Moderate Dose Sliding Scale Insulin Protocol
Direct Answer
Sliding scale insulin (SSI) alone should not be used as a primary insulin regimen in hospitalized patients with established diabetes, as it is ineffective, reactive rather than proactive, and leads to worse glycemic control compared to scheduled basal-bolus or basal-plus regimens. 1, 2
Why Sliding Scale Insulin Fails
Traditional sliding scale insulin regimens have fundamental flaws that make them inappropriate for most hospitalized patients:
- Reactive approach: SSI treats hyperglycemia after it has already occurred instead of preventing it, leading to rapid blood glucose fluctuations that worsen both hyper- and hypoglycemia 1
- Poor glycemic control: Meta-analysis shows SSI provides no benefit in blood glucose control but increases hyperglycemic events (mean blood glucose 27.33 mg/dL higher than non-SSI regimens) 3
- Static dosing: SSI regimens prescribed on admission typically remain unchanged throughout hospitalization even when control remains poor 1
- Inferior outcomes: Only 38% of patients on SSI alone achieve mean blood glucose <140 mg/dL compared to 68% with basal-bolus insulin 1
When SSI May Be Acceptable (Limited Scenarios)
Sliding scale insulin as monotherapy is appropriate only in these specific situations:
- Mild stress hyperglycemia in patients without pre-existing diabetes 1, 2
- Well-controlled diabetes (HbA1c <7%) on minimal home therapy with only mild hyperglycemia during hospitalization 2
- NPO patients with no nutritional replacement and only mild hyperglycemia 2
- Steroid-related hyperglycemia in patients new to steroids or tapering steroids 2
Recommended Alternative: Basal-Plus Approach
For patients requiring insulin therapy, use a basal-plus regimen instead:
Initial Dosing
- Total daily dose: 0.1-0.25 units/kg/day for patients at higher hypoglycemia risk (elderly, renal failure, poor oral intake) 1, 2, 4
- Standard dose: 0.3-0.5 units/kg/day for insulin-naive patients or those on low insulin doses 1
- Dose reduction: Decrease total daily dose by 20% for patients on high home insulin doses (≥0.6 units/kg/day) to prevent hypoglycemia 1, 2
Distribution
- 50% as basal insulin: Given once or twice daily (long-acting analog or NPH) 1
- 50% as correction doses: Rapid-acting insulin before meals or every 4-6 hours if NPO 1, 5
Simplified Correction Dose Scale (When SSI Component Is Used)
If using correction doses as part of a basal-plus regimen:
- Premeal glucose >250 mg/dL: Give 2 units of rapid-acting insulin 2
- Premeal glucose >350 mg/dL: Give 4 units of rapid-acting insulin 2
- Adjust scheduled doses: If correction doses are frequently required, increase the basal insulin dose accordingly 1, 2
Critical Pitfalls to Avoid
- Never use SSI as monotherapy in patients with type 1 diabetes—this can lead to diabetic ketoacidosis 5, 2
- Avoid premixed insulin (70/30) in hospitals due to unacceptably high hypoglycemia rates 1, 2
- Do not continue ineffective SSI: If SSI is initially prescribed and proves inadequate, transition immediately to scheduled basal insulin 1
- Monitor for hypoglycemia: Basal-bolus approaches carry 4-6 times higher hypoglycemia risk than SSI, requiring vigilant monitoring 1, 4
Target Glucose Range
- Conventional target: 140-180 mg/dL for most hospitalized patients 2
- Avoid tight control: Targeting euglycemia (80-110 mg/dL) substantially increases hypoglycemia risk and is discouraged 1
Monitoring and Adjustment
- Frequency: Check blood glucose every 4-6 hours for subcutaneous regimens 5, 6
- Dose titration: Increase basal insulin by 2 units every 3 days to reach fasting glucose goal without hypoglycemia 1
- Hypoglycemia response: If hypoglycemia occurs without clear cause, reduce corresponding insulin dose by 10-20% 1