What is the next step in management for an 18‑year‑old female with insulin‑dependent diabetes using an insulin pump, blood glucose 210 mg/dL, nothing by mouth since yesterday morning, and 2+ urine ketones?

Immediate Hospital Evaluation for Diabetic Ketoacidosis (DKA)

This patient requires immediate hospital evaluation and treatment for diabetic ketoacidosis (DKA) - she meets diagnostic criteria with blood glucose >250 mg/dL, 2+ urine ketones, prolonged fasting, and insulin pump use. 1, 2

Why This is DKA

This 18-year-old has the classic presentation:

• Blood glucose 210 mg/dL (>250 mg/dL threshold is for diagnosis, but with 2+ ketones and prolonged fasting, DKA is highly likely)
• 2+ urine ketones (moderate to large ketonuria)
• Nothing by mouth since yesterday morning (>24 hours of inadequate carbohydrate intake)
• Insulin-dependent diabetes with pump (risk for insulin deficiency if pump malfunction)

The combination of ketones with prolonged fasting in an insulin-dependent patient is a medical emergency requiring immediate intervention. 3

Critical First Steps

1. Immediate Actions (Within Minutes)

• Check the insulin pump immediately - verify it's functioning, check insertion site, confirm insulin delivery 4
• Obtain venous blood gas, serum electrolytes, glucose, BUN, creatinine, and calculate anion gap STAT 1, 2
• Measure blood ketones (β-hydroxybutyrate) if available - this is preferred over urine ketones for monitoring 1, 5
• Start IV access immediately 1

2. Assess DKA Severity

The patient needs immediate lab work to determine if this is:

• Mild DKA: pH 7.25-7.30, bicarbonate 15-18 mEq/L
• Moderate DKA: pH 7.00-7.24, bicarbonate 10-15 mEq/L
• Severe DKA: pH <7.00, bicarbonate <10 mEq/L 1, 2

Treatment Protocol

If Mild DKA (Most Likely Scenario)

Subcutaneous insulin can be used - give priming dose of 0.4-0.6 units/kg body weight (half IV bolus, half subcutaneous), then 0.1 unit/kg subcutaneously every hour 1

If Moderate to Severe DKA

1. Disconnect the insulin pump and start IV regular insulin infusion immediately 4

   • Continuous IV insulin infusion is preferred for anything beyond mild DKA 1
   • Use hourly basal rate from pump as starting guide for IV rate 4

2. Fluid resuscitation 1, 2

   • Start with 0.9% normal saline
   • For young adults: typically 1.5 times maintenance requirements (approximately 5 mL/kg/hour)

3. Monitor electrolytes every 2-4 hours 1

   • Potassium replacement is critical (use 1/3 KPO4 and 2/3 KCl)
   • Follow venous pH and anion gap

Critical Pitfall: Starvation Ketosis vs DKA

During acute illness in type 1 diabetes, insulin must NEVER be omitted - the need for insulin continues and often increases despite not eating 3. This patient needs:

• Continued insulin delivery (even with no oral intake)
• 150-200g carbohydrate daily to prevent starvation ketosis 3
• Adequate fluid intake with sodium-containing fluids 3

If she cannot tolerate oral intake due to nausea/vomiting, this requires immediate hospital admission 3.

Resolution Criteria

DKA is resolved when 1, 2:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3

Transition Back to Pump

Once DKA resolves and patient can eat 1:

• Reconnect insulin pump and run basal rate for 2 hours before stopping IV insulin 4
• This overlap prevents rebound hyperglycemia and recurrent ketoacidosis
• Abrupt discontinuation of IV insulin without adequate subcutaneous coverage leads to poor glycemic control

Key Takeaway

The presence of 2+ ketones with prolonged fasting in an insulin pump user is a red flag for impending or established DKA requiring immediate medical evaluation and likely hospitalization. The pump may have malfunctioned (infusion site failure is a significant cause of DKA in pump users 6), or the patient may have inadequate insulin delivery during the fasting period. This is not a situation for outpatient management.