What is the sliding scale protocol for managing blood glucose levels in diabetic patients?

Sliding Scale Insulin Protocol for Diabetic Patients

Sliding scale insulin alone is strongly discouraged for managing diabetes in hospitalized patients as it is ineffective and should be replaced with basal-bolus insulin regimens. 1, 2

Recommended Insulin Management Approach

Basal-Bolus Insulin Regimen (Preferred Approach)

1. Initial Dosing:

   • Calculate total daily insulin dose at 0.3-0.5 units/kg/day for insulin-naive patients 2
   • Divide into 50% basal insulin and 50% prandial insulin 2
   • Use lower doses (0.3 units/kg/day) for patients at higher risk of hypoglycemia (elderly, renal impairment, poor oral intake) 2

2. Basal Insulin:

   • Administer long-acting insulin (glargine or detemir) once or twice daily 2
   • Adjust dose based on fasting glucose values 2
   • Increase dose by 2 units if 50% of fasting glucose readings remain above 150 mg/dL after one week 2
   • Decrease dose by 2 units if any fasting glucose readings fall below 80 mg/dL 2

3. Bolus (Prandial) Insulin:

   • Administer rapid-acting insulin immediately before meals 2
   • Add correction doses for hyperglycemia based on individualized sensitivity factors 2

Correction Dose Protocol

For blood glucose values above target, add rapid-acting insulin as follows:

• 250 mg/dL: Add 2 units

• 350 mg/dL: Add 4 units 2

Monitoring Protocol

Hospitalized Patients

• For patients who are eating: Monitor glucose before meals 2
• For patients not eating: Monitor every 4-6 hours 2
• For patients on continuous NG feeding: Monitor every 4-6 hours 2
• For patients on intermittent NG feeding: Monitor before meals and at bedtime 2
• For patients on IV insulin: Monitor every 30 minutes to 2 hours 2

Target Blood Glucose Range

• General hospitalized patients: 140-180 mg/dL 2
• Older adults: 90-150 mg/dL (less aggressive targets) 2

Hypoglycemia Management Protocol

1. Define hypoglycemia as blood glucose <70 mg/dL 2
2. For mild-moderate hypoglycemia (54-70 mg/dL) in conscious patients:
   • Administer 15-20g oral carbohydrate
   • Recheck blood glucose after 15 minutes 2
3. For severe hypoglycemia (<54 mg/dL) or unconscious patients:
   • Administer IV dextrose 25g (50 mL of 50% solution) or
   • Glucagon 1mg IM/SC if IV access is not available 2

Special Considerations

Transitioning from IV to Subcutaneous Insulin

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

Renal Impairment

• Reduce insulin doses by 20-25% 2

Pre-Surgery Management

• Consider reducing evening insulin dose by 25% before surgery 2

Why Sliding Scale Alone Is Discouraged

Sliding scale insulin as monotherapy is strongly discouraged because:

1. It is reactive rather than preventive (dosing given in response to elevated glucose) 1
2. It does not account for basal insulin requirements 1
3. It results in poor glycemic control with persistent hyperglycemia 3
4. Randomized controlled trials have shown that basal-bolus treatment improves glycemic control and reduces hospital complications compared to sliding scale insulin regimens 1

The American Diabetes Association, American College of Clinical Endocrinologists, and other major guidelines consistently recommend against using sliding scale insulin alone for managing diabetes in hospitalized patients 1, 2.