Treatment of Diabetic Ketoacidosis (DKA)
The treatment of diabetic ketoacidosis requires aggressive fluid resuscitation with isotonic saline (15-20 ml/kg/hour initially), continuous intravenous insulin infusion without an initial bolus (0.1 units/kg/hour), and careful electrolyte management, particularly potassium replacement when serum K+ falls below 5.5 mEq/L. 1
Diagnostic Criteria and Severity Classification
DKA is diagnosed based on:
- Blood glucose >250 mg/dL (though euglycemic DKA can occur)
- Arterial pH <7.3
- Bicarbonate <15 mEq/L
- Moderate ketonemia or ketonuria 1
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 |
DKA is considered resolved when glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, and venous pH >7.3 1.
Treatment Algorithm
1. Fluid Therapy
- Initial fluid resuscitation: Isotonic saline at 15-20 ml/kg/hour for the first hour 1
- Subsequent fluid therapy: 0.45% saline at 4-14 ml/kg/hour based on corrected sodium levels 1
- Balanced crystalloid solutions are preferred over normal saline for maintenance fluid therapy 1
- Calculate corrected sodium: Measured sodium + 1.6 × [(glucose mg/dl - 100)/100] 1
2. Insulin Therapy
- Continuous IV insulin infusion at 0.1 units/kg/hour without an initial bolus 1
- For patients with complicated DKA (chronic kidney disease and heart failure), start at a reduced rate of 0.05 units/kg/hour 1
- Target glucose reduction rate: 50-70 mg/dL/hour 1
- Add dextrose to IV fluids when blood glucose falls to 250 mg/dL to prevent hypoglycemia while continuing insulin to clear ketones 2
- For uncomplicated DKA, subcutaneous rapid-acting insulin analogs may be used in emergency departments or step-down units 1
3. Electrolyte Management
- Potassium: Begin replacement when serum K+ <5.5 mEq/L, adding 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄) 1
- Phosphate: Include in replacement as KPO₄, especially with severe hypophosphatemia 1
- Bicarbonate: The FDA label indicates bicarbonate therapy is indicated in severe metabolic acidosis including diabetic acidosis, particularly when rapid increase in plasma total CO₂ content is crucial 3. However, this is not emphasized in current guidelines and should be reserved for severe cases.
Monitoring Protocol
- Hourly monitoring: vital signs, neurological status, blood glucose, fluid input/output 1
- Every 2-4 hours: electrolytes, BUN, creatinine, venous pH 1
- Watch for complications: cerebral edema, hypoglycemia, hypokalemia, fluid overload 1
Important Considerations and Pitfalls
Avoid Initial Insulin Bolus
Recent evidence shows that an insulin bolus prior to continuous infusion is associated with significantly more adverse effects (particularly hypokalemia) without corresponding benefits in DKA resolution time 4. The American Diabetes Association now recommends continuous IV insulin infusion without an initial bolus to avoid rapid glucose reduction and cerebral edema 1.
Potassium Management
Failure to recognize total-body potassium depletion and begin replacement despite initially normal serum potassium levels may lead to fatal cardiac arrhythmias 2. As insulin therapy drives potassium into cells, serum levels can drop rapidly, requiring close monitoring and proactive replacement.
Cerebral Edema Prevention
- Avoid too rapid correction of serum osmolality (not exceeding 3 mOsm/kg/h) 1
- In pediatric patients, limit initial vascular expansion to 50 ml/kg in the first 4 hours 1
- Cerebral edema is rare but potentially fatal, especially in children (0.7-1.0%) 1
Continue Insulin Until Ketoacidosis Resolves
Insulin treatment should be continued until the anion gap normalizes, not just until blood glucose normalizes 2. Failure to do so may result in inadequate reversal of ketogenesis.
Identify and Treat Precipitating Causes
Common precipitating factors include:
Failure to identify and treat these underlying causes may result in increased morbidity, mortality, or rapid relapse of ketoacidosis 2.