For an adult hospitalized patient with type 2 diabetes, irregular meals, no severe renal or hepatic impairment, no frequent hypoglycemia, and not on basal insulin, should regular insulin be administered subcutaneously using a sliding scale of 150–200 mg/dL → 2 U, 200–250 mg/dL → 4 U, 250–300 mg/dL → 6 U, and 300–350 mg/dL → 8 U?

Sliding Scale Insulin Alone Should Not Be Used for This Patient

For a hospitalized adult with type 2 diabetes and irregular meals who is not on basal insulin, sliding scale regular insulin alone is strongly discouraged and should be replaced with a basal-plus or basal-bolus insulin regimen. 1

Why Sliding Scale Insulin Alone Fails

The proposed sliding scale approach is fundamentally flawed because it:

• Treats hyperglycemia reactively after it has already occurred rather than preventing it, leading to wide glycemic fluctuations 1
• Results in clinically significant hyperglycemia in the majority of patients with established type 2 diabetes 1
• Has been condemned in clinical guidelines despite persistent widespread use 1
• Shows inferior glycemic control compared to basal-bolus regimens in randomized trials 1
• Increases complications including postoperative wound infections, pneumonia, bacteremia, and acute renal/respiratory failure when compared to scheduled insulin regimens 1

The Superior Alternative: Basal-Plus Approach

For this patient with irregular meals and no current basal insulin, implement a basal-plus regimen consisting of:

Initial Dosing Strategy

• Start basal insulin at 0.1–0.25 units/kg/day given once daily (glargine or detemir preferred over NPH) 1
• Add correction doses of rapid-acting insulin (aspart, lispro, or glulisine) before meals or every 6 hours if NPO 1
• For a 70 kg patient, this translates to approximately 7–18 units of basal insulin daily as a starting point 1

Correction Dose Scale (Not Sliding Scale Monotherapy)

The correction insulin should supplement—not replace—basal insulin:

• 150–200 mg/dL: 2 units rapid-acting insulin
• 200–250 mg/dL: 4 units rapid-acting insulin
• 250–300 mg/dL: 6 units rapid-acting insulin
• 300–350 mg/dL: 8 units rapid-acting insulin

These correction doses are appropriate only when added to scheduled basal insulin, not as monotherapy 1

Critical Safety Considerations

Hypoglycemia Risk

• Basal-bolus regimens carry 4–6 times higher hypoglycemia risk than sliding scale insulin alone (RR 5.75 for glucose ≤70 mg/dL, RR 4.21 for glucose ≤60 mg/dL) 1
• However, sliding scale monotherapy's poor glycemic control causes greater overall morbidity despite lower hypoglycemia rates 1, 2
• The basal-plus approach (versus full basal-bolus) reduces hypoglycemia risk while maintaining superior glycemic control compared to sliding scale alone 1

Dose Adjustments for High-Risk Patients

Reduce initial insulin doses by 50% or use lower end of dosing range (0.1 units/kg/day) for:

• Age >65 years 1
• Renal insufficiency (eGFR <60 mL/min) 1
• Poor or unpredictable oral intake 1
• History of severe hypoglycemia 1

When Sliding Scale Alone Might Be Acceptable

The only scenarios where sliding scale insulin alone is appropriate:

• Patients without established diabetes who have mild stress hyperglycemia 1
• Patients with excellent baseline control (HbA1c <7%, recent glucose <180 mg/dL) on diet or low-dose oral agents alone 1
• Short-term use during steroid tapers or other temporary hyperglycemic states 1

This patient does not meet these criteria since they have established type 2 diabetes requiring treatment 1

Implementation Algorithm

Day 1-2: Initiation

• Calculate total daily dose: 0.2 units/kg for insulin-naive patients 1
• Give 100% as basal insulin (glargine or detemir once daily) 1
• Add correction doses before meals using the scale above 1

Day 3 Onward: Titration

• If correction doses frequently needed (>2 times/day): Increase basal insulin by 10–20% 1
• If hypoglycemia occurs: Reduce basal insulin by 20% 1
• Target glucose: 140–180 mg/dL (not stricter, as this increases hypoglycemia without improving outcomes) 1

For Regular Meals: Advance to Basal-Bolus

• Once eating regularly: Transition to full basal-bolus with 50% of total daily dose as basal, 50% divided among three meals as rapid-acting insulin 1
• Continue correction doses as needed 1

Common Pitfalls to Avoid

• Never use sliding scale regular insulin as monotherapy in patients with established insulin requirements 1
• Do not continue the admission sliding scale unchanged throughout hospitalization—this perpetuates poor control 1
• Avoid premixed insulins (70/30) in the hospital due to unacceptably high hypoglycemia rates 1
• Do not use correction doses alone without basal insulin coverage 1