What are the recommended NPH doses and correction scale for a Type 3c (Total Parenteral Nutrition) admitted patient with influenza on continuous tube feeding (TF), who is insulin sensitive and currently requires 13 units of NPH (Neutral Protamine Hagedorn) plus 29 units of short-acting insulin during the day and 18 units of NPH plus 12 units of short-acting insulin overnight?

NPH Insulin Dosing for Type 3c Diabetes Patient on Continuous Tube Feeding

For this insulin-sensitive Type 3c diabetes patient on continuous tube feeding requiring substantial insulin coverage, consolidate the current regimen to NPH insulin administered every 8 hours (three times daily) with a starting total daily dose of approximately 60-65 units divided as follows: 22 units at 8 AM, 22 units at 4 PM, and 18 units at midnight, plus correctional insulin every 4-6 hours using a conservative scale of 1 unit for every 50 mg/dL above 150 mg/dL. 1

Rationale for NPH Dosing Strategy

Converting Current Insulin Requirements to NPH Schedule

• Your patient currently requires 42 units of short-acting insulin daily (29 units daytime + 12 units overnight) plus 31 units of NPH (13 units day + 18 units night), totaling 73 units per day 1

• For continuous tube feeding, the ADA specifically recommends NPH insulin administered every 8 or 12 hours to cover nutritional needs, with most specialists favoring the every 8-hour approach for more stable coverage 1

• Calculate the nutritional insulin component as approximately 1 unit per 10-15 grams of carbohydrate in the tube feeding formula, then add this to basal requirements 1

• Since this patient is insulin-sensitive yet requires high doses (likely due to acute illness with influenza), start conservatively at 85% of current total daily dose to prevent hypoglycemia: approximately 62 units total 1

Specific NPH Dosing Schedule

• Morning dose (8 AM): 22 units - This covers the highest metabolic demand period and daytime nutritional needs 1

• Afternoon dose (4 PM): 22 units - This provides coverage through evening and early night when tube feeding continues 1

• Midnight dose: 18 units - This is intentionally lower (approximately 80% of daytime doses) as overnight insulin sensitivity typically increases and hypoglycemia risk peaks between midnight and 6 AM 1

• The distribution reflects that 75% of hypoglycemic episodes occur with basal insulin use, with peak incidence between midnight and 6 AM, necessitating a more conservative overnight approach 1

Correctional Insulin Scale

Conservative Correction Protocol for Insulin-Sensitive Patient

• Use rapid-acting insulin every 4 hours (preferred) or regular human insulin every 6 hours for corrections 1

• Starting correction scale for insulin-sensitive patient:

  • Blood glucose 150-200 mg/dL: 1 unit
  • Blood glucose 201-250 mg/dL: 2 units
  • Blood glucose 251-300 mg/dL: 3 units
  • Blood glucose 301-350 mg/dL: 4 units
  • Blood glucose >350 mg/dL: 5 units and notify physician 1

• This represents 1 unit for every 50 mg/dL above target (150 mg/dL), which is appropriate for insulin-sensitive patients 2

• For patients with higher insulin resistance, the scale would be 1 unit per 40 mg/dL above target, but given the explicit insulin sensitivity, use the more conservative 1:50 ratio 2

Monitoring and Adjustment Protocol

Frequent Glucose Monitoring Requirements

• Monitor blood glucose every 2-4 hours while on continuous tube feeding to guide insulin adjustments 1, 3

• Target blood glucose range should be 80-180 mg/dL for hospitalized patients 1, 2

• Pay particular attention to overnight values (midnight, 3 AM, 6 AM) given the high risk of nocturnal hypoglycemia in insulin-sensitive patients 1

Dose Adjustment Algorithm

• If hypoglycemia occurs (<70 mg/dL): Determine the cause; if no clear reason exists, reduce the corresponding NPH dose by 10-20% 1, 3

• For persistent hyperglycemia: Increase the relevant NPH dose by 2 units every 3 days until target glucose is achieved without hypoglycemia 1, 3

• If correction insulin requirements exceed 20 units per day: Consider adding this amount to the NPH regimen or switching to intravenous regular insulin in the parenteral nutrition solution 1

Critical Safety Considerations

Preventing Hypoglycemia in High-Risk Patient

• If tube feeding is interrupted: Immediately start 10% dextrose infusion to prevent hypoglycemia, as NPH has a duration of action of 12-18 hours and will continue working even without nutritional intake 1, 3

• This patient has multiple hypoglycemia risk factors: insulin sensitivity, acute illness (influenza), and continuous tube feeding that may be interrupted 1, 4

• 84% of patients who experience severe hypoglycemia (<40 mg/dL) had a preceding episode of mild hypoglycemia (<70 mg/dL) during the same admission, making early detection crucial 1

• Despite recognition of hypoglycemia, 75% of patients do not have their basal insulin dose adjusted before the next administration—avoid this common pitfall by proactively reducing doses after any hypoglycemic event 1

Type 1 Diabetes Consideration

• If this is Type 3c diabetes with absolute insulin deficiency (similar to Type 1), the patient must continue receiving basal insulin even if tube feeding is discontinued to prevent diabetic ketoacidosis 1

• In this scenario, maintain at least 50% of the basal insulin dose and start dextrose infusion if nutrition is held 1

Adjustments for Influenza Recovery

Anticipating Changing Insulin Requirements

• As the acute illness (influenza) resolves, insulin requirements typically decrease by 20-40% over 3-5 days 5, 2

• Monitor for improving glucose control and proactively reduce NPH doses by 10-20% if fasting or pre-correction glucose values trend below 120 mg/dL 1, 5

• The correction scale may need to be liberalized (increased sensitivity factor to 1:60 or 1:70) as illness resolves and insulin sensitivity improves 2