What is the approach to insulin initiation and management in hospitalized patients?

Insulin Initiation and Management in Hospitalized Patients

For hospitalized patients with hyperglycemia, a structured insulin regimen with basal, prandial, and correction components is the preferred treatment approach, while sliding scale insulin alone should be strongly discouraged as it leads to poor glycemic control and increased complications. 1

Glycemic Targets

• Target blood glucose range of 140-180 mg/dL is appropriate for most hospitalized patients, as more intensive targets (<110 mg/dL) have been associated with increased mortality and hypoglycemia risk 1
• For critically ill patients, continuous intravenous insulin infusion is recommended to maintain blood glucose in the 140-180 mg/dL range 1
• For non-critically ill patients, pre-meal glucose targets should generally be <140 mg/dL and random blood glucose <180 mg/dL, as long as these can be safely achieved 1

Insulin Regimen Selection Based on Clinical Setting

Critical Care Setting

• Continuous intravenous insulin infusion is the most effective method for achieving glycemic targets in critically ill patients 1
• Infusions should be administered using validated written or computerized protocols that allow for predefined adjustments based on glycemic fluctuations and insulin dose 1
• More frequent bedside blood glucose testing (every 30 min to 2 hours) is required for safe use of intravenous insulin 1

Non-Critical Care Setting

The insulin regimen should be selected based on the patient's nutritional status:

1. For patients with good nutritional intake:

   • Implement a basal-bolus-correction insulin regimen 1
   • This includes basal insulin (once or twice daily), prandial insulin (before meals), and correction insulin 1
   • For insulin-naive patients: Start with total daily insulin dose of 0.3-0.5 units/kg/day 1
   • Allocate 50% to basal insulin and 50% to prandial insulin divided across three meals 1
   • Lower doses (0.2-0.3 units/kg/day) should be used for elderly patients (>65 years), those with renal failure, or poor oral intake 1

2. For patients with poor or no oral intake (NPO):

   • Use basal insulin with correction insulin (basal-plus regimen) 1
   • Start with lower basal insulin dose (0.1-0.25 units/kg/day) 1
   • Add correction insulin for hyperglycemia before meals or every 6 hours if NPO 1

3. For patients previously on insulin:

   • If patient was on >0.6 units/kg/day at home, reduce total daily dose by 20% during hospitalization to prevent hypoglycemia 1

Specific Insulin Types and Administration

• Basal insulin options include long-acting analogs (glargine, detemir) which are preferred over NPH insulin due to lower hypoglycemia risk 2
• Prandial insulin should use rapid-acting analogs (aspart, lispro, glulisine) administered before meals 2
• Insulin pens can be safely used in the hospital setting but must be strictly labeled "For single patient use only" 1
• Human and analog insulins provide similar glycemic control in the hospital setting 1

Blood Glucose Monitoring

• For patients who are eating: Monitor blood glucose before meals 1
• For patients not eating: Monitor every 4-6 hours 1
• For patients on IV insulin: Monitor every 30 minutes to 2 hours as required 1
• Safety standards prohibiting sharing of lancets and testing materials must be strictly followed 1

Transitioning from IV to Subcutaneous Insulin

When transitioning from IV insulin infusion to subcutaneous insulin:

1. Calculate the 24-hour insulin requirement based on the average hourly infusion rate over the previous 12 hours 1

   • Example: If average rate was 1.5 units/hour, estimated daily dose would be 36 units/24 hours 1

2. Administer first dose of subcutaneous basal insulin 2-4 hours before discontinuing the insulin infusion to prevent rebound hyperglycemia 3

3. Continue IV insulin for 1-2 hours after administering subcutaneous insulin to ensure adequate plasma insulin levels 3

Hypoglycemia Prevention and Management

• A hypoglycemia management protocol should be adopted by each hospital 1
• Treatment regimens should be reviewed and adjusted when blood glucose falls below 100 mg/dL 1
• Modification of insulin regimen is required when blood glucose values are <70 mg/dL 1
• Document all hypoglycemic episodes in the medical record for quality improvement tracking 1

Common Pitfalls to Avoid

• Using sliding scale insulin alone: This reactive approach is ineffective and strongly discouraged 1, 4
• Premixed insulin therapy: Associated with high rates of hypoglycemia and not recommended for hospital use 1
• Abrupt discontinuation of IV insulin: Can lead to rebound hyperglycemia if not properly overlapped with subcutaneous insulin 3
• Holding basal insulin for patients with type 1 diabetes: Basal insulin should never be held for patients with type 1 diabetes, even during care transitions 1
• Overaggressive correction insulin: Recent evidence suggests that less intensive correction insulin (only for BG >260 mg/dL) may be as effective as more intensive correction (for BG >140 mg/dL) when patients are on optimal basal-bolus regimens 5

Special Considerations

• Type 1 diabetes: Always maintain basal insulin, as dosing based solely on premeal glucose levels does not account for basal requirements and increases risk of both hypoglycemia and hyperglycemia 1
• Renal insufficiency: Patients should be treated with lower insulin doses 1
• Transition to discharge: Establish a protocol for resuming home medications 1-2 days before discharge 1
• Diabetes self-management: May be appropriate for competent patients who successfully self-manage at home, have stable consciousness, stable insulin requirements, and adequate skills 1

By following these structured approaches to insulin initiation and management in hospitalized patients, you can optimize glycemic control while minimizing the risks of hypoglycemia and other complications.