What is the guideline for an insulin sliding scale to manage hyperglycemia?

Insulin Sliding Scale Guidelines for Hospitalized Patients

Primary Recommendation

Sliding scale insulin (SSI) alone should NOT be used as the primary treatment for managing hyperglycemia in hospitalized patients with established diabetes—instead, use a scheduled basal-bolus insulin regimen. 1, 2, 3

Why Sliding Scale Insulin Alone Is Inadequate

• SSI treats hyperglycemia reactively rather than proactively, leading to rapid blood glucose fluctuations that worsen both hyperglycemia and hypoglycemia. 2
• SSI monotherapy results in clinically significant hyperglycemia and is associated with poor outcomes, including increased postoperative complications. 3, 4
• SSI regimens are often continued throughout hospitalization without modification, even when glycemic control remains inadequate. 2
• Randomized trials consistently demonstrate superior glycemic control with basal-bolus approaches compared to SSI alone—68% of patients achieved mean blood glucose <140 mg/dL with basal-bolus versus only 38% with SSI alone. 2

Limited Acceptable Uses of Sliding Scale Insulin Alone

SSI as monotherapy may be appropriate ONLY in these specific scenarios:

• Patients without pre-existing diabetes who develop mild stress hyperglycemia during hospitalization. 3, 5
• Well-controlled type 2 diabetes patients (HbA1c <7%) on diet alone or minimal oral therapy at home who develop mild hyperglycemia during admission. 3, 5
• Patients who are NPO with no nutritional replacement and only mild hyperglycemia. 2
• Patients who are new to steroids or tapering steroids with transient hyperglycemia. 2

SSI alone should NEVER be used in patients with type 1 diabetes. 3

Recommended Insulin Regimen: Basal-Bolus Approach

For Patients with Good Oral Intake

• Start with total daily insulin dose of 0.3-0.5 units/kg, divided as 50% basal insulin (once daily) and 50% prandial insulin (divided before meals). 2, 3
• Use long-acting basal insulin analogs (glargine or detemir) given once or twice daily. 3
• Use rapid-acting insulin analogs (aspart, lispro, or glulisine) for prandial coverage before meals. 3
• Add correction doses of rapid-acting insulin for hyperglycemia as needed. 3

For Patients with Poor Oral Intake or NPO Status

• Use a basal-plus regimen: 0.1-0.25 units/kg/day of basal insulin plus correction doses of rapid-acting insulin every 6 hours or before meals if eating. 2, 5

Dose Adjustments for Safety

• Use lower doses (toward 0.3 units/kg) for patients at higher risk of hypoglycemia, including older patients, those with renal failure, or those with unpredictable oral intake. 2
• Reduce total daily insulin dose by 20% during hospitalization for patients on high insulin doses at home (≥0.6 units/kg/day) to prevent hypoglycemia. 2, 5

Glycemic Targets

Initiation Threshold

• Start insulin therapy when blood glucose is persistently ≥180 mg/dL (checked on two occasions). 1

Target Ranges

• For critically ill patients: maintain blood glucose 140-180 mg/dL. 1
• For non-critically ill patients: premeal <140 mg/dL and random <180 mg/dL. 3
• More stringent goals of 110-140 mg/dL may be appropriate for selected patients (e.g., post-cardiac surgery) if achievable without significant hypoglycemia. 1

Monitoring Requirements

• For patients eating: perform point-of-care glucose monitoring before meals. 1
• For patients NPO: monitor glucose every 4-6 hours. 1
• If correction doses are frequently required, increase the scheduled insulin doses accordingly rather than continuing to rely on corrections alone. 2

Critical Safety Considerations

Hypoglycemia Risk

• Basal-bolus regimens carry a 12-30% risk of hypoglycemia in controlled settings, which is 4-6 times higher than SSI alone (RR 5.75 for blood glucose ≤70 mg/dL). 3, 5
• Every hospital must implement a standardized hypoglycemia management protocol with documentation and tracking of all episodes. 3

Avoid These Pitfalls

• Never use premixed insulin (70/30) in hospitals due to unacceptably high hypoglycemia rates. 2, 3
• Do not continue SSI regimens without modification when glycemic control remains poor—this is a common error. 2
• Avoid dextrose infusions when patients receive other nutritional support to minimize unnecessary hyperglycemia. 1

Simplified Correction Dose Scale (When Used as Supplement)

When correction insulin is needed as part of a basal-bolus regimen:

• Give 2 units of rapid-acting insulin for premeal glucose >250 mg/dL. 2
• Give 4 units of rapid-acting insulin for premeal glucose >350 mg/dL. 2

This correction scale should supplement—not replace—scheduled basal and prandial insulin. 2, 3