, 151-250 mg/dL 4, and 144 mg/dL 5
• Intraoperative hyperglycemia (>180 mg/dL) has been associated with postoperative hyperglycemia, and initiating insulin for a hyperglycemia threshold of 180 mg/dL was associated with an increase in postoperative glucose level and postoperative hyperglycemia incidence 6