What is the protocol for discontinuing an intravenous (IV) insulin infusion?

Protocol for Discontinuing an Intravenous (IV) Insulin Infusion

When discontinuing an intravenous insulin infusion, administer subcutaneous basal insulin 2 hours before stopping the IV infusion to prevent rebound hyperglycemia and maintain glycemic control. 1

Transition Requirements

Before initiating the transition from IV to subcutaneous insulin:

• Ensure blood glucose levels are stable for at least 24 hours 1
• Confirm the patient has resumed oral feeding 1
• Verify the IV insulin infusion rate is <3 U/h (higher rates indicate insulin resistance and may require special consideration) 1

Transition Protocol

Step 1: Calculate Subcutaneous Insulin Dose

• Calculate the total daily subcutaneous insulin dose based on the insulin infusion rate during the previous 6-8 hours when stable glycemic goals were achieved 1
• The recommended conversion is 60-80% of the total daily IV insulin requirement 1
  • Studies show that using 50-59% of the 24-hour IV insulin requirements may achieve the highest rate of blood glucose concentrations in target range 2
  • For elderly patients or those with high IV insulin requirements, consider using the lower end of the range to avoid hypoglycemia 3

Step 2: Distribute the Insulin Dose

• Divide the calculated total daily dose:
  • 50% as basal insulin (long-acting)
  • 50% as prandial insulin (rapid-acting) divided between meals 1, 3

Step 3: Time the Transition

• Administer the first dose of subcutaneous basal insulin 2 hours before discontinuing the IV insulin infusion 1
• The optimal timing for basal insulin administration is around 8:00 PM (20:00) 1
• If transition occurs earlier, adjust the dose accordingly and give the second injection at 8:00 PM 1

Step 4: Initiate Prandial Insulin

• Administer the first dose of rapid-acting insulin at the first meal 1
• Adjust the dose based on the carbohydrate content of the meal 1

Special Considerations

Type 1 Diabetes

• All patients with type 1 diabetes must receive basal insulin with correction components 1
• Never discontinue insulin completely in patients with type 1 diabetes to avoid diabetic ketoacidosis

Insulin Pump Users

• Reconnect the personal insulin pump as soon as the patient can manage autonomously 1
• If the patient cannot manage the pump, initiate a basal-bolus subcutaneous insulin regimen 1

Monitoring After Transition

• Check blood glucose before meals and at bedtime
• Monitor for hypoglycemia (<70 mg/dL or <3.9 mmol/L) 1, 4
• If hypoglycemia occurs, review and adjust the insulin regimen 4
• Continue monitoring for at least 48 hours after transition, as glycemic control may deteriorate rapidly 5

Common Pitfalls to Avoid

1. Delayed basal insulin administration: Failing to administer basal insulin 2 hours before stopping IV insulin can lead to rebound hyperglycemia 1

2. Incorrect dose calculation: Using too high a percentage of the IV insulin requirement can cause hypoglycemia, while too low a percentage can result in hyperglycemia 2, 6

3. Ignoring patient factors: Age, renal function, and nutritional status affect insulin requirements and should be considered when calculating doses 3

4. Inadequate monitoring: Failure to monitor blood glucose frequently after transition can miss early dysglycemia 5

5. Not adjusting for meal intake: Prandial insulin doses should be adjusted based on actual carbohydrate intake, especially if meals are small or irregular 1

By following this structured protocol, healthcare providers can safely transition patients from IV to subcutaneous insulin while maintaining glycemic control and minimizing the risk of both hypoglycemia and hyperglycemia.