Is using a sliding‑scale insulin regimen for meals plus an additional bedtime dose considered outside the standard of care for hospitalized patients with diabetes?

Is Using Sliding-Scale Insulin at Bedtime Outside the Standard of Care for Hospitalized Inpatients?

Yes—using sliding-scale insulin as the sole regimen, including at bedtime, is explicitly condemned by all major diabetes guidelines and is considered outside the standard of care for hospitalized patients. 1

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Why Sliding-Scale Insulin Monotherapy Fails

Sliding-scale insulin treats hyperglycemia reactively after it occurs rather than preventing it, leading to dangerous glucose fluctuations and poor outcomes. 1 Only approximately 38% of patients managed with sliding-scale insulin alone achieve mean glucose <140 mg/dL, whereas 68% reach this target when a scheduled basal-bolus regimen is used. 2, 3 The American Diabetes Association explicitly states that prolonged sole use of sliding-scale insulin in the inpatient hospital setting is strongly discouraged. 1

Randomized controlled trials demonstrate that basal-bolus treatment improved glycemic control and reduced hospital complications compared with sliding-scale insulin in general surgery patients with type 2 diabetes. 1, 2 Treatment failure (defined as >2 consecutive glucose readings >240 mg/dL) occurs in 0–2% of patients on basal-bolus therapy versus ≈19% on sliding-scale insulin alone. 4

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The Standard of Care: Basal-Bolus Insulin Regimen

For Patients Eating Regular Meals

An insulin regimen with basal, prandial, and correction components is the preferred treatment for non-critically ill hospitalized patients with good nutritional intake. 1 This means:

• Basal insulin (glargine, detemir, or degludec) given once daily provides continuous background coverage and suppresses hepatic glucose production. 1
• Prandial insulin (rapid-acting analogs: lispro, aspart, or glulisine) given 0–15 minutes before each meal covers meal-related glucose excursions. 1
• Correction insulin is used as a supplement to scheduled doses—not as a replacement—when pre-meal glucose exceeds predefined thresholds (e.g., 2 units for >250 mg/dL, 4 units for >350 mg/dL). 1, 4

For Patients with Poor Oral Intake or NPO

Basal insulin or a basal-plus-bolus correction insulin regimen is the preferred treatment for non-critically ill hospitalized patients with poor oral intake or those who are NPO. 1 Even when patients are not eating, basal insulin must never be completely withheld because it suppresses hepatic glucose production independent of food intake and prevents hyperglycemia and ketosis. 4, 5

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Specific Concerns About Bedtime Sliding-Scale Insulin

Administering rapid-acting insulin at bedtime as a sole correction dose is explicitly contraindicated because it markedly raises the risk of nocturnal hypoglycemia. 1, 4, 5 The American Diabetes Association specifically warns against this practice. 1, 4

78% of hospitalized patients receiving basal insulin experience nocturnal hypoglycemia (midnight–6 AM), yet 75% receive no basal insulin dose adjustment before the next administration, highlighting a common management gap. 4 When bedtime glucose is elevated (e.g., 221 mg/dL or 279 mg/dL), the appropriate response is to adjust the scheduled basal insulin dose—not to rely on bedtime correction insulin alone. 5

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Evidence-Based Dosing for Hospitalized Patients

Initial Dosing

For insulin-naive patients or those on low-dose insulin at home, start with a total daily dose of 0.3–0.5 units/kg/day, allocating:

• 50% to basal insulin (given once daily)
• 50% to prandial insulin (divided among three meals) 1, 4, 3

For high-risk patients (age >65 years, renal impairment, poor oral intake), use a lower starting dose of 0.1–0.25 units/kg/day to minimize hypoglycemia risk. 1, 4

Titration Protocol

• Basal insulin: Increase by 2 units every 3 days if fasting glucose is 140–179 mg/dL; increase by 4 units every 3 days if fasting glucose is ≥180 mg/dL. Target fasting glucose: 80–130 mg/dL. 1, 4
• Prandial insulin: Increase each meal dose by 1–2 units (≈10–15%) every 3 days based on 2-hour post-prandial glucose. Target post-prandial glucose: <180 mg/dL. 1, 4

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Monitoring Requirements

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

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Hypoglycemia Management

Treat any glucose <70 mg/dL immediately with 15 g of fast-acting carbohydrate, recheck in 15 minutes, and repeat if needed. 1, 4 If hypoglycemia occurs without an obvious cause, reduce the implicated insulin dose by 10–20% immediately before the next administration. 1, 4

Every hypoglycemic episode must be documented in the medical record and tracked for quality-improvement purposes. 1, 4 A hypoglycemia management protocol should be adopted and implemented by each hospital or hospital system. 1

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Common Pitfalls to Avoid

• Never use sliding-scale insulin as monotherapy in hospitalized patients—this approach is condemned by all major diabetes guidelines. 1, 3
• Never give rapid-acting insulin at bedtime as a sole correction dose—this markedly increases nocturnal hypoglycemia risk. 1, 4, 5
• Do not delay transition to scheduled insulin when glucose values are consistently >180 mg/dL—this prolongs exposure to severe hyperglycemia and increases complication risk. 4
• Do not rely solely on correction doses without adjusting scheduled basal and prandial insulin—this perpetuates inadequate control. 1, 4

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Special Considerations

Transitioning from IV to Subcutaneous Insulin

When discontinuing intravenous insulin, administer subcutaneous basal insulin 2–4 hours before stopping the IV infusion to prevent rebound hyperglycemia and recurrent ketoacidosis. 1, 4 Convert to basal insulin at 60–80% of the daily infusion dose. 1

Perioperative Management

Reduce the basal insulin dose by approximately 25% the evening before surgery to achieve target glucose levels with decreased hypoglycemia risk. 4 While the patient is NPO perioperatively, monitor glucose every 2–4 hours and treat with short- or rapid-acting insulin as needed. 4

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Expected Clinical Outcomes

With properly implemented basal-bolus therapy, ≈68% of patients achieve mean glucose <140 mg/dL, compared with ≈38% on sliding-scale alone. 2, 3 Basal-bolus therapy does not increase hypoglycemia incidence when correctly applied versus sliding-scale monotherapy. 2 However, when improperly implemented, basal-bolus therapy carries a 4–6 times higher hypoglycemia risk than sliding-scale insulin alone (RR 5.75; 95% CI 2.79–11.83 for glucose ≤70 mg/dL). 6, 3

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In summary, using sliding-scale insulin with meals and at bedtime as the sole regimen is outside the standard of care. The bedtime dose is particularly problematic because rapid-acting insulin at bedtime significantly increases nocturnal hypoglycemia risk. The standard of care requires scheduled basal insulin with prandial insulin for eating patients, or basal-plus-correction insulin for NPO patients—with correction insulin serving only as a supplement to scheduled doses, never as monotherapy.