What is the recommended insulin dosing regimen for a patient with hyperglycemia?

Insulin Dosing for Hyperglycemia

Recommended Insulin Regimen Based on Severity

For hospitalized patients with hyperglycemia, insulin is the preferred treatment, with the specific regimen determined by clinical setting and severity of hyperglycemia. 1

Critically Ill Patients (ICU Setting)

• Intravenous insulin infusion is the preferred route for all critically ill patients with hyperglycemia, targeting blood glucose 140-180 mg/dL, with upper limit not exceeding 180 mg/dL 1
• Avoid targeting blood glucose <110 mg/dL due to increased hypoglycemia risk without mortality benefit 1
• Use insulin infusion protocols with demonstrated safety and efficacy that result in low rates of hypoglycemia 1

Non-Critically Ill Hospitalized Patients

The insulin regimen should be stratified by severity of hyperglycemia and prior insulin use: 1

Mild Hyperglycemia (Blood Glucose <200 mg/dL)

• Consider low-dose basal insulin (0.1-0.2 units/kg/day) or oral antidiabetic agents if patient is insulin-naive or on <2 antidiabetic agents at home 1
• Add correction doses with rapid-acting insulin before meals or every 6 hours as needed 1

Moderate Hyperglycemia (Blood Glucose 201-300 mg/dL)

• Start basal insulin at 0.2-0.3 units/kg/day for patients on multiple antidiabetic agents at home or with total daily insulin dose <0.6 units/kg/day 1
• Provide correction doses with rapid-acting insulin before meals or every 6 hours 1

Severe Hyperglycemia (Blood Glucose >300 mg/dL)

• Implement basal-bolus insulin regimen immediately 1
• If patient was on insulin at home: reduce home total daily dose by 20%, giving half as basal insulin and half as prandial insulin divided before meals 1
• If insulin-naive: start at 0.3 units/kg/day total daily dose, with 50% as basal and 50% as prandial (divided before meals) 1
• For patients on home insulin >0.6 units/kg/day, continue similar total daily dose with basal-bolus split 1

Special Populations

Type 1 Diabetes

• Continuous insulin infusion is preferred in the ICU setting 1
• Never discontinue basal insulin completely, even if patient is NPO 1
• Patients using insulin pumps at home may continue self-management if mentally and physically capable 1

Glucocorticoid-Induced Hyperglycemia

• Start multiple-dose insulin at 1-1.2 units/kg/day, distributed as 25% basal and 75% prandial for patients receiving high-dose steroids with blood glucose >250 mg/dL on two occasions 1
• For patients without diabetes on steroids, consider single morning dose of NPH insulin (0.1-0.3 units/kg/day) 1
• Add NPH insulin to existing regimen for patients with diabetes already on insulin, with dose determined by steroid dose and oral intake 1

Transitioning from IV to Subcutaneous Insulin

• Transition to protocol-driven basal-bolus subcutaneous insulin regimen before stopping IV insulin to prevent rebound hyperglycemia 1
• Delay subcutaneous insulin initiation until: no planned interruptions of nutrition, peripheral edema resolved, and patient off vasopressors 1
• Administer first subcutaneous dose 2-4 hours before discontinuing IV insulin infusion 1

Insulin Adjustment Protocols

Basal Insulin Titration

• Increase basal insulin by 2-4 units every 3-7 days until fasting blood glucose reaches target of 80-130 mg/dL 1, 2
• Reduce dose if blood glucose falls below 70 mg/dL 1
• Reassess regimen if blood glucose falls below 100 mg/dL 1

Adding Prandial Insulin

• Initiate prandial insulin when fasting glucose is at target but HbA1c remains elevated, or when significant postprandial excursions occur (>180 mg/dL) 1, 2
• Start with 4 units or 10% of basal insulin dose before the largest meal 2
• Increase by 1-2 units or 10-15% twice weekly based on postprandial glucose readings 2
• Consider decreasing basal insulin by 4 units or 10% when adding prandial insulin if HbA1c <8% 2

Critical Pitfalls to Avoid

• Never use sliding-scale insulin (correction insulin only) as the sole method of insulin treatment in hospitalized patients—this approach is strongly discouraged and ineffective 1, 2
• Avoid premeal glucose targets <100 mg/dL to prevent hypoglycemia 1
• Do not continue sulfonylureas when implementing complex insulin regimens beyond basal insulin, as this significantly increases hypoglycemia risk 1, 2
• Prevent insulin stacking by accounting for insulin-on-board when giving correction doses 1
• Ensure proper timing: administer subcutaneous basal insulin before discontinuing IV insulin to avoid hyperglycemic rebound 1

Nutritional Considerations

• Evaluate amount and timing of carbohydrate intake when calculating insulin requirements 1
• For patients on enteral nutrition: use basal insulin (NPH every 8 hours, detemir every 12 hours, or glargine every 24 hours) plus short-acting insulin every 4-6 hours 1
• If tube feeding is interrupted, start IV 10% dextrose at 50 mL/hour to prevent hypoglycemia 1
• Provide 200-300 grams of dextrose per day for patients on parenteral nutrition receiving insulin infusion 1

Monitoring Requirements

• Monitor blood glucose every 2-4 hours during IV insulin infusion until stable, then continue monitoring to maintain target range 1
• For subcutaneous insulin regimens, monitor blood glucose before meals and at bedtime (minimum 4 times daily) 1
• Increase monitoring frequency with any insulin dose changes, changes in clinical status, or nutritional interruptions 1