Fast Insulin Sliding Scale Protocol for Hospitalized Patients with Hyperglycemia
The use of a correction or supplemental insulin (sliding scale) without basal insulin in the inpatient setting is strongly discouraged, as it leads to suboptimal glycemic control and increased rates of hyperglycemia. 1
Recommended Insulin Protocol
Basal-Bolus-Correction Approach
A basal-bolus insulin regimen with correctional insulin is the preferred treatment for most non-critically ill hospitalized patients with hyperglycemia who have adequate nutritional intake 1, 2.
Step 1: Calculate Total Daily Insulin Dose
- Calculate 0.3-0.5 units/kg/day for total daily dose (TDD) 2
- For example: 70 kg patient = 21-35 units total daily insulin
Step 2: Distribute Insulin Components
- Basal insulin: 50% of TDD as long-acting insulin (glargine or detemir) once or twice daily 2
- Prandial insulin: 50% of TDD divided into three doses before meals 2
- Correction insulin: Added based on pre-meal glucose readings using standardized scales
Step 3: Implement Correction Scale Based on Insulin Sensitivity
For correction/sliding scale component, use one of these standardized scales 2:
| Blood Glucose (mg/dL) | Low-Dose Scale | Moderate-Dose Scale | High-Dose Scale |
|---|---|---|---|
| 140-180 | 1 unit | 2 units | 3 units |
| 181-220 | 2 units | 4 units | 6 units |
| 221-260 | 3 units | 6 units | 9 units |
| 261-300 | 4 units | 8 units | 12 units |
| 301-350 | 5 units | 10 units | 15 units |
| 351-400 | 6 units | 12 units | 18 units |
| >400 | 7 units | 14 units | 21 units |
- Low-dose: Insulin sensitive, elderly, renal impairment
- Moderate-dose: Most hospitalized patients
- High-dose: Insulin resistant, obese, on steroids
Special Considerations
For Patients with Poor Oral Intake
- Reduce total insulin dose to 0.1-0.15 units/kg/day, primarily as basal insulin 2
- For variable intake, administer rapid-acting insulin after meals based on actual consumption 2
For Patients on Enteral/Parenteral Nutrition
Follow specific protocols based on feeding type 1:
| Feeding Type | Basal/Nutritional Insulin | Correctional Insulin |
|---|---|---|
| Continuous enteral | Continue prior basal or start with 5 units NPH/detemir q12h or 10 units glargine/degludec daily. Add regular insulin q6h or rapid-acting q4h (1 unit per 10-15g carbs) | Regular insulin q6h or rapid-acting q4h |
| Bolus enteral | Continue prior basal or start with 5 units NPH/detemir q12h or 10 units glargine/degludec daily. Add regular or rapid-acting insulin before each feeding (1 unit per 10-15g carbs) | Regular insulin q6h or rapid-acting q4h |
| Parenteral | Add regular insulin to TPN solution (1 unit per 10g carbs) | Regular insulin q6h or rapid-acting q4h |
Blood Glucose Monitoring
- For patients eating meals: Check before meals and at bedtime 2
- For patients NPO or on continuous feeding: Check every 4-6 hours 2
- For patients on IV insulin: Check every 30 minutes to 2 hours until stable 2
Target Blood Glucose Range
- Target blood glucose range: 140-180 mg/dL for most hospitalized patients 2
- Avoid tight glycemic control (<140 mg/dL) as it increases risk of hypoglycemia without improving outcomes 1
Hypoglycemia Management
Implement a hypoglycemia protocol for all patients 1, 2:
- Define hypoglycemia as blood glucose <70 mg/dL
- For mild-moderate hypoglycemia (54-70 mg/dL) in conscious patients: Administer 15-20g oral carbohydrate
- For severe hypoglycemia (<54 mg/dL) or unconscious patients: Administer IV dextrose or glucagon
- Review and adjust insulin regimen after any hypoglycemic episode
Common Pitfalls to Avoid
- Using sliding scale insulin alone: This approach is associated with a 3-fold higher risk of hyperglycemic episodes compared to no pharmacologic regimen 3
- Not adjusting for special populations: African American patients and those with low albumin have higher hypoglycemia risk 3
- Failing to reduce insulin for interrupted feeding: If enteral feeding is interrupted, start 10% dextrose at 50 mL/hr to prevent hypoglycemia 2
- Not adjusting insulin before procedures: Consider reducing evening insulin dose by 25% before surgery 1
Transition to Discharge
- Resume home regimen 1-2 days before discharge 2
- Schedule follow-up within 1-4 weeks of discharge 2
- Provide structured discharge education on insulin administration
By implementing this comprehensive basal-bolus-correction approach rather than relying solely on sliding scale insulin, hospitals can achieve better glycemic control and reduce complications in patients with hyperglycemia.