What is the protocol for administering sliding scale insulin (SSI) therapy?

Sliding Scale Insulin Protocol

Sliding scale insulin (SSI) alone should not be used as the primary method of glucose control in hospitalized patients with diabetes, as it is reactive rather than preventive and leads to poor glycemic control and increased complications. 1

Proper Approach to Insulin Therapy in Hospital Setting

Basal-Bolus Approach (Preferred Method)

For most hospitalized patients with diabetes, a basal-bolus insulin regimen is recommended:

1. Calculate total daily insulin dose:

   • For insulin-naive patients: 0.3-0.5 units/kg/day 1
   • For patients already on insulin: Reduce home dose by 20% to prevent hypoglycemia 1
   • Lower doses for elderly patients (>65 years), those with renal failure, or poor oral intake 1

2. Distribute insulin components:

   • 50% as basal insulin (once or twice daily)
   • 50% as prandial insulin (divided into three doses before meals) 1

3. Add correction insulin (supplemental) to scheduled insulin doses:

   • Measure blood glucose before meals and at bedtime
   • Administer short or rapid-acting insulin based on pre-meal glucose values 1

When to Use Simplified Sliding Scale

While SSI alone is discouraged, a simplified sliding scale may be appropriate in specific situations:

• Patients without diabetes who have mild stress hyperglycemia 1
• As a temporary supplement to scheduled insulin during dose adjustment 1
• During transition periods while establishing basal-bolus regimen 1

Example of Simplified Sliding Scale (as supplemental insulin only)

• For premeal glucose >250 mg/dL (>13.9 mmol/L): Give 2 units of short/rapid-acting insulin
• For premeal glucose >350 mg/dL (>19.4 mmol/L): Give 4 units of short/rapid-acting insulin 1

Special Considerations

NPO (Nothing by Mouth) Patients

• Use basal-plus-correction insulin regimen 1
• Continue basal insulin at 60-80% of usual dose
• Add correction insulin every 4-6 hours 1

Older Adults

• Consider simplification of insulin regimens
• Higher target glucose ranges (90-150 mg/dL fasting) 1
• Reduce insulin doses to prevent hypoglycemia

Type 1 Diabetes

• SSI alone should NEVER be used in patients with type 1 diabetes 1
• Always maintain basal insulin even when NPO

Monitoring and Adjustment

1. Frequent glucose monitoring:

   • Before meals and at bedtime for patients who are eating
   • Every 4-6 hours for NPO patients 1

2. Insulin dose adjustment:

   • If correction doses are frequently required, increase scheduled insulin doses 1
   • If >2 readings/week are <80 mg/dL, decrease basal insulin by 2 units 1
   • If 50% of readings are above target, increase basal insulin by 2 units 1

Common Pitfalls to Avoid

1. Using SSI as monotherapy: This reactive approach leads to poor glycemic control, with studies showing only 38% of patients achieving target glucose compared to 68% with basal-bolus regimens 1

2. Not adjusting the sliding scale: Many hospitals continue the same sliding scale throughout hospitalization without modification despite poor control 1

3. Ignoring hypoglycemia risk factors: Hospital-related factors that increase hypoglycemia risk include:

   • Sudden reduction of corticosteroid doses
   • Altered ability to report symptoms
   • Reduced oral intake or unexpected interruption of feeding
   • Inappropriate timing of insulin relative to meals 1

4. Failing to transition properly: When discontinuing IV insulin, give subcutaneous insulin 1-2 hours before stopping the infusion, converting to 60-80% of the daily infusion dose as basal insulin 1

By implementing a standardized protocol for insulin administration with proper basal-bolus coverage rather than relying solely on sliding scale insulin, hospitals can significantly reduce medication errors and adverse glycemic events 2.