What is the sliding scale insulin regimen for managing hyperglycemia?

Sliding Scale Insulin for Hyperglycemia

Sliding scale insulin (SSI) alone should generally NOT be used as the primary treatment for hospitalized patients with diabetes, except in very limited circumstances such as patients without pre-existing diabetes who have mild stress hyperglycemia, or patients with well-controlled type 2 diabetes (HbA1c <7%) managed by diet alone at home who develop mild hyperglycemia during hospitalization. 1

When SSI Alone May Be Acceptable

SSI as monotherapy is appropriate only for:

• Patients without diabetes who develop mild stress hyperglycemia during hospitalization 1
• Well-controlled type 2 diabetes patients (HbA1c <7%) on diet alone or minimal oral therapy at home who have mild hyperglycemia 1, 2
• Patients who are NPO with no nutritional replacement and only mild hyperglycemia 1, 2
• Patients new to steroids or tapering steroids 1, 2

SSI should NEVER be used alone in patients with type 1 diabetes as this is dangerous and can lead to diabetic ketoacidosis. 1, 3

Why SSI Alone Is Discouraged

The evidence against SSI as monotherapy is compelling:

• Poor glycemic control: SSI treats hyperglycemia reactively rather than proactively, leading to mean blood glucose levels that are 14.8 mg/dL (0.8 mmol/L) higher compared to basal-bolus regimens 4
• Lower success rates: Only 38% of patients on SSI alone achieve target glucose control versus 68% with basal-bolus insulin 3, 2
• Increased hyperglycemic events: Meta-analysis shows SSI is associated with significantly more hyperglycemic episodes 5
• Glucose variability: SSI creates rapid blood glucose fluctuations that worsen both hyper- and hypoglycemia 2

Recommended Alternative: Basal-Plus Approach

For most hospitalized patients requiring insulin, a basal-plus regimen is superior to SSI alone. 1

Basal-Plus Dosing Algorithm:

• Basal insulin: 0.1-0.25 units/kg/day given once daily 1, 3
• Plus correction doses of rapid-acting insulin before meals or every 6 hours if NPO 1

This approach is particularly appropriate for:

• Patients with mild hyperglycemia (blood glucose <200 mg/dL) 1
• Patients with decreased oral intake 1
• Patients undergoing surgery 1

Sample SSI Correction Scale (When Appropriate)

When SSI is used as a correction component (not as monotherapy), a simplified approach includes:

• Blood glucose >250 mg/dL: Give 2 units of rapid-acting insulin 2
• Blood glucose >350 mg/dL: Give 4 units of rapid-acting insulin 2

Lower-dose scales should be used for high-risk patients (>65 years, renal failure, poor oral intake), starting with 1-2 units for lower glucose elevations. 3

When to Escalate from SSI

If a patient on SSI alone cannot maintain blood glucose <180 mg/dL, add basal insulin immediately. 1, 6

The target should be:

• 140-180 mg/dL for most hospitalized patients 3, 2

Safety Considerations

While basal-bolus regimens provide better glycemic control, they carry 4-6 times higher risk of hypoglycemia compared to SSI alone (RR 5.75 for blood glucose ≤70 mg/dL). 1 However, the incidence of severe hypoglycemia remains low in controlled settings at 12-30%. 1

For patients on high-dose insulin at home (≥0.6 units/kg/day), reduce total daily dose by 20% during hospitalization to prevent hypoglycemia. 1, 2

Common Pitfalls to Avoid

• Never continue the same SSI regimen throughout hospitalization without modification despite poor control 3, 2
• Avoid premixed insulin (70/30) in the hospital due to unacceptably high hypoglycemia rates 1, 3
• Do not automatically place all diabetic patients on basal-bolus regardless of their outpatient regimen, as this can cause unnecessary hypoglycemia in well-controlled patients 6