Sliding Scale Lispro Dosing for Hyperglycemia
Sliding scale insulin (SSI) alone should not be used as the primary management strategy for hyperglycemia in hospitalized patients—instead, use a basal-bolus or basal-plus approach with correctional (sliding scale) lispro doses added for breakthrough hyperglycemia. 1
Why SSI Alone Is Inadequate
The American Diabetes Association strongly discourages sliding scale insulin as monotherapy because it creates a reactive rather than proactive approach to glucose management 1. Evidence demonstrates that:
- SSI alone achieves target glucose control in only 38% of patients compared to 68% with basal-bolus regimens 1
- Patients remain poorly controlled 51-68% of the time when managed with SSI alone 2
- SSI results in widely variable and often ineffectual outcomes with frequent deficiencies in monitoring and documentation 2
Recommended Approach: Basal-Plus with Correctional Doses
For patients with mild-to-moderate hyperglycemia (blood glucose <200 mg/dL or 11.1 mmol/L), use basal insulin 0.1-0.25 U/kg per day plus correctional lispro doses every 4-6 hours or before meals. 3, 1
Standard Correctional Dose Scale
For patients at standard risk of hypoglycemia, use the following lispro correction doses 1:
- Blood glucose 141-180 mg/dL: 2 units
- Blood glucose 181-220 mg/dL: 4 units
- Blood glucose 221-260 mg/dL: 6 units
- Blood glucose 261-300 mg/dL: 8 units
- Blood glucose >300 mg/dL: 10 units and notify physician
Lower-Dose Scale for High-Risk Patients
For patients at higher risk of hypoglycemia (age >65 years, renal failure, poor oral intake), use a more conservative sliding scale starting with 1-2 units for lower glucose elevations. 1
Timing Considerations
Administer lispro within 15 minutes before meals or immediately after meals when used for nutritional coverage. 4
For correctional doses in hyperglycemic patients:
- In hyperglycemic states (glucose >180 mg/dL), administering lispro 15 minutes before meals improves postprandial glucose excursion compared to administration at mealtime 5
- Avoid administering lispro 30 minutes before meals as this may cause loss of glucose control 4 hours postmeal 5
Complete Insulin Regimen Framework
For Insulin-Naive Patients or Low-Dose Home Insulin Users
Start with total daily dose (TDD) of 0.3-0.5 U/kg, divided as 50% basal insulin and 50% as prandial lispro (divided three times daily before meals), plus correctional doses. 3, 1
For Patients on Higher Home Insulin Doses (≥0.6 U/kg/day)
Reduce the TDD by 20% during hospitalization to prevent hypoglycemia in patients with poor oral intake. 3
For Patients with Poor Oral Intake or NPO Status
Use basal insulin alone (0.1-0.25 U/kg per day) with correctional lispro doses every 6 hours; hold prandial doses. 1
Critical Monitoring Requirements
- Check blood glucose before meals and at bedtime (or every 6 hours if NPO) 4
- Adjust the sliding scale if glucose remains persistently elevated—do not continue the same ineffective regimen 1
- The basal-bolus approach carries a 4-6 times higher risk of hypoglycemia than SSI alone, with incidence of mild hypoglycemia at 12-30% in controlled settings 3
Common Pitfalls to Avoid
Never use SSI alone for patients with type 1 diabetes—this is dangerous and can lead to diabetic ketoacidosis. 1
Additional critical errors to avoid:
- Continuing the same sliding scale throughout hospitalization without modification despite poor control 1
- Using premixed insulin (70/30) in the hospital setting, which has unacceptably high hypoglycemia rates 3, 1
- Failing to provide basal insulin coverage, which leads to glucose variability and rebound hyperglycemia 1, 2
When SSI Alone May Be Acceptable
SSI alone may be used only in patients without diabetes or those with well-controlled type 2 diabetes (previously on oral agents alone) who develop mild hyperglycemia in the hospital. 3
Even in these cases, add basal insulin if glucose levels cannot be maintained below 180 mg/dL (10.0 mmol/L) with correctional doses alone 3.