What are the appropriate doses of glargine and lispro for an 85 kg male with hyperglycemia and NPO status?

Insulin Dosing for NPO Patient with Severe Hyperglycemia

Immediate Glargine Dosing Recommendation

For this 85 kg male with blood glucose of 312 mg/dL who is NPO, start insulin glargine at 17 units subcutaneously once daily (0.2 units/kg/day). 1

The FDA-approved starting dose for type 2 diabetes patients not currently on insulin is 0.2 units/kg or up to 10 units once daily 1. Given the severe hyperglycemia (312 mg/dL), use the weight-based calculation at the higher end of the recommended range:

• 85 kg × 0.2 units/kg = 17 units glargine once daily 2, 3, 1

Lispro Dosing for NPO Status

Do NOT give scheduled lispro while the patient is NPO. 1

• Lispro is a rapid-acting prandial insulin designed to cover meals 2
• Since the patient is NPO (nothing by mouth), there is no nutritional intake to cover with mealtime insulin 2
• Use lispro only as correctional (sliding scale) insulin for blood glucose >180 mg/dL 3, 4

Correctional Lispro Dosing Algorithm:

• Blood glucose 180-220 mg/dL: 2-4 units lispro 3
• Blood glucose 221-260 mg/dL: 4-6 units lispro 3
• Blood glucose 261-300 mg/dL: 6-8 units lispro 3
• Blood glucose >300 mg/dL: 8-10 units lispro 3

Check blood glucose every 4-6 hours while NPO and administer correctional lispro as needed 3, 4.

Titration Strategy

Increase glargine by 4 units every 3 days if fasting glucose remains ≥180 mg/dL, or by 2 units every 3 days if fasting glucose is 140-179 mg/dL, targeting 80-130 mg/dL. 2, 3

• Monitor fasting blood glucose daily during titration 2, 3
• If hypoglycemia occurs (glucose <80 mg/dL), reduce glargine dose by 10-20% immediately 2, 3
• Continue titrating until fasting glucose reaches 80-130 mg/dL 2, 3

When Patient Resumes Eating

Once the patient is no longer NPO and begins eating:

• Continue the titrated glargine dose 2, 3
• Add lispro 4 units before the largest meal (or 10% of current glargine dose) 2, 3
• Titrate prandial lispro by 1-2 units every 3 days based on 2-hour postprandial glucose readings 3
• Add lispro to additional meals if postprandial hyperglycemia persists 2, 3

Critical Pitfalls to Avoid

• Never give scheduled prandial insulin to NPO patients - this causes severe hypoglycemia 1
• Do not delay basal insulin initiation - blood glucose of 312 mg/dL requires immediate intervention 2
• Avoid overbasalization - if glargine exceeds 0.5 units/kg/day (>42 units for this patient) without achieving target, add prandial insulin rather than continuing to escalate basal insulin 2, 3
• Do not mix or dilute glargine with any other insulin or solution 1
• Rotate injection sites within the same region to prevent lipodystrophy 1

Monitoring Requirements

• Check fasting blood glucose daily during titration 2, 3
• Check blood glucose every 4-6 hours while NPO 3, 4
• Reassess insulin regimen at every clinical visit 3
• Watch for signs of hypoglycemia, especially if oral intake remains poor 2, 3