What is the recommended approach for a sliding scale (sliding scale insulin regimen) insulin regimen in patients with hyperglycemia?

Sliding Scale Insulin Should Not Be Used as Monotherapy for Hospitalized Patients with Diabetes

Sliding scale insulin (SSI) alone is an outdated, reactive approach that should be replaced with scheduled basal-bolus insulin regimens for hospitalized patients with diabetes, as SSI monotherapy leads to inferior glycemic control, increased complications, and dangerous blood glucose fluctuations. 1, 2

Why Sliding Scale Insulin Fails

Sliding scale insulin treats hyperglycemia only after it occurs, creating a reactive cycle that perpetuates poor control rather than preventing it 1, 2. This approach leads to:

• Clinically significant hyperglycemia with only 38% of patients achieving mean blood glucose <140 mg/dL compared to 68% with basal-bolus regimens 2
• Rapid blood glucose fluctuations that exacerbate both hyper- and hypoglycemia 1
• Increased hospital complications including postoperative wound infections and acute renal failure 1, 2
• Persistent poor control as SSI regimens are often continued throughout hospitalization without modification 1

The Recommended Approach: Scheduled Basal-Bolus Insulin

For Patients with Good Oral Intake

Start with a basal-bolus regimen using a total daily dose of 0.3-0.5 units/kg/day, divided 50% as basal insulin (once daily) and 50% as prandial insulin (before meals). 1, 2

• For insulin-naive patients or those on low home doses, this weight-based approach provides both basal coverage and meal-time insulin 1, 2
• Add correction doses of rapid-acting insulin for hyperglycemia as needed 1, 2
• For patients already on high home insulin doses (≥0.6 units/kg/day), reduce the total daily dose by 20% during hospitalization to prevent hypoglycemia 1, 2

For Patients with Poor or No Oral Intake

Use a basal-plus approach with 0.1-0.25 units/kg/day of basal insulin plus correction doses of rapid-acting insulin for hyperglycemia. 1, 2

• This prevents the dangerous glucose fluctuations that occur when prandial insulin is given to NPO patients 2
• Adjust based on glucose patterns and nutritional intake 1

Limited Acceptable Uses of Sliding Scale Insulin

SSI might be appropriate only in highly specific situations 1:

• Mild stress hyperglycemia in patients without pre-existing diabetes
• Well-controlled diabetes (HbA1c <7%) on minimal home therapy with only mild hyperglycemia during hospitalization
• NPO patients with no nutritional replacement and only mild hyperglycemia
• Steroid-related hyperglycemia in patients new to steroids or tapering doses

Even in these situations, SSI should be used as an adjunct to scheduled insulin, not as monotherapy 1, 2.

Critical Safety Considerations

Hypoglycemia Risk

The basal-bolus approach carries a 4-6 times higher hypoglycemia risk than SSI alone, with a risk ratio of 5.75 (95% CI 2.79-11.83) for blood glucose ≤70 mg/dL 2. To mitigate this:

• Implement hospital-wide hypoglycemia protocols for glucose <70 mg/dL 2
• Review the treatment regimen after any glucose <70 mg/dL 2
• Use basal-plus rather than full basal-bolus for fasting patients or those undergoing procedures 2
• For high-risk patients (elderly >65 years, renal failure, poor oral intake), use lower doses of 0.1-0.25 units/kg/day 3, 1

Special Populations

For older adults, consider simplified regimens such as once-daily basal insulin with simplified sliding scale only as an adjunct 2.

For patients with type 1 diabetes, SSI alone should never be used as it is associated with clinically significant hyperglycemia and increased complications 1.

Transitioning from IV to Subcutaneous Insulin

When discontinuing IV insulin infusion 2:

• Administer subcutaneous basal insulin 2-4 hours before stopping IV infusion
• Convert at 60-80% of daily IV infusion dose
• Add prandial insulin as appropriate based on nutritional intake

Common Pitfalls to Avoid

• Never use premixed insulin (70/30) in hospitals due to unacceptably high hypoglycemia rates 1, 2
• Do not continue SSI monotherapy when control remains poor—this perpetuates the problem rather than solving it 1
• Avoid treating all hyperglycemia reactively—scheduled insulin prevents hyperglycemia rather than chasing it 1, 2
• Do not forget to reduce home insulin doses by 20% in patients on high doses (≥0.6 units/kg/day) during hospitalization 1, 2