What is the initial insulin dose for a patient with severe hyperglycemia (A1c of 15)?

Initial Insulin Dosing for Severe Hyperglycemia (A1c 15%)

For a patient with an A1c of 15%, start with basal insulin at 0.2 units/kg/day (or 10 units if weight-based dosing is not feasible) PLUS prandial insulin at 4 units before the largest meal, given the severe hyperglycemia and likely symptomatic presentation. 1, 2, 3

Rationale for Immediate Basal-Bolus Therapy

• An A1c of 15% represents extreme hyperglycemia requiring aggressive insulin therapy, as patients with A1c ≥9-10% or blood glucose ≥300-350 mg/dL with symptomatic or catabolic features should start basal-bolus insulin immediately rather than basal insulin alone 4, 1, 2
• The American Diabetes Association recommends that patients with severe hyperglycemia (A1c >10-12%) with symptomatic or catabolic features require immediate basal-bolus insulin therapy 2, 3
• At this level of hyperglycemia, non-insulin agents alone will not achieve adequate control, as most oral agents reduce A1c by only 1% 1

Specific Dosing Algorithm

Basal Insulin Component

• Start with 0.2 units/kg/day of long-acting insulin (insulin glargine/Lantus) once daily at the same time each day 2, 3, 5
• Alternative: If weight-based dosing is not feasible, start with 10 units once daily 2, 3
• For patients with more severe hyperglycemia, consider higher initial doses of 0.3-0.4 units/kg/day 2

Prandial Insulin Component

• Add rapid-acting insulin (aspart, lispro, or glulisine) at 4 units before the largest meal 1, 2
• Alternative calculation: Use 10% of the basal insulin dose as the starting prandial dose 1, 2
• If symptoms persist or glucose remains >300 mg/dL, add prandial insulin before additional meals 1

Titration Protocol

Basal Insulin Adjustments

• Increase basal insulin by 4 units every 3 days if fasting glucose ≥180 mg/dL 1, 2
• Increase by 2 units every 3 days if fasting glucose is 140-179 mg/dL 1, 2
• Target fasting glucose: 80-130 mg/dL 1, 2, 3

Prandial Insulin Adjustments

• Increase prandial insulin by 1-2 units or 10-15% twice weekly based on postprandial glucose readings 1, 2
• Monitor glucose 2-4 hours after meals to assess effectiveness 1

Foundation Therapy Considerations

• Continue or initiate metformin unless contraindicated, as it remains the foundation of type 2 diabetes therapy even when intensifying insulin 1, 2, 3
• Consider adding an SGLT2 inhibitor for cardiovascular benefits and to reduce total insulin requirements 1
• Discontinue sulfonylureas when starting complex insulin regimens to reduce hypoglycemia risk 1, 2

Critical Monitoring Requirements

• Check fasting glucose daily during titration phase 2, 3
• Monitor for hypoglycemia, especially 2-4 hours after prandial insulin administration 1
• Reassess every 2-3 months with A1c measurement 4, 1
• If hypoglycemia occurs, reduce insulin dose by 10-20% 2

Common Pitfalls to Avoid

• Do NOT delay insulin intensification by trying additional oral agents at this A1c level—prolonged severe hyperglycemia (A1c >9%) increases complication risk 1
• Do NOT rely solely on basal insulin at this level of hyperglycemia—prandial coverage is essential 1, 2
• Do NOT use sliding scale insulin alone without optimizing basal insulin first, as this approach is ineffective for long-term management 4, 1
• Do NOT continue escalating basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia with prandial insulin 1, 2

Special Considerations for Hospitalized Patients

• If the patient is hospitalized, insulin therapy should be initiated for persistent hyperglycemia starting at a threshold ≥180 mg/dL, with a target glucose range of 140-180 mg/dL 4
• For hospitalized insulin-naive patients, start with a total daily dose of 0.3-0.5 units/kg, with half as basal insulin 2
• Use validated written or computerized protocols for insulin administration 4

Patient Education Essentials

• Teach proper insulin injection technique and site rotation 2
• Educate on recognition and treatment of hypoglycemia 4, 2
• Provide self-monitoring of blood glucose training 4, 2
• Explain "sick day" management rules 2

Expected Outcomes

• Research suggests that short-term intensive insulin therapy in newly diagnosed patients with severe hyperglycemia can achieve remission rates of 44-51% at 1 year 6
• Patients with A1c >10% typically require insulin therapy to prevent metabolic decompensation and achieve rapid glycemic control 1