What is the appropriate management for a patient with type 1 diabetes presenting with diabetic ketoacidosis, characterized by metabolic acidosis, ketonuria, and hyperglycemia?

Management of Diabetic Ketoacidosis in Type 1 Diabetes

This patient meets criteria for moderate-to-severe DKA and requires immediate IV fluid resuscitation with isotonic saline at 15-20 mL/kg/hour, followed by continuous IV regular insulin infusion at 0.1 units/kg/hour, with aggressive potassium monitoring and replacement once levels are confirmed ≥3.3 mEq/L. 1, 2

Diagnostic Confirmation

Your patient clearly has DKA based on:

• Blood glucose 315 mg/dL (>250 mg/dL required) 2, 3
• Venous pH 7.29 (<7.3 required, classifies as moderate DKA with pH 7.00-7.24 range) 2, 3
• Bicarbonate 11 mEq/L (<15 mEq/L required, classifies as moderate with 10-15 range) 2, 3
• Ketones 2.71 mmol/L (ketonemia present, >0.5 mmol/L diagnostic) 1, 3
• Anion gap 22 mEq/L (elevated, >10-12 diagnostic) 3

This is moderate DKA requiring intensive management. 2, 3

Immediate Initial Management (First Hour)

Fluid Resuscitation

• Start isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour to restore circulatory volume and tissue perfusion. 1, 2
• For an average 70 kg adult, this equals approximately 1-1.5 liters in the first hour. 2
• Subsequent fluid choice depends on hydration status, serum electrolytes, and urine output. 2, 3

Critical Laboratory Assessment

Before starting insulin, you MUST check serum potassium immediately. 1, 2

• If K+ <3.3 mEq/L: DO NOT start insulin—this is an absolute contraindication. 1, 2

  • Delay insulin and aggressively replace potassium with 20-40 mEq/L in IV fluids until K+ ≥3.3 mEq/L. 1, 2
  • Obtain ECG to assess for cardiac effects of hypokalemia. 1
  • Insulin will drive potassium intracellularly and can cause life-threatening arrhythmias and death. 1, 2, 4

• If K+ 3.3-5.5 mEq/L: Start insulin AND add 20-30 mEq/L potassium to IV fluids (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed. 1, 2, 3

• If K+ >5.5 mEq/L: Start insulin but withhold potassium initially; monitor closely as levels will drop rapidly with insulin therapy. 2

Insulin Therapy Protocol

Once K+ ≥3.3 mEq/L confirmed:

• Give IV bolus of 0.1 units/kg regular insulin 1, 4
• Start continuous IV infusion at 0.1 units/kg/hour regular insulin 1, 2, 4
• Target glucose decline: 50-75 mg/dL per hour 1, 2

If glucose does not fall by 50 mg/dL in the first hour:

• Verify adequate hydration status 1
• Double the insulin infusion rate every hour until achieving steady decline of 50-75 mg/dL/hour 1, 2

Ongoing Management

When Glucose Reaches 250 mg/dL

Critical pitfall to avoid: Do NOT stop insulin when glucose normalizes—ketoacidosis takes much longer to resolve than hyperglycemia. 2, 3, 5

• Switch IV fluids to 5% dextrose with 0.45-0.75% saline while continuing insulin infusion at same rate. 1, 2, 3
• This prevents hypoglycemia while allowing insulin to continue clearing ketones. 2, 3, 5
• Target glucose 150-200 mg/dL until DKA fully resolves. 2

Monitoring Frequency

Check every 2-4 hours: 1, 2, 3

• Blood glucose
• Serum electrolytes (especially potassium)
• Venous pH
• Anion gap
• β-hydroxybutyrate (preferred over urine ketones)

Venous pH is adequate for monitoring after initial diagnosis—no need for repeated arterial sticks. 2, 3

Potassium Management Throughout Treatment

• Maintain serum K+ between 4-5 mEq/L throughout treatment. 2, 3
• Total body potassium depletion averages 3-5 mEq/kg despite normal or elevated initial levels. 2
• Inadequate potassium monitoring and replacement is a leading cause of mortality in DKA. 2

DKA Resolution Criteria

ALL of the following must be met: 1, 2, 3

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Transition to Subcutaneous Insulin

Once DKA is completely resolved AND patient can tolerate oral intake:

1. Administer basal insulin (glargine or detemir) subcutaneously 2-4 hours BEFORE stopping IV insulin infusion. 1, 2, 3

   • This overlap is essential to prevent rebound hyperglycemia and DKA recurrence. 1, 2
   • Stopping IV insulin without prior basal insulin is the most common error leading to DKA recurrence. 1, 2

2. Continue IV insulin for 1-2 hours after subcutaneous insulin is given. 1, 2

3. Start multiple-dose regimen with combination of rapid-acting and long-acting insulin. 1, 2

Special Considerations

Bicarbonate Administration

Bicarbonate is NOT recommended for pH >6.9-7.0 (which includes your patient with pH 7.29). 2

• Multiple studies show no benefit in resolution time or outcomes. 2
• May worsen ketosis, cause hypokalemia, and increase cerebral edema risk. 2

Identify and Treat Precipitating Factors

Obtain bacterial cultures (urine, blood, throat) if infection suspected and administer appropriate antibiotics. 1, 2

Consider other triggers: 2

• Infection (most common)
• Insulin omission or inadequacy
• Myocardial infarction
• Stroke
• Pancreatitis
• New-onset diabetes

Monitoring for Complications

• Watch for cerebral edema signs: altered mental status, headache, neurological deterioration (more common in children but can occur in adults). 2
• Monitor for hypokalemia-related complications: cardiac arrhythmias, respiratory muscle weakness. 1, 2, 4
• Avoid hypoglycemia by adding dextrose when glucose reaches 250 mg/dL. 2, 3, 4

Common Pitfalls to Avoid

1. Starting insulin before confirming K+ ≥3.3 mEq/L—can cause fatal arrhythmias. 1, 2
2. Stopping IV insulin when glucose normalizes—ketoacidosis persists longer than hyperglycemia. 2, 3, 5
3. Failing to add dextrose when glucose falls below 250 mg/dL—leads to hypoglycemia or premature insulin cessation. 2, 3
4. Discontinuing IV insulin without prior basal insulin administration—causes DKA recurrence. 1, 2
5. Inadequate potassium monitoring and replacement—leading cause of mortality. 2, 5
6. Relying on urine ketones for monitoring—nitroprusside method doesn't measure β-hydroxybutyrate and can falsely suggest worsening. 2, 3