What is the sliding scale approach for managing blood glucose levels with short-acting insulin, such as aspart (NovoLog) or lispro (Humalog), in patients with hyperglycemia?

Sliding Scale Approach for Short-Acting Insulin Management

The traditional sliding scale insulin (SSI) regimen alone is strongly discouraged for managing hyperglycemia in hospitalized patients as it is ineffective, reactive rather than preventive, and associated with poor glycemic control. 1

Preferred Insulin Regimens for Hyperglycemia Management

Basal-Bolus Approach (Recommended)

• For patients with established diabetes and good nutritional intake:
  • Total daily insulin dose: 0.3-0.5 units/kg/day 1
  • Distribution: 50% as basal insulin, 50% as prandial insulin 1
  • Lower doses (0.3 units/kg/day) for patients at higher risk of hypoglycemia:
    • Elderly patients (>65 years)
    • Renal failure
    • Poor oral intake 1
  • For patients on higher home insulin doses (≥0.6 units/kg/day), reduce total daily dose by 20% to prevent hypoglycemia 1

Basal-Plus-Correction Approach

• For patients with mild hyperglycemia, decreased oral intake, or those undergoing surgery:
  • Single dose of basal insulin (0.1-0.25 units/kg/day) 1
  • Add correction doses of rapid-acting insulin for elevated glucose levels 1
  • Administer correction doses before meals or every 6 hours if NPO 1

Correction Insulin (Supplemental to Scheduled Insulin)

• Use rapid-acting insulin analogs (aspart, lispro) or regular insulin
• Administer immediately before meals for patients eating regularly 1
• For poor oral intake, administer immediately after meals based on amount consumed 1

Implementation of Short-Acting Insulin Therapy

Timing of Administration

• Rapid-acting analogs (aspart/NovoLog, lispro/Humalog):
  • Peak activity: 2.3-2.4 hours after dosing 2
  • 70% of activity occurs in first 4 hours 2
  • Administer within 15 minutes before meals 2
• Regular human insulin:
  • Peak activity: 4.4 hours after dosing 2
  • 54% of activity occurs in first 4 hours 2
  • Administer 30-60 minutes before meals 2

Blood Glucose Monitoring

• For patients eating: Test immediately before meals 1
• For NPO patients: Test every 4-6 hours 1
• Adjust frequency based on clinical stability and treatment regimen

Common Pitfalls and How to Avoid Them

1. Using SSI as monotherapy

   • Problem: Associated with persistent hyperglycemia and poor outcomes 3, 4
   • Solution: Always combine with basal insulin for patients with established diabetes 1

2. Failure to adjust insulin regimens

   • Problem: Studies show sliding scale regimens are rarely adjusted despite poor control 3
   • Solution: Regularly evaluate glycemic control and adjust insulin doses accordingly

3. Hypoglycemia risk

   • Problem: Basal-bolus regimens have higher hypoglycemia risk (12-30% incidence of mild hypoglycemia) 1
   • Solution: Implement hypoglycemia prevention protocols and reduce doses for high-risk patients 1

4. Inappropriate use of premixed insulin

   • Problem: Associated with unacceptably high rates of hypoglycemia 1
   • Solution: Avoid premixed insulin formulations in hospitalized patients

5. Relying solely on correction insulin

   • Problem: Treats hyperglycemia after it occurs rather than preventing it 1
   • Solution: Use proactive scheduled insulin regimens with basal component 1

Special Considerations

Patients with Type 1 Diabetes

• SSI alone should never be used in patients with type 1 diabetes 1
• Always maintain basal insulin to prevent diabetic ketoacidosis

Patients with Mild Stress Hyperglycemia

• SSI alone may be appropriate for patients without diabetes who have mild stress hyperglycemia 1
• Consider adding basal insulin if unable to maintain glucose <180 mg/dL 1

Transitioning from IV to Subcutaneous Insulin

• Administer subcutaneous basal insulin 2-4 hours before discontinuing IV insulin 1
• Convert to 60-80% of daily IV insulin infusion dose as basal insulin 1

By implementing these evidence-based approaches instead of traditional sliding scale insulin monotherapy, you can achieve better glycemic control and reduce complications in hospitalized patients with hyperglycemia.