What is the protocol for managing an insulin sliding scale?

Insulin Sliding Scale Management Protocol

The basal-bolus insulin approach is strongly recommended over sliding scale insulin (SSI) alone for managing hyperglycemia in hospitalized patients, as SSI alone is ineffective and associated with poor glycemic control and increased complications. 1, 2

Appropriate Insulin Regimens

Basal-Bolus Insulin Regimen (Preferred Approach)

• For insulin-naive patients or those on low doses, use a total daily insulin dose of 0.3-0.5 units/kg 2
  • 50% as basal insulin (once or twice daily)
  • 50% as rapid-acting insulin divided before meals
  • Plus correction doses for hyperglycemia
• For patients already on higher insulin doses (≥0.6 units/kg/day), reduce total daily dose by 20% during hospitalization to prevent hypoglycemia 2
• Target glucose range: 90-150 mg/dL (5.0-8.3 mmol/L) before meals 2

Basal-Plus Approach (Alternative for Selected Patients)

• Preferred for patients with mild hyperglycemia, decreased oral intake, or those undergoing surgery 2
• Single dose of basal insulin (0.1-0.25 units/kg/day) plus correction doses of rapid-acting insulin 2
• Simpler than full basal-bolus but more effective than SSI alone 2

When Using Correction Insulin (Simplified Sliding Scale)

• For premeal glucose >250 mg/dL (>13.9 mmol/L): give 2 units of short or rapid-acting insulin 2
• For premeal glucose >350 mg/dL (>19.4 mmol/L): give 4 units of short or rapid-acting insulin 2
• Adjust doses based on patient characteristics (lower doses for elderly, renal impairment) 1

Monitoring and Adjustment Protocol

Basal Insulin Titration

• Check fasting glucose values over a week 2
• If 50% of fasting values exceed target: increase basal dose by 2 units 2
• If >2 fasting values/week are <80 mg/dL: decrease basal dose by 2 units 2

Prandial Insulin Adjustment

• Monitor pre-lunch and pre-dinner glucose levels every 2 weeks 2
• If 50% of premeal values over 2 weeks exceed target: increase dose or add another agent 2
• If >2 premeal values/week are <90 mg/dL: decrease medication dose 2

Special Considerations

Transitioning from IV to Subcutaneous Insulin

• Ensure patient is stable with normal glucose measurements for at least 4-6 hours 2
• Calculate subcutaneous insulin requirements based on average insulin infused during previous 12 hours 2
• Example: If average IV rate was 1.5 units/hour, estimated daily dose would be 36 units/24 hours 2

Common Pitfalls to Avoid

• Using SSI alone for patients with type 1 diabetes is dangerous and should never be done 1
• Continuing the same sliding scale regimen throughout hospitalization without modification despite poor control 1, 3
• Using premixed insulin therapy (70/30) in hospital settings due to high hypoglycemia risk 1
• Failing to adjust insulin doses when transitioning between care settings 1

Evidence on Effectiveness

• Randomized trials consistently show better glycemic control with basal-bolus approach than with SSI alone 2, 1
• Basal-bolus regimens achieve target glucose control in 68% of patients versus only 38% with SSI alone 1
• Studies show SSI alone is associated with a 3-fold higher risk of hyperglycemic episodes compared to other regimens 4
• The incidence of mild iatrogenic hypoglycemia with basal-bolus approach is about 12-30% in controlled settings 2

By implementing a structured insulin protocol that incorporates basal insulin with meal-time and correction doses rather than relying solely on sliding scale insulin, you can achieve better glycemic control and reduce complications in hospitalized patients with diabetes.