What is the sliding scale order for Humulin R (regular insulin) in an adult patient with diabetes and no significant renal or hepatic impairment?

Sliding Scale Insulin Should Not Be Ordered as Monotherapy

Sliding scale insulin (SSI) alone should not be used for hospitalized patients with established diabetes—instead, use a basal-bolus insulin regimen with correction doses. 1, 2, 3

Why Sliding Scale Fails

• SSI treats hyperglycemia reactively after it has already occurred, leading to poor glycemic control with only 38% of patients achieving mean blood glucose <140 mg/dL compared to 68% with basal-bolus regimens 2, 3
• SSI causes rapid glucose fluctuations that worsen both hyperglycemia and hypoglycemia 2
• Multiple major guidelines (American Diabetes Association, Endocrine Society, Diabetes Canada, Australian Diabetes Society) explicitly recommend against using SSI as monotherapy 1, 2, 3

The Correct Approach: Basal-Bolus with Correction Doses

For insulin-naive patients or those on low insulin doses:

• Start with total daily dose of 0.3-0.5 units/kg 1, 2, 3
• Give 50% as basal insulin (once or twice daily) 1, 2
• Give 50% as rapid-acting insulin divided before three meals 1, 2
• Add correction doses of rapid-acting insulin for hyperglycemia 2, 3

For high-risk patients (age >65 years, renal failure, poor oral intake):

• Use lower starting dose of 0.1-0.25 units/kg/day 1, 2

For patients already on high insulin doses at home (≥0.6 units/kg/day):

• Reduce total daily dose by 20% during hospitalization to prevent hypoglycemia 1, 2

If You Must Use Humulin R Sliding Scale (Limited Acceptable Scenarios)

SSI might be acceptable only in these specific situations: 1, 2, 3

• Patients without diabetes who have mild stress hyperglycemia 1, 2
• Well-controlled diabetes (HbA1c <7%) on minimal home therapy with only mild hyperglycemia 1, 2
• Patients who are NPO with no nutritional replacement and only mild hyperglycemia 1, 2
• Patients new to steroids or tapering steroids 1

If using a simplified SSI approach (not recommended as monotherapy):

• Give 2 units of regular insulin for premeal glucose >250 mg/dL 2
• Give 4 units of regular insulin for premeal glucose >350 mg/dL 2

Critical Pitfalls to Avoid

• Never use SSI alone in patients with type 1 diabetes—this is explicitly contraindicated 1
• Never use SSI as monotherapy in patients with established insulin requirements 3
• Avoid premixed insulin (70/30) in hospitals due to unacceptably high hypoglycemia rates 1, 2
• The basal-bolus approach carries 4-6 times higher risk of hypoglycemia than SSI, but provides superior overall glycemic control 1

Target Glucose Range

• Target 140-180 mg/dL for most non-critically ill hospitalized patients 2, 3
• If correction doses are frequently required, increase the scheduled basal and prandial insulin doses rather than continuing to rely on corrections 2