Diabetic Ketoacidosis (DKA) Workup and Management
The management of DKA requires immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour initially, followed by insulin therapy at 0.1 U/kg/hour intravenously after 1-2 hours of fluid replacement, with careful monitoring of electrolytes and glucose levels. 1
Diagnostic Criteria and Initial Workup
DKA is diagnosed when the following criteria are met:
- Blood glucose >250 mg/dL
- pH <7.3 or bicarbonate <15 mEq/L
- Presence of ketones in blood or urine 1
Essential Laboratory Tests:
- Plasma glucose
- Blood urea nitrogen/creatinine
- Serum ketones (β-hydroxybutyrate has high sensitivity at 98% with cutoff of 1.5 mmol/L)
- Electrolytes (sodium, potassium, chloride)
- Serum osmolality
- Arterial blood gases
- Complete blood count
- Urinalysis 1
Management Algorithm
1. Fluid Resuscitation
- First Hour: Isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour to address dehydration and hypotension
- This step is crucial before insulin administration to improve tissue perfusion and renal function 1
2. Insulin Therapy
- Begin 1-2 hours after starting fluid replacement
- Continuous IV insulin infusion at 0.1 U/kg/hour (5-7 U/hour in adults)
- Target glucose decline: 50-75 mg/dL per hour
- If glucose doesn't decrease by at least 50 mg/dL in first hour:
- Check hydration status
- If adequate, double insulin infusion rate hourly until achieving stable decline 1
3. Glucose Management
- When glucose reaches 250 mg/dL:
- Reduce insulin to 0.05-0.1 U/kg/hour
- Add dextrose (5-10%) to IV fluids
- This prevents too rapid decline in glucose which can lead to cerebral edema 1
4. Electrolyte Replacement
- Potassium: Begin when serum K+ <5.5 mEq/L and adequate urine output confirmed
- Add 20-30 mEq potassium (2/3 KCl and 1/3 KPO₄) per liter of IV fluid 1
- Phosphate: Consider replacement if:
- Serum phosphate <1.0 mg/dL
- Patient has cardiac dysfunction, anemia, or respiratory depression 1
- Bicarbonate: Generally not indicated if pH >7.0
5. Monitoring
- Blood glucose: Every 1-2 hours until stable
- Electrolytes, BUN, creatinine: Every 2-4 hours
- Venous pH and anion gap: To evaluate resolution of acidosis 1
Resolution Criteria and Transition to Subcutaneous Insulin
DKA is considered resolved when:
- Glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH >7.3
- Anion gap normalized 1
Transition Protocol:
- Start subcutaneous insulin
- Continue IV insulin for 1-2 hours after first subcutaneous dose
- For Type 1 diabetes: Continue with multiple dose insulin therapy or insulin pump
- For Type 2 diabetes: Consider metformin while continuing subcutaneous insulin 1
Complications to Monitor and Prevent
Cerebral Edema
- More common in children and adolescents
- Avoid rapid correction of hyperglycemia
- Maintain glucose decline rate between 50-75 mg/dL per hour 1, 2
Hypoglycemia
- Common adverse event during treatment
- Monitor glucose frequently
- Add dextrose to IV fluids when glucose approaches 250 mg/dL 1, 3
Hypokalemia
- Can develop during insulin therapy
- Monitor potassium levels closely
- Replace as needed when K+ <5.5 mEq/L 1
Special Considerations
Patients with Anemia
- Anemia worsens tissue hypoxia in acidotic states
- Consider lower threshold for ICU admission
- Monitor cardiac function closely as anemia increases cardiac workload
- Consider more conservative fluid management if cardiac compromise present 1
Patients with Cardiac Issues
Airway Management in Critical Cases
- For impending respiratory failure, intubation and mechanical ventilation are preferred over BiPAP due to aspiration risks
- Monitor acid-base status closely during intubation 2
Patient Education Before Discharge
Before discharge, provide education on:
- Recognition of DKA symptoms
- Sick day management
- Regular follow-up with healthcare providers
- Insulin regimen adjustments 1, 3
Remember that DKA is a medical emergency with potential mortality if not treated properly. Early recognition and prompt, systematic management are essential for optimal outcomes.