Diagnosis and Treatment of Diabetic Ketoacidosis (DKA)
The first step in managing DKA is to confirm diagnosis based on the triad of hyperglycemia (blood glucose >250 mg/dL), metabolic acidosis (arterial pH <7.30, serum bicarbonate <18 mEq/L), and presence of significant ketonemia/ketonuria, followed immediately by fluid resuscitation with isotonic saline. 1
Diagnostic Criteria for DKA
DKA is diagnosed when the following criteria are met:
- Plasma glucose >250 mg/dL (though euglycemic DKA can occur)
- Arterial pH <7.30
- Serum bicarbonate <18 mEq/L
- Presence of significant ketonemia and ketonuria
- Variable but typically elevated serum osmolality 1
Clinical presentation often includes:
- Fruity breath odor (acetone)
- Nausea, vomiting, abdominal pain
- Kussmaul breathing (deep, rapid breathing)
- Altered mental status
- Polyuria, polydipsia 1
Initial Management Algorithm
1. Fluid Resuscitation (First Priority)
- Begin with isotonic saline (0.9% NaCl) at 10-20 mL/kg/hour for the first hour
- Initial fluid reexpansion should not exceed 50 mL/kg over the first 4 hours to avoid cerebral edema risk
- After initial hour, continue rehydration by calculating fluid deficit to be replaced evenly over 48 hours using 0.9% NaCl at 1.5 times the 24-hour maintenance requirements 1
2. Insulin Therapy
- Begin 1-2 hours AFTER starting fluid resuscitation
- Use continuous IV insulin infusion at 0.1 units/kg/hour WITHOUT an initial bolus
- Target glucose reduction: 50-75 mg/dL per hour
- Only start insulin when K+ ≥3.3 mEq/L
- Add dextrose (D5W or D10W) when blood glucose reaches 250 mg/dL to prevent hypoglycemia while continuing insulin to clear ketones 1, 2
3. Potassium Replacement
- Start once renal function is confirmed and serum potassium is known
- Begin when serum K+ <5.5 mEq/L and adequate urine output is confirmed
- Use 20-40 mEq/L potassium (2/3 KCl or potassium-acetate and 1/3 KPO₄) added to IV fluids 1
Monitoring During Treatment
- Vital signs and neurological status: every 1-2 hours
- Blood glucose: hourly
- Electrolytes, venous pH, and anion gap: every 2-4 hours 1
Important Complications to Monitor
Hypoglycemia
- Most common adverse reaction of insulin therapy
- Can lead to unconsciousness, convulsions, and potential permanent brain damage
- Early warning symptoms include sweating, drowsiness, dizziness, anxiety, tremor, blurred vision, and hunger 2
Cerebral Edema
- Serious risk especially in pediatric patients
- Avoid excessive fluid administration in the first 4 hours 1
Hypokalemia
- Insulin drives potassium into cells, potentially causing dangerous hypokalemia
- Can lead to respiratory paralysis, ventricular arrhythmia, and death if untreated
- Careful potassium monitoring is essential 2
Identifying and Treating Precipitating Factors
Common precipitating factors include:
- Infection
- Omission of insulin doses
- New-onset diabetes
- Myocardial infarction
- Medications (e.g., steroids, SGLT2 inhibitors)
- Emotional stress 1, 3
Identifying and treating the underlying cause is crucial to prevent recurrence. Consider appropriate diagnostic tests such as:
- Blood and urine cultures if infection suspected
- Electrocardiography
- Chest radiography if indicated 3
Transition to Subcutaneous Insulin
Transition from IV to subcutaneous insulin only after:
- Resolution of acidosis (pH ≥7.3)
- Anion gap has normalized
- Patient is able to eat
- Blood glucose is stable 1, 4
Discharge Criteria
Patients can be discharged when:
- Blood glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH ≥7.3
- Normalized anion gap
- Ability to eat adequately
- Precipitating factor identified and treated
- Appropriate insulin regimen established
- Patient educated on diabetes management including sick day protocols 1
DKA is a medical emergency requiring prompt recognition and treatment. The cornerstone of management is aggressive fluid resuscitation followed by insulin therapy, with careful attention to electrolyte management and identification of precipitating factors.