What is the recommended increase in NPH (Neutral Protamine Hagedorn) insulin for a patient with increased tube feeding from 60 ml/hr to 90 ml/hr, currently receiving 68 units of NPH insulin?

Adjusting NPH Insulin for Increased Tube Feeding Rate

For a patient whose tube feeding has increased from 60 ml/hr to 90 ml/hr while receiving 68 units of NPH insulin, the NPH insulin dose should be increased to approximately 102 units (a 50% increase in proportion to the tube feeding rate increase). 1

Calculation Rationale

• The tube feeding rate has increased by 50% (from 60 ml/hr to 90 ml/hr) 1
• For patients receiving continuous tube feedings, insulin requirements are directly proportional to carbohydrate intake 1
• Since the carbohydrate load has increased by 50%, the NPH insulin dose should be increased proportionally 1

Administration Recommendations

• NPH insulin should be administered twice or three times daily (every 8 or 12 hours) to cover nutritional needs for continuous tube feeding 1
• If using twice-daily dosing, divide the 102 units as approximately 68 units in the morning and 34 units in the evening 1
• If using three-times-daily dosing, divide the total dose into equal portions of approximately 34 units every 8 hours 1

Monitoring and Adjustments

• Blood glucose should be monitored frequently (every 4-6 hours) after making this insulin adjustment 1
• Correctional insulin should be administered subcutaneously every 6 hours using human regular insulin or every 4 hours using rapid-acting insulin 1
• Further adjustments to the NPH dose may be needed based on blood glucose patterns 1

Important Considerations

• If enteral nutrition is interrupted for any reason, a 10% dextrose infusion must be started immediately at 50 ml/hr to prevent hypoglycemia 1
• The risk of hypoglycemia increases with higher insulin doses, particularly between midnight and 6:00 AM 1
• Commercially available enteral formulas contain variable amounts of carbohydrates, so the exact insulin adjustment may need to be fine-tuned based on the specific formula being used 1

Pitfalls to Avoid

• Failing to coordinate insulin administration with tube feeding schedules can lead to dangerous glycemic excursions 1
• Not adjusting insulin promptly when tube feeding rates change can result in persistent hyperglycemia 1
• Overlooking the need for immediate dextrose infusion if tube feeding is interrupted can lead to severe hypoglycemia 1
• Not monitoring blood glucose frequently enough after insulin dose adjustments can miss early signs of hypo- or hyperglycemia 1