What is the recommended blood‑glucose management protocol for hospitalized patients (any ward) who have known diabetes, stress‑related hyperglycaemia, or a random glucose >180 mg/dL, including target glucose range, medication adjustments, insulin regimen, monitoring frequency, and criteria for initiating intravenous regular insulin infusion?

Blood Sugar Management Protocol in Hospital Wards

Initiation Threshold and Target Range

Start insulin therapy when blood glucose persistently exceeds 180 mg/dL (checked on two occasions), and maintain glucose between 140-180 mg/dL for the majority of hospitalized patients, both critically ill and non-critically ill. 1, 2

• Hyperglycemia in hospitalized patients is defined as blood glucose >140 mg/dL, which warrants prompt intervention such as nutritional modifications or medication adjustments 1
• The 140-180 mg/dL target is based on the landmark NICE-SUGAR trial, which demonstrated that intensive glucose control (80-110 mg/dL) resulted in increased mortality and 10-15 fold higher rates of severe hypoglycemia 1, 3
• An admission HbA1c ≥6.5% suggests diabetes preceded hospitalization and should be measured if results from the previous 3 months are unavailable 1, 2

Alternative Targets for Selected Patients

• Tighter control (110-140 mg/dL or 100-180 mg/dL) may be appropriate for highly selected patients such as cardiac surgery patients, those with previously excellent outpatient glycemic control, or patients at centers with extensive nursing support—but only if achievable without significant hypoglycemia 1, 3, 2
• Higher targets (up to 200 mg/dL) are acceptable for terminally ill patients, those with severe comorbidities, or settings where frequent monitoring is not feasible 1

Insulin Regimen Selection

For Non-Critically Ill Patients (General Medicine/Surgery Wards)

Use a basal-bolus-correction insulin regimen for patients with good nutritional intake, or basal insulin plus correction doses for those with poor oral intake or NPO status. 2, 4

Basal-Bolus Regimen (for patients eating meals):

• Basal insulin: Long-acting insulin analogs (glargine or detemir) given once or twice daily, comprising approximately 50% of total daily insulin dose 4, 5
• Bolus insulin: Rapid-acting insulin analogs (aspart, lispro, or glulisine) given before each meal, with the remaining 50% of total daily dose divided among three meals 4, 5
• Correction insulin: Additional rapid-acting insulin based on pre-meal glucose readings 2, 5

Basal-Only Regimen (for NPO or poor oral intake):

• Long-acting basal insulin with correction doses of rapid-acting insulin every 4-6 hours 2, 5
• This prevents the hypoglycemia risk associated with giving prandial insulin when nutritional intake is uncertain 5

Never use sliding-scale insulin as monotherapy—it is ineffective, strongly discouraged by all major guidelines, and associated with poor outcomes. 2, 4, 6

For Critically Ill Patients (ICU)

Continuous intravenous insulin infusion is the preferred method for all critically ill patients requiring glycemic control. 3, 2, 5

• Use a validated computerized or written insulin protocol that allows predefined adjustments based on glycemic fluctuations 3, 2
• Target glucose decline of 50-75 mg/dL per hour when treating severe hyperglycemia 7
• If glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration and double the insulin infusion rate hourly until achieving steady decline 7

Monitoring Frequency

Non-Critically Ill Patients:

• Before each meal for patients eating regular meals 2
• Every 4-6 hours for patients not eating or NPO 3, 2

Critically Ill Patients on IV Insulin:

• Every 30 minutes to 2 hours during continuous IV insulin infusion 3, 2
• This frequent monitoring is the required standard for safe IV insulin use 2

Point-of-Care Testing Considerations:

• Use FDA-approved hospital-calibrated glucose meters, not standard bedside meters 3
• Any glucose result that does not correlate with clinical status should be confirmed through conventional laboratory testing 1

Criteria for IV Insulin Infusion

Initiate continuous IV insulin infusion for:

• All critically ill ICU patients with persistent hyperglycemia >180 mg/dL 3, 2
• Patients with severe hyperglycemia (>400 mg/dL) meeting criteria for DKA or HHS 7
• Perioperative patients during and immediately after major surgery 4

IV Insulin Protocol:

• Initial bolus: 0.15 units/kg body weight for severe hyperglycemia (>400 mg/dL) 7
• Continuous infusion: 0.1 units/kg/hour (typically 5-7 units/hour in adults) 7
• Adjust hourly based on validated protocol to maintain target range 3, 2

Medication Adjustments

Discontinuing Oral Diabetes Medications:

• Multiple guidelines recommend stopping oral diabetes medications at admission due to inpatient factors that increase risk of renal or hepatic failure 6
• However, metformin can be used safely in hospitalized patients with normal kidney function, as there is no proven risk of lactic acidosis 6
• Consider continuing metformin in stable patients without contraindications (renal dysfunction, contrast studies, hemodynamic instability) 6

Transitioning from IV to Subcutaneous Insulin:

Start subcutaneous basal insulin 1-2 hours before stopping IV infusion to prevent rebound hyperglycemia. 7, 2

• Calculate basal insulin dose as 60-80% of total daily IV insulin dose 7
• Use half of the 24-hour IV insulin total as long-acting basal insulin 7
• Divide the other half by 3 for rapid-acting insulin doses before meals 7

Critical Pitfalls to Avoid

Hypoglycemia Prevention:

• Never target glucose <110 mg/dL in general hospital populations—this increases mortality, cardiovascular events, and ICU length of stay 3, 2
• Track all hypoglycemic episodes (<70 mg/dL) in the medical record 3
• Implement a hospital-wide hypoglycemia management protocol 3
• Monitor for hypoglycemia triggers: sudden corticosteroid dose reduction, altered nutritional state, reduced oral intake, new NPO status, inappropriate insulin timing relative to meals 2

Insulin Management Errors:

• Do not stop IV insulin abruptly—ensure 1-2 hour overlap with subcutaneous insulin 7, 2
• Avoid sliding-scale insulin as monotherapy—it excludes basal insulin and is associated with poor outcomes 7, 2, 4
• Reassess insulin regimen if glucose falls below 100 mg/dL and modify when <70 mg/dL unless explained by missed meals 7

Monitoring Complications:

• Monitor mental status closely, as rapid glucose changes may indicate cerebral edema (especially in younger patients) or iatrogenic complications 3, 7
• Confirm adequate renal function before starting insulin if potassium is <3.3 mEq/L 7

Quality Improvement Measures

• Use structured computerized order sets that provide guidance for glycemic management 1
• Electronic insulin order templates improve mean glucose levels without increasing hypoglycemia 1
• Consult specialized diabetes or glucose management teams when available, as they can reduce length of stay and improve outcomes 1, 2
• Consider Joint Commission accreditation program for hospital diabetes care 1