Insulin Sliding Scale for Hospitalized Patients
Correction-only sliding scale insulin (SSI) should NOT be used as the sole therapy for hospitalized patients with diabetes, but may be appropriate for patients without diabetes who have mild stress hyperglycemia or those with well-controlled diabetes experiencing only occasional hyperglycemia. 1, 2
When Sliding Scale Insulin Alone IS Appropriate
The most recent 2021 Lancet guidelines specifically recommend sliding scale insulin alone for 1:
- Patients WITHOUT diabetes who have mild stress hyperglycemia
- Patients with good metabolic control on oral antidiabetic drugs at home
- Add basal insulin if glucose cannot be maintained below 180 mg/dL (10.0 mmol/L)
Why SSI Alone Is Discouraged for Diabetic Patients
The evidence against correction-only SSI is compelling:
- Poor glycemic control: SSI is associated with clinically significant hyperglycemia and provides no benefit in blood glucose control 1, 3
- Increased hyperglycemic events: When used alone, SSI carries a 3-fold higher risk of hyperglycemic episodes compared to no pharmacologic treatment 4
- Reactive rather than proactive: SSI treats hyperglycemia after it has already occurred, rather than preventing it 1
- 14% failure rate: In randomized trials, 14% of patients on SSI alone required rescue therapy with basal-bolus insulin due to persistent glucose >240 mg/dL 2
Recommended Correction Insulin Dosing Scale
When correction insulin IS used (as part of a scheduled regimen, not alone), the 2012 Endocrine Society guideline provides specific dosing 2:
For patients eating regular meals:
| Blood Glucose (mg/dL) | Insulin-Sensitive | Usual | Insulin-Resistant |
|---|---|---|---|
| 141-180 | 2 units | 4 units | 6 units |
| 181-220 | 4 units | 6 units | 8 units |
| 221-260 | 6 units | 8 units | 10 units |
| 261-300 | 8 units | 10 units | 12 units |
| 301-350 | 10 units | 12 units | 14 units |
| 351-400 | 12 units | 14 units | 16 units |
For NPO patients:
- Use rapid-acting insulin every 4-6 hours OR regular insulin every 6 hours
- Follow the "sensitive" column 2
What Should Be Used Instead
For patients with diabetes requiring insulin 1, 2, 5:
Basal-Plus Regimen (preferred for most):
- Single dose of basal insulin: 0.1-0.25 units/kg/day
- PLUS correction doses before meals or every 6 hours if NPO
- Lower risk of hypoglycemia than full basal-bolus
- Appropriate for mild hyperglycemia (<200 mg/dL), decreased oral intake, or surgical patients
Full Basal-Bolus Regimen (for significant hyperglycemia):
- Total daily dose: 0.3-0.5 units/kg (0.2-0.3 units/kg for elderly >65 years, renal impairment, or poor intake)
- 50% as basal insulin (once or twice daily)
- 50% as prandial insulin (divided before three meals)
- PLUS correction doses
Critical Exceptions
Never use SSI alone in:
- Type 1 diabetes patients - they require continuous basal insulin to prevent DKA, even when NPO 1, 2
- Type 2 diabetes patients with significant hyperglycemia - basal insulin is mandatory 1
Key Safety Consideration
While basal-bolus regimens provide superior glycemic control, they carry a 4-6 times higher risk of hypoglycemia compared to SSI alone 1. This is why the basal-plus approach represents a middle ground for appropriate patients, balancing efficacy with safety.
The 2025 ADA Standards specifically state: "Prolonged use of correction or supplemental insulin without basal insulin is strongly discouraged in the inpatient setting, with the exception of people with type 2 diabetes in noncritical care with mild hyperglycemia or stress hyperglycemia." 6