Initial Management of Diabetic Ketoacidosis (DKA)
The initial management of diabetic ketoacidosis (DKA) requires immediate fluid resuscitation with balanced crystalloid solutions at 15-20 ml/kg/hour for the first hour, followed by continuous intravenous insulin therapy at 0.1 units/kg/hour without an initial bolus, and careful electrolyte monitoring and replacement. 1
Diagnosis and Assessment
DKA is diagnosed based on the following criteria:
- Blood glucose >250 mg/dL (though euglycemic DKA can occur)
- Arterial pH <7.3
- Bicarbonate <15 mEq/L
- Moderate ketonemia or ketonuria 1, 2
Severity classification:
| 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 workup should include:
- Electrolytes, phosphate, BUN, creatinine
- Urinalysis
- Complete blood count with differential
- A1C
- ECG 2
Step-by-Step Management Algorithm
1. Fluid Resuscitation
- First line: Balanced crystalloid solutions at 15-20 ml/kg/hour for the first hour 1, 3
- After first hour: Switch to 0.45% saline at 4-14 ml/kg/hour based on corrected sodium levels 1
- Special consideration: For patients with CKD and heart failure, reduce rate to 5-10 ml/kg/hour for the first hour 1
- Goal: Modest positive fluid balance of 1-2L by the end of treatment 1
Recent evidence shows balanced fluids are associated with faster DKA resolution compared to normal saline (13 hours vs 17 hours) 3
2. Insulin Therapy
- Standard approach: Continuous IV insulin at 0.1 units/kg/hour without an initial bolus 1
- For CKD/heart failure patients: Reduced rate of 0.05 units/kg/hour 1
- Target: Glucose reduction rate of 50-70 mg/dL/hour 1
- Alternative: For uncomplicated DKA, subcutaneous rapid-acting insulin analogs may be used in emergency departments 1
3. Electrolyte Management
- Potassium: Begin replacement when serum K+ <5.5 mEq/L and adequate urine output is confirmed
- Add 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄) 1
- Phosphate: Include as KPO₄, especially with severe hypophosphatemia 1
- Sodium: Monitor corrected sodium using formula: Measured sodium + 1.6 × [(glucose mg/dl - 100)/100] 1
4. Monitoring
- Hourly: Vital signs, neurological status, blood glucose, fluid input/output
- Every 2-4 hours: Electrolytes, BUN, creatinine, venous pH 1
- Cardiac monitoring: Consider cardiac enzyme monitoring as myocardial injury can occur in DKA 4
Complications to Watch For
Cerebral Edema
- Rare but potentially fatal (0.7-1.0% in children)
- Prevention: Avoid rapid correction of serum osmolality (not exceeding 3 mOsm/kg/h)
- In pediatric patients: Limit initial vascular expansion to 50 ml/kg in first 4 hours 1
Electrolyte Imbalances
- Hypokalemia occurs in approximately 50% of cases during treatment 1
- Hyperkalemia risk increases with dual RAAS blockade 1
Fluid Overload
- Monitor for signs of pulmonary edema
- Consider early use of diuretics if volume overload develops 1
Cardiac Complications
- Can be difficult to detect but potentially fatal
- Elevated cardiac enzymes and prolonged QT interval may occur 4
Resolution Criteria
DKA is considered resolved when:
- Glucose levels <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH >7.3 1
Common Pitfalls to Avoid
- Administering an insulin bolus: This can lead to rapid glucose reduction and increased risk of cerebral edema 1
- Using normal saline exclusively: Balanced crystalloids are preferred as they result in faster DKA resolution and lower risk of hyperchloremic metabolic acidosis 1, 3
- Neglecting to identify and treat underlying causes: Infection, missed insulin doses, or new-onset diabetes must be addressed 1
- Overlooking euglycemic DKA: Particularly in patients taking SGLT-2 inhibitors 2
- Inadequate monitoring: Failure to monitor electrolytes frequently can lead to missed complications 1