What is the difference between correctional insulin every 4 hours as needed and a sliding scale insulin regimen for glucose control?

Correctional Insulin vs. Sliding Scale Insulin: Key Differences

Correctional insulin and sliding scale insulin are fundamentally different approaches to managing hyperglycemia, with correctional insulin being a component of a comprehensive insulin regimen while sliding scale insulin is a reactive approach that should be avoided as the sole therapy for inpatient glycemic management. 1

Key Differences

Correctional Insulin:

• Definition: Supplemental insulin given to "correct" high blood glucose readings
• Administration: Given every 4 hours (for rapid-acting insulin) or every 6 hours (for regular insulin) 1
• Role: Used as part of a comprehensive insulin regimen that includes:
  • Basal insulin (long-acting)
  • Prandial insulin (meal-time)
  • Correctional insulin (for unexpected hyperglycemia)
• Approach: Proactive and preventive when used with basal-bolus regimen

Sliding Scale Insulin (SSI):

• Definition: A reactive insulin regimen where insulin doses are determined solely based on current blood glucose readings
• Administration: Typically given every 4-6 hours based on blood glucose readings
• Role: Often used as the sole therapy for hyperglycemia management
• Approach: Reactive - treats hyperglycemia after it occurs rather than preventing it 2

Evidence Against Sliding Scale Insulin

Multiple guidelines strongly discourage the use of sliding scale insulin as the sole therapy for inpatient glycemic management:

• The American Diabetes Association (ADA) explicitly recommends against prolonged use of sliding scale insulin regimens 1
• A randomized controlled trial showed that basal-bolus treatment improved glycemic control and reduced hospital complications compared with sliding scale insulin regimens 1
• Studies have shown that sliding scale insulin alone leads to:
  • Poor glycemic control 3, 4
  • Higher rates of hyperglycemic episodes 4
  • Increased medication errors 5
  • Rapid blood glucose fluctuations 2

Recommended Approach

For hospitalized patients requiring insulin therapy, guidelines recommend:

1. Basal-bolus insulin regimen that includes:

   • Basal insulin (50-70% of total daily dose)
   • Prandial insulin (before meals)
   • Correctional insulin (to address unexpected hyperglycemia) 1, 2

2. For patients who are NPO (not eating):

   • Basal insulin plus correctional insulin 1, 2

3. For patients who are eating:

   • Basal insulin + prandial insulin + correctional insulin 1

Common Pitfalls to Avoid

1. Using sliding scale insulin as the sole therapy - This reactive approach leads to poor glycemic control and increased complications 1, 4

2. Not adjusting insulin regimens - Studies show that sliding scale insulin regimens are rarely adjusted despite persistent hyperglycemia 3

3. Poor documentation and monitoring - Up to 30% of sliding scale insulin administrations have documentation or timing issues 3

4. Failing to transition to appropriate regimens - Many patients remain on sliding scale insulin throughout hospitalization despite poor control 2, 3

In summary, correctional insulin is a component of a comprehensive insulin regimen used to address unexpected hyperglycemia, while sliding scale insulin is a reactive approach that should not be used as the sole therapy for glycemic management in hospitalized patients.