Recommended Labs and Initial Treatment for Diabetic Ketoacidosis (DKA)
The diagnosis and initial treatment of DKA requires specific laboratory tests including blood glucose >250 mg/dL, arterial pH <7.3, bicarbonate <15 mEq/L, and moderate ketonemia or ketonuria, followed by immediate fluid resuscitation with isotonic saline at 15-20 ml/kg/hour and continuous IV insulin infusion at 0.1 units/kg/hour without an initial bolus. 1
Diagnostic Laboratory Tests for DKA
Essential Initial Labs:
- Blood glucose (typically >250 mg/dL, though euglycemic DKA can occur) 1, 2, 3
- Arterial or venous pH (<7.3 indicates DKA) 1
- Serum bicarbonate (<15 mEq/L) 1
- Serum ketones (preferred) or urine ketones 1, 2
- Anion gap calculation (elevated >10 mEq/L) 2
- Electrolytes (sodium, potassium, chloride) 1, 2
- Blood urea nitrogen (BUN) and creatinine 1, 2
- Complete blood count with differential 1, 2
- A1C (to assess long-term glycemic control) 1, 2
- Urinalysis 1, 2
- Electrocardiogram (to assess for cardiac abnormalities and effects of electrolyte disturbances) 1, 2
Additional Labs to Consider:
- Phosphate level 1
- Osmolality and osmolar gap calculation 4
- Amylase and lipase (to rule out pancreatitis) 2
- Hepatic transaminases 2
- Troponin and creatine kinase (if cardiac involvement suspected) 2
- Blood and urine cultures (if infection suspected) 2
- Chest radiography (if respiratory symptoms present) 2
DKA Severity Classification
DKA severity can be classified based on the following parameters:
| Parameter | Mild | Moderate | Severe |
|---|---|---|---|
| Arterial pH | 7.25-7.30 | 7.00-7.24 | <7.00 |
| Bicarbonate (mEq/L) | 15-18 | 10-14 | <10 |
| Mental Status | Alert | Alert/drowsy | Stupor/coma |
Initial Treatment Protocol
1. Fluid Therapy
- Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hour for the first hour 1
- After the first hour, switch to 0.45% saline at 4-14 ml/kg/hour based on corrected sodium levels 1
- Calculate corrected sodium using: Measured sodium + 1.6 × [(glucose mg/dl - 100)/100] 1
- Balanced crystalloid solutions are preferred over normal saline for maintenance fluid therapy 1
2. Insulin Therapy
- Start continuous IV insulin infusion at 0.1 units/kg/hour without an initial bolus 1, 5
- For patients with complications like chronic kidney disease or heart failure, consider a reduced rate of 0.05 units/kg/hour 1
- Target glucose reduction rate of 50-70 mg/dL/hour 1
- For uncomplicated DKA in appropriate settings, subcutaneous rapid-acting insulin analogs may be used 1
3. Electrolyte Management
- Monitor potassium closely and begin replacement when serum K+ <5.5 mEq/L 1
- Add 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄) 1
- Include phosphate replacement as KPO₄, especially with severe hypophosphatemia 1
Monitoring During Treatment
Hourly Monitoring:
- Vital signs
- Neurological status
- Blood glucose
- Fluid input/output 1
Every 2-4 Hours:
- Electrolytes
- BUN and creatinine
- Venous pH 1
Potential Complications to Watch For
- Cerebral edema (rare but potentially fatal, especially in children) 1, 5
- Hypoglycemia (monitor for symptoms including sweating, drowsiness, dizziness) 5
- Hypokalemia (can lead to cardiac arrhythmias) 1
- Fluid overload (especially in patients with heart or kidney disease) 1, 5
Resolution Criteria
DKA is considered resolved when:
- Glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH >7.3 1
Important Considerations
- Euglycemic DKA can occur, especially with SGLT2 inhibitor use, so don't rule out DKA based solely on normal blood glucose 2, 3
- Always identify and treat the underlying precipitating factor (infection, missed insulin, new diagnosis) 1, 2
- Continuous monitoring is essential as rapid correction of osmolality can lead to cerebral edema 1
- Patient education on diabetes management, including self-monitoring and sick-day protocols, should be provided before discharge 1