What should a patient with Type 1 Diabetes Mellitus do if they miss a dose of Lantus (insulin glargine) and present with hyperglycemia, impaired renal function, and metabolic acidosis?

Management of Type 1 Diabetes Patient with Missed Lantus Dose and Hyperglycemia

A patient with Type 1 diabetes who missed their Lantus dose and presents with blood glucose of 721 mg/dL, pH 7.41, HCO3 20 mEq/L, creatinine 1.5 mg/dL, and negative ketones should immediately take their missed Lantus dose and administer a correction dose of rapid-acting insulin based on their insulin sensitivity factor.

Assessment of Current Status

This patient presents with:

• Severe hyperglycemia (BG 721 mg/dL)
• Mild metabolic acidosis (HCO3 20 mEq/L)
• Impaired renal function (Cr 1.5 mg/dL)
• Absence of ketones
• Missed basal insulin (Lantus)

Immediate Management Algorithm

1. Administer missed Lantus dose immediately

   • Lantus (insulin glargine) provides essential basal insulin coverage 1
   • Missing basal insulin in Type 1 diabetes can rapidly lead to insulin deficiency within hours 2

2. Calculate and administer correction dose of rapid-acting insulin

   • Use the patient's insulin sensitivity factor (typically 1 unit lowers glucose by 50 mg/dL)
   • Example calculation: (721 - 150)/50 = approximately 11-12 units of rapid-acting insulin
   • Rapid-acting insulin is preferred for correction doses due to faster onset of action 2

3. Increase fluid intake

   • Drink sugar-free fluids to maintain hydration
   • Consider electrolyte replacement solutions 2
   • Aim for at least 150-200g of carbohydrates daily to prevent starvation ketosis 2

4. Monitor blood glucose frequently

   • Check blood glucose every 2-4 hours until stable 2
   • Be alert for potential delayed hypoglycemia as both basal and correction insulin take effect

Special Considerations for Impaired Renal Function

• Patients with impaired kidney function (elevated creatinine) have a fivefold higher risk of severe hypoglycemia 3
• Consider reducing the usual Lantus dose by 10-20% due to impaired renal clearance
• Monitor more frequently for hypoglycemia, especially 6-12 hours after insulin administration

When to Seek Medical Attention

Immediate medical attention is required if:

• Blood glucose remains >300 mg/dL after 12 hours despite correction doses
• Ketones develop in blood or urine
• Vomiting or inability to maintain fluid intake occurs
• Mental status changes develop
• Difficulty breathing develops 2

Prevention of Future Episodes

1. Never omit insulin in Type 1 diabetes

   • During acute illness, insulin requirements often increase due to stress hormones 2
   • Insulin should be continued even when not eating or during illness 2

2. Create a sick day management plan

   • Have backup insulin supplies
   • Set medication reminders
   • Establish a routine for insulin administration

3. Adjust insulin doses during travel

   • When traveling across time zones, consult with healthcare provider about adjusting insulin schedule 4

Pitfalls to Avoid

1. Do not withhold basal insulin even when not eating

   • Type 1 diabetes patients always require basal insulin to prevent ketoacidosis 2

2. Avoid aggressive correction in patients with renal impairment

   • Patients with elevated creatinine have delayed insulin clearance and increased risk of hypoglycemia 3

3. Do not delay treatment of severe hyperglycemia

   • Prolonged hyperglycemia can progress to diabetic ketoacidosis even if ketones are initially negative 4

4. Do not mix Lantus with other insulins in the same syringe

   • This can alter the pharmacokinetic properties of both insulins 5

By following this approach, the patient should be able to safely correct their hyperglycemia while minimizing the risk of hypoglycemia or progression to diabetic ketoacidosis.