What should the NPH insulin dose be for a patient with type 2 diabetes on Lantus (Insulin Glargine) 27 units, who received 6 units of fast-acting insulin and has a blood glucose level of 344?

NPH Insulin Dosing for Tube-Fed Patient with Steroid-Induced Hyperglycemia

Direct Recommendation

This patient should NOT receive NPH insulin at all—she should continue her Lantus 27 units and have her correctional insulin regimen optimized instead. 1, 2

Clinical Reasoning

Why NPH is Not Indicated Here

• NPH insulin is specifically recommended for steroid-induced hyperglycemia to match the pharmacokinetic profile of glucocorticoids, which peak 4-8 hours after morning administration 1, 3
• There is no mention of steroid therapy in this patient, making NPH an inappropriate choice for basal insulin coverage 1
• The patient already has adequate basal insulin coverage with Lantus 27 units (approximately 0.33 units/kg), which is within the appropriate range for type 2 diabetes 4

The Real Problem: Inadequate Correctional Insulin

• The blood glucose of 344 mg/dL after only 6 units of correctional insulin indicates the correction scale is insufficient, not that basal insulin needs changing 1, 3
• For a patient with this degree of hyperglycemia and insulin resistance (BMI 29), the correction factor should be approximately 1 unit per 20-25 mg/dL above target using the "1800 rule" 3
• A blood glucose of 344 mg/dL should have received approximately 10-12 units of correctional insulin (assuming target of 120-140 mg/dL), not 6 units 3

Appropriate Management Strategy

Optimize the correctional insulin scale:

• Blood glucose 150-200 mg/dL: 2-3 units 3
• Blood glucose 201-250 mg/dL: 4-5 units 3
• Blood glucose 251-300 mg/dL: 6-8 units 3
• Blood glucose 301-350 mg/dL: 10-12 units 3
• Blood glucose >350 mg/dL: 12-14 units and notify provider 3

Consider scheduled prandial coverage for tube feeding:

• With 188 grams of carbohydrates over 24 hours (approximately 63 grams per 8-hour period), consider adding scheduled rapid-acting insulin 4
• Start with 4-6 units of rapid-acting insulin every 8 hours to cover the continuous carbohydrate load, using a ratio of approximately 1 unit per 10-12 grams of carbohydrate 3
• This approach is superior to relying solely on correctional insulin for continuous tube feeding 4

If Basal Insulin Adjustment is Needed

• If fasting glucose remains elevated despite adequate correctional coverage, increase Lantus by 2 units every 3 days until fasting glucose reaches 100-140 mg/dL 1, 2
• The current Lantus dose of 27 units may need titration upward to 0.4-0.5 units/kg (32-40 units) given the degree of hyperglycemia 1

Common Pitfalls to Avoid

• Do not switch from Lantus to NPH without a specific indication (such as steroid therapy)—Lantus provides more consistent 24-hour basal coverage with less nocturnal hypoglycemia than NPH 5, 6
• Do not rely solely on correctional insulin for tube-fed patients—scheduled prandial insulin prevents the "chasing" pattern that leads to persistent hyperglycemia 4
• Monitor blood glucose every 4-6 hours while adjusting the regimen to identify patterns and prevent both hyperglycemia and hypoglycemia 1, 3