Basal-Bolus Insulin Regimen Is Superior to Sliding-Scale for Non-ICU Inpatients

For adult patients with diabetes not requiring ICU management, use a scheduled basal-bolus insulin regimen with a starting total daily dose of 0.3–0.5 units/kg/day (split 50% basal, 50% prandial), and abandon sliding-scale insulin as monotherapy—it is explicitly condemned by major diabetes guidelines and achieves adequate glycemic control in only 38% of patients versus 68% with basal-bolus therapy. 1, 2

Why Sliding-Scale Insulin Fails

Sliding-scale insulin (SSI) used alone is ineffective because it reacts to hyperglycemia after it occurs rather than preventing it, creating dangerous glucose fluctuations between hyper- and hypoglycemia 1, 3. Randomized trials demonstrate that SSI monotherapy leaves 14–19% of patients with persistent blood glucose >240 mg/dL despite escalating correction doses, and treatment failure rates are 10-fold higher than with basal-bolus regimens 2, 4. The American Diabetes Association explicitly states that SSI is "not acceptable as the single regimen" because it results in "undesirable hypoglycemia and hyperglycemia and increased risk of hospital complications" 1.

Initial Dosing Algorithm for Basal-Bolus Therapy

Standard-Risk Patients

Total daily dose (TDD): 0.3–0.5 units/kg/day 1, 5
Basal insulin (glargine or detemir): 50% of TDD, given once daily 1, 5
Prandial insulin (lispro, aspart, or glulisine): 50% of TDD, divided equally before three meals 1, 5
Example: For a 70 kg patient → TDD = 21–35 units → Basal = 11–18 units once daily, Prandial = 4–6 units before each meal 5

High-Risk Patients (Age >65, Renal Impairment, Poor Oral Intake)

Reduced TDD: 0.1–0.25 units/kg/day to minimize hypoglycemia risk 1, 5
Example: For a 70 kg elderly patient → TDD = 7–18 units → Basal = 4–9 units, Prandial = 1–3 units per meal 5

Patients on High-Dose Home Insulin (≥0.6 units/kg/day)

Reduce TDD by 20% upon hospital admission to prevent hypoglycemia 1, 5

Correction Insulin: Adjunct, Not Replacement

Correction doses supplement—never replace—scheduled basal and prandial insulin 1, 3. Use this simplified protocol:

Pre-meal glucose >250 mg/dL: Add 2 units rapid-acting insulin 1
Pre-meal glucose >350 mg/dL: Add 4 units rapid-acting insulin 1

Frequent need for correction doses signals inadequate scheduled insulin; increase basal or prandial components rather than relying on reactive corrections 1, 3.

Titration Protocols

Basal Insulin Adjustment

Fasting glucose 140–179 mg/dL: Increase by 2 units every 3 days 1
Fasting glucose ≥180 mg/dL: Increase by 4 units every 3 days 1
Target: Fasting glucose 80–130 mg/dL 1

Prandial Insulin Adjustment

Increase each meal dose by 1–2 units (10–15%) every 3 days based on 2-hour postprandial glucose 1
Target: Postprandial glucose <180 mg/dL 1

Hypoglycemia Response

If glucose <70 mg/dL without clear cause, reduce the implicated dose by 10–20% immediately 1

Monitoring Requirements

Patients eating regular meals: Check glucose before each meal and at bedtime (4 times daily) 1
Patients NPO or with poor intake: Check glucose every 4–6 hours 1
Daily fasting glucose is essential during titration to guide basal adjustments 1

Clinical Outcomes: Basal-Bolus vs. Sliding-Scale

Randomized controlled trials consistently demonstrate superiority of basal-bolus therapy:

68% achieve mean glucose <140 mg/dL with basal-bolus vs. 38% with SSI alone 2, 4
Treatment failure (>2 consecutive readings >240 mg/dL): 0–2% with basal-bolus vs. 19% with SSI 4
Hospital complications reduced: Lower rates of postoperative wound infection, pneumonia, bacteremia, acute renal failure, and respiratory failure 1, 6
Hypoglycemia rates comparable when basal-bolus is correctly implemented (no increase vs. SSI) 2, 4

Critical Pitfalls to Avoid

Never use SSI as monotherapy—it is condemned by all major diabetes guidelines and shown to be inferior 1, 2, 3
Do not delay adding prandial insulin when daytime glucose repeatedly exceeds 180 mg/dL; this clearly indicates need for mealtime coverage 1
Do not give rapid-acting insulin at bedtime as a sole correction dose—this markedly raises nocturnal hypoglycemia risk 1
Do not continue escalating basal insulin beyond 0.5–1.0 units/kg/day without addressing postprandial hyperglycemia; this causes "overbasalization" with increased hypoglycemia and suboptimal control 1
Do not leave SSI orders unchanged throughout hospitalization when glucose remains uncontrolled—this is the most frequent error in inpatient insulin management 7

Alternative Regimen: Basal-Plus for Simplicity

For patients with unpredictable meal intake, a basal-plus regimen (basal insulin once daily + correction doses only before meals) achieves glycemic control similar to full basal-bolus therapy 4. This approach:

Uses the same basal insulin dose as basal-bolus 4
Provides correction insulin only when pre-meal glucose >140 mg/dL (or >260 mg/dL for less intensive approach) 4, 8
Results in identical mean daily glucose and no difference in hypoglycemia rates compared to basal-bolus 4, 8
Reduces complexity while maintaining efficacy 4

However, basal-plus still requires scheduled basal insulin—it is not the same as SSI monotherapy 4.

Insulin Selection

Preferred insulins are analogs over human insulins because they more closely mimic physiologic insulin secretion and carry lower hypoglycemia risk 7, 3:

Basal: Glargine or detemir (once daily) 1, 7
Prandial: Lispro, aspart, or glulisine (0–15 minutes before meals) 1, 7

Human insulins (NPH, regular) are acceptable alternatives but have higher hypoglycemia rates, particularly in elderly patients 1.

Target Glucose Ranges

Non-critically ill hospitalized patients: 140–180 mg/dL 1, 7
Fasting/pre-meal glucose: 80–130 mg/dL 1
Postprandial glucose: <180 mg/dL 1

More stringent targets (110–140 mg/dL) may be appropriate for select stable patients if achievable without significant hypoglycemia 1.

What is the preferred subcutaneous insulin regimen (basal‑bolus versus sliding‑scale) and initial dosing for an adult patient not requiring intensive‑care‑unit management?

Help us tailor your experience