What is the initial dose of regular insulin for a patient with severe hyperglycemia (glucose level of 350) and an A1C above 15, weighing 73.2 kg?

Initial Insulin Dosing for Severe Hyperglycemia

For a patient with severe hyperglycemia (glucose 350 mg/dL) and A1C above 15 weighing 73.2 kg, the initial regular insulin dose should be 0.1 units/kg/hour as an intravenous infusion, which equals approximately 7.3 units/hour, or if using subcutaneous insulin, start with a total daily dose of 0.5-0.6 units/kg/day (36-44 units), with 50% as basal and 50% as prandial insulin.

Initial Management Approach

• For patients with severe hyperglycemia (glucose ≥300-350 mg/dL) and very high A1C (≥10-12%), immediate insulin therapy is strongly recommended 1
• With glucose of 350 mg/dL and A1C above 15%, this patient has severe hyperglycemia requiring prompt insulin initiation rather than oral agents 1, 2
• For this 73.2 kg patient, the recommended initial approach depends on clinical presentation:
  • If symptomatic with polyuria, polydipsia, or weight loss: start with basal insulin while initiating metformin 1
  • If showing signs of metabolic decompensation: use intravenous insulin initially 1

Dosing Calculations

• For intravenous insulin in severe hyperglycemia:

  • Initial dose: 0.1 units/kg/hour = 7.3 units/hour 1, 2
  • Monitor glucose every 1-2 hours and adjust insulin rate to achieve target glucose of 140-180 mg/dL 1

• For subcutaneous insulin regimen:

  • Total daily insulin dose: 0.5-0.6 units/kg/day = 36-44 units total 1, 2
  • Distribute as 50% basal (18-22 units) and 50% prandial (18-22 units divided between meals) 1
  • Basal insulin: Start with 18-22 units of glargine once daily or NPH twice daily 1, 2
  • Prandial insulin: Start with 6-7 units of regular insulin before each meal 1, 2

Titration Protocol

• Increase basal insulin by 2 units every 3 days until fasting glucose reaches target (70-130 mg/dL) without hypoglycemia 2
• Adjust prandial insulin by 1-2 units or 10-15% twice weekly based on post-meal glucose readings 1
• If hypoglycemia occurs, reduce the corresponding insulin dose by 10-20% 1, 2
• Monitor blood glucose before meals and at bedtime to guide adjustments 2

Important Considerations

• Assess for ketosis/ketoacidosis, which would necessitate more aggressive insulin therapy and fluid resuscitation 1, 3
• Screen for hyperosmolar hyperglycemic state if glucose exceeds 600 mg/dL 1, 3
• Continue metformin (if not contraindicated) alongside insulin therapy to improve insulin sensitivity 1, 2
• Provide comprehensive education on insulin administration, glucose monitoring, and hypoglycemia management 1, 2

Monitoring and Follow-up

• Check glucose levels frequently during initial management - every 1-2 hours if intravenous insulin is used, or 4 times daily with subcutaneous regimen 1, 2
• Once glucose levels stabilize below 300 mg/dL on intravenous insulin, transition to subcutaneous insulin with overlap to prevent rebound hyperglycemia 1
• Reassess A1C after 3 months of therapy 1, 2

This patient's severe hyperglycemia requires immediate insulin therapy rather than stepwise oral agent approach. The high A1C above 15% indicates prolonged, significant hyperglycemia that will respond best to insulin, with the goal of preventing acute complications and gradually improving glycemic control.