Treatment of Acute Hyperglycemia in Patients on Insulin
For patients experiencing an acute episode of hyperglycemia while on insulin therapy, administer rapid-acting insulin (aspart, glulisine, or lispro) at a dose of 4 units or 10% of the basal insulin dose for blood glucose levels around 300 mg/dL, with more aggressive dosing for higher levels. 1
Initial Assessment and Management
- For patients with blood glucose levels ≥300-350 mg/dL and/or HbA1c 10-12%, especially if symptomatic or showing catabolic features, a combination of basal insulin plus mealtime insulin is the preferred regimen 2, 3
- Rapid-acting insulin analogs (lispro, aspart, glulisine) are preferred for immediate correction of hyperglycemia due to their faster onset and shorter duration of action compared to regular human insulin 1, 4
- For hospitalized patients, target blood glucose levels ≤180 mg/dL, with additional rapid-acting insulin therapy warranted for values significantly above this target 1
Dosing Guidelines for Rapid-Acting Insulin
- For acute hyperglycemia correction, administer rapid-acting insulin at an initial dose of 4 units or 10% of the basal insulin dose 1
- In hyperglycemic patients, administer rapid-acting insulin 15-30 minutes before meals for optimal postprandial glucose control 5
- Monitor blood glucose 2-4 hours after administration to assess effectiveness and watch for potential hypoglycemia 1
Ongoing Management
- After initial correction, adjust basal insulin by 2-4 units every 3-7 days until fasting blood glucose reaches target levels 2, 1
- For persistent hyperglycemia despite optimized basal insulin, add prandial insulin starting with one injection at the largest meal, increasing by 1-2 units twice weekly based on postprandial glucose readings 1
- When adding prandial insulin to a regimen with basal insulin, consider decreasing the basal insulin dose by 4 units or 10% if A1C is <8% 1
Special Considerations
- For patients with mild to moderate diabetic ketoacidosis, subcutaneous insulin lispro given every 1-2 hours has shown similar efficacy to intravenous regular insulin infusion, potentially avoiding ICU admission 6, 7
- When blood glucose levels are persistently elevated, evaluate for diabetic ketoacidosis, especially in type 1 diabetes patients 1
- Sulfonylureas are typically discontinued when more complex insulin regimens beyond basal insulin are used 2
Monitoring and Follow-up
- Continue monitoring blood glucose every 2-4 hours until stable after administering additional rapid-acting insulin 1
- Reassess the overall insulin regimen if hyperglycemia persists, considering whether basal insulin adjustments are needed 1
- Be vigilant for hypoglycemia, especially 2-4 hours after administration when insulin action peaks 1
Potential Pitfalls and Caveats
- Avoid excessive insulin administration that could lead to hypoglycemia, especially during overnight hours when hypoglycemia may go undetected 1
- Consider the risk of insulin stacking with multiple doses of rapid-acting insulin, which can increase hypoglycemia risk 1
- Without nutritional intake, rapid-acting insulin like lispro may worsen glucose variability through frequent hypoglycemic episodes as the injection dose increases 8
- For patients on continuous enteral feeds with moderate to high insulin resistance, lispro insulin may cause rebound hyperglycemia that increases glucose variability 8