Can a patient with hyperglycemia but no diabetic ketoacidosis (DKA) be managed with a sliding scale insulin regimen?

Can Sliding Scale Insulin Be Used for Hyperglycemia Without Ketoacidosis?

Sliding scale insulin (SSI) alone should generally not be used for hospitalized patients with hyperglycemia, even in the absence of ketoacidosis, except in very specific circumstances: patients without pre-existing diabetes who have mild stress hyperglycemia, or patients with well-controlled type 2 diabetes (HbA1c <7%) managed by diet alone at home who develop mild hyperglycemia during hospitalization. 1, 2, 3

Why SSI Alone Is Discouraged

The American Diabetes Association strongly discourages the sole use of SSI in the inpatient hospital setting because it treats hyperglycemia reactively rather than proactively. 1, 2 This reactive approach leads to:

• Rapid blood glucose fluctuations that exacerbate both hyperglycemia and hypoglycemia 2
• Clinically significant hyperglycemia with poorer glycemic control compared to scheduled insulin regimens 2
• SSI regimens often continue throughout hospital stays without modification, even when control remains poor 2

Randomized trials consistently demonstrate that basal-bolus insulin regimens achieve superior glycemic control compared to SSI alone in patients with type 2 diabetes. 1 The basal-bolus approach resulted in:

• Mean blood glucose control <140 mg/dL in 68% of patients versus only 38% with SSI alone 2
• Reduction in complications including postoperative wound infection, pneumonia, bacteremia, and acute renal and respiratory failure 1, 2

When SSI Alone May Be Acceptable

SSI as monotherapy is appropriate only in these limited scenarios:

• Patients without pre-existing diabetes who develop mild stress hyperglycemia during hospitalization 2, 3
• Well-controlled type 2 diabetes patients (HbA1c <7%) on diet alone or minimal oral therapy at home who have mild hyperglycemia 3, 4
• Patients who are NPO with no nutritional replacement and only mild hyperglycemia 3
• Patients who are new to steroids or tapering steroids 2

Recommended Approach Instead of SSI Alone

For Most Hospitalized Patients with Diabetes

A basal-plus or basal-bolus insulin regimen is the preferred treatment approach. 1, 2

For patients with good oral intake:

• Start with a basal-bolus regimen: 0.3-0.5 units/kg total daily dose 1, 2
• Divide 50% as basal insulin (given once or twice daily) and 50% as rapid-acting insulin (divided before three meals) 1, 2
• Add correction doses of rapid-acting insulin for hyperglycemia 1

For patients with poor oral intake or NPO:

• Use a basal-plus approach: 0.1-0.25 units/kg/day of basal insulin 1, 2, 3
• Add correction doses of rapid-acting insulin before meals or every 6 hours if NPO 1, 3

For Diet-Controlled Type 2 Diabetes Patients

For patients who manage their diabetes with diet alone at home, SSI alone may be the initial approach. 4 These patients typically have adequate beta-cell function and do not require scheduled basal insulin initially. 4

• Monitor blood glucose before meals and at bedtime (or every 4-6 hours if NPO) 4
• Add basal insulin only if blood glucose levels consistently remain above 180 mg/dL despite correctional insulin 4
• If basal insulin becomes necessary, start with a low dose of 0.1-0.25 units/kg/day 4

Important Safety Considerations

Hypoglycemia Risk

The basal-bolus approach carries a 4-6 times higher risk of hypoglycemia compared to SSI alone (RR 5.75 for blood glucose ≤70 mg/dL). 1, 3, 4 In controlled settings, the incidence of mild hypoglycemia with basal-bolus insulin is 12-30%. 1, 2

Dose Adjustments to Prevent Hypoglycemia

• Use lower doses (0.3 units/kg or less) for patients at higher risk: older patients (>65 years), those with renal failure, and those with poor oral intake 1, 2
• For patients on high-dose insulin at home (≥0.6 units/kg/day), reduce the total daily insulin dose by 20% during hospitalization to prevent hypoglycemia 1, 2, 3

What to Avoid

• Never use premixed insulin (70/30) in the hospital as it has been associated with unacceptably high rates of hypoglycemia 1, 2, 3
• Do not automatically place all diabetic patients on basal-bolus insulin regardless of their outpatient regimen, as this can lead to unnecessary hypoglycemia 4
• SSI should never be used as the sole treatment for patients with type 1 diabetes 1

Glycemic Targets

For non-critically ill hospitalized patients:

• Premeal blood glucose targets <140 mg/dL (7.8 mmol/L) 1
• Random blood glucose <180 mg/dL (10.0 mmol/L) 1
• These targets should be achieved safely without significant hypoglycemia 1

Monitoring and Adjustment

• If correction doses are frequently required, increase the scheduled insulin doses accordingly 2
• Monitor for hypoglycemia and have a hypoglycemia management protocol in place 1
• Document and track all episodes of hypoglycemia in the medical record 1