What is the best course of action for a 24-year-old woman with type 1 diabetes mellitus (T1DM) who presents to the emergency department with hyperglycemia, nausea, and a history of diabetic ketoacidosis (DKA)?

Management of Diabetic Ketoacidosis in a 24-Year-Old with Type 1 Diabetes

This patient should be admitted to the ICU and started on intravenous insulin therapy due to the presence of diabetic ketoacidosis (DKA). 1, 2

Diagnosis of DKA

This 24-year-old woman with type 1 diabetes presents with clear evidence of DKA:

• Elevated blood glucose (350 mg/dL)
• Metabolic acidosis (bicarbonate 18 mEq/L)
• Elevated serum beta-hydroxybutyrate (3.0, normal <0.4)
• Nausea
• History of missed insulin doses (both basal and bolus)
• Previous history of DKA

Treatment Algorithm

Step 1: Fluid Resuscitation

• Already initiated with normal saline
• Continue IV fluid resuscitation with 0.9% NaCl at 15-20 mL/kg/hr for the first hour 1
• Once glucose reaches 250 mg/dL, change to 5% dextrose with 0.45-0.9% NaCl 1

Step 2: Insulin Therapy

• Initiate IV regular insulin with a continuous infusion at 0.1 units/kg/hour 1, 2
• Target glucose reduction of 50-75 mg/dL per hour 2
• Continue IV insulin until DKA resolves (normalization of bicarbonate, closure of anion gap, and beta-hydroxybutyrate <0.3 mmol/L) 2

Step 3: Electrolyte Replacement

• Add potassium to IV fluids when serum level is <5.2 mEq/L (current level 3.3 mEq/L) 2
• Typically add 20-40 mEq/L of potassium (2/3 KCl and 1/3 KPO4) 1
• Monitor electrolytes every 2-4 hours and adjust replacement accordingly

Rationale for ICU Admission

ICU admission is indicated for DKA management because:

1. The patient has significant ketoacidosis (beta-hydroxybutyrate 3.0 mmol/L)
2. Continuous IV insulin infusion requires close monitoring
3. Frequent laboratory assessments are needed
4. Risk of complications including cerebral edema, hypoglycemia, and electrolyte abnormalities 1, 3

The guidelines clearly state that in the presence of ketoacidosis with ketonemia ≥1.5 mmol/L, patients should be transferred to ICU for IV insulin infusion therapy 1.

Transition to Subcutaneous Insulin

Once DKA resolves:

• Administer basal insulin 2-4 hours before stopping IV insulin to prevent recurrence of ketoacidosis 1, 2
• Convert to subcutaneous insulin at 60-80% of the daily IV insulin infusion dose 1
• Resume the patient's home insulin regimen (insulin glargine once daily and insulin lispro with meals) with possible dose adjustments

Important Considerations

• Do not use sliding scale insulin alone as it is strongly discouraged for inpatient management 1, 2
• Monitor blood glucose every 1-2 hours until stable, then every 4-6 hours 2
• Assess for precipitating causes of DKA (infection, stress, etc.)
• Provide education on insulin adherence before discharge

Alternative Approaches

While some recent evidence suggests that subcutaneous insulin may be effective for mild to moderate DKA 4, this patient's presentation warrants the standard approach with IV insulin in an ICU setting due to:

1. Her history of previous DKA episodes
2. Significant ketonemia (beta-hydroxybutyrate 3.0 mmol/L)
3. Metabolic derangements (bicarbonate 18 mEq/L, hyponatremia, hypokalemia)

Discharge Planning

• Begin discharge planning early
• Schedule follow-up appointment within 1 month
• Provide clear written and verbal instructions on insulin dosing
• Establish thresholds for seeking medical attention (glucose >350 mg/dL or <70 mg/dL)
• Address barriers to insulin adherence

By following this approach, you will effectively treat this patient's DKA while minimizing the risk of complications and preventing recurrence.