Sliding Scale Insulin Control Recommendations
For patients requiring sliding scale insulin control, a basal-bolus insulin regimen is strongly recommended over sliding scale insulin alone as the initial approach due to superior glycemic control and reduced complications. 1
Limitations of Sliding Scale Insulin Alone
- Sliding scale insulin (SSI) alone is widely used in hospitals despite being condemned in clinical guidelines due to its association with clinically significant hyperglycemia 1
- SSI treats hyperglycemia reactively (after it occurs) rather than preventively, leading to rapid blood glucose fluctuations that exacerbate both hyper- and hypoglycemia 1
- SSI regimens prescribed on admission are often used throughout hospital stays without modification, even when control remains poor 1
- SSI alone should never be used in patients with type 1 diabetes 1
Recommended Initial Approach
Basal-Bolus Regimen
- For insulin-naive patients or those on low insulin doses, start with a total daily insulin dose of 0.3-0.5 units/kg 1
- Allocate half of the total daily insulin dose to basal insulin (given once or twice daily) and half to rapid-acting insulin (divided three times daily before meals) 1
- Lower doses should be used for patients at higher risk of hypoglycemia (older patients >65 years, those with renal failure, or poor oral intake) 1
- For patients already on higher insulin doses (≥0.6 units/kg/day), reduce the total daily insulin dose by 20% during hospitalization to prevent hypoglycemia 1
Basal-Plus Approach
- For patients with mild hyperglycemia, decreased oral intake, or those undergoing surgery, consider a basal-plus approach 1
- This consists of a single dose of basal insulin (0.1-0.25 units/kg/day) along with correctional doses of insulin for elevated glucose levels 1
Evidence Supporting Recommendations
- Randomized trials consistently show better glycemic control with basal-bolus approaches compared to sliding scale insulin alone in patients with type 2 diabetes 1, 2
- The basal-bolus approach is associated with reduced complications including postoperative wound infection, pneumonia, bacteremia, and acute renal and respiratory failure 1
- In one study, glycemic control (defined as mean blood glucose <140 mg/dl) was achieved in 68% of patients receiving basal-bolus insulin versus only 38% of those receiving sliding scale insulin alone 1
- A multicenter trial showed that a target blood glucose of <140 mg/dl was achieved in 66% of patients in the basal-bolus group compared to only 38% in the SSI group 2
Special Considerations
- For patients with mild stress hyperglycemia without diabetes, sliding scale insulin might be appropriate 1
- For patients transitioning from IV insulin infusion to subcutaneous insulin, calculate the daily dose based on the average insulin infused during the previous 12 hours 1
- When using a simplified sliding scale during adjustment of prandial insulin, consider:
- Stop sliding scale when not needed daily 1
Monitoring and Adjustment
- Use fasting plasma glucose values to titrate basal insulin 3
- Use both fasting and postprandial glucose values to titrate mealtime insulin 3
- If correction doses are frequently required, increase the scheduled insulin doses accordingly 1
- Target a conventional glucose range of 140-180 mg/dL for most hospitalized patients 1
Cautions and Pitfalls
- Basal-bolus approach may lead to hypoglycemia in 12-30% of patients in controlled settings 1
- Avoid premixed insulin therapy in the hospital as it has been associated with unacceptably high rates of hypoglycemia 1
- Never abruptly discontinue oral medications when starting insulin therapy due to risk of rebound hyperglycemia 3
- Use the shortest needles available (4-mm pen and 6-mm syringe needles) to avoid intramuscular injections that could cause severe hypoglycemia 3
By implementing these evidence-based recommendations for sliding scale insulin control, clinicians can achieve better glycemic control and reduce complications in hospitalized patients requiring insulin therapy.