What are the criteria for Diabetic Ketoacidosis (DKA)?

Diagnostic Criteria for Diabetic Ketoacidosis (DKA)

The diagnostic criteria for DKA include blood glucose >250 mg/dL, venous pH <7.3, serum bicarbonate <18 mEq/L, and moderate ketonuria or ketonemia. 1

Key Diagnostic Components

DKA is characterized by three main metabolic abnormalities:

1. Hyperglycemia:

   • Blood glucose >250 mg/dL 2, 1
   • Note: Euglycemic DKA can occur with glucose <200 mg/dL, particularly with SGLT2 inhibitor use 3

2. Metabolic Acidosis:

   • Venous pH <7.3 2, 1
   • Serum bicarbonate <18 mEq/L 2, 1
   • Elevated anion gap >10-12 mEq/L 1

3. Ketosis:

   • Moderate to high ketone levels in blood or urine 2, 1
   • Beta-hydroxybutyrate (β-OHB) measurement in blood is preferred over nitroprusside method 2

Laboratory Evaluation

The initial laboratory workup for suspected DKA should include:

• Plasma glucose
• Venous blood gases (pH)
• Serum electrolytes with calculated anion gap
• Serum ketones (preferably β-OHB)
• Blood urea nitrogen/creatinine
• Urinalysis with urine ketones
• Complete blood count with differential
• Electrocardiogram 1

Severity Classification

DKA can be classified based on severity:

Parameter	Mild	Moderate	Severe
Arterial pH	7.25-7.30	7.00-7.24	<7.00
Serum bicarbonate (mEq/L)	15-18	10-14	<10
Mental status	Alert	Alert/drowsy	Stupor/coma

Clinical Presentation

Common symptoms and signs of DKA include:

• Polyuria and polydipsia (98%)
• Weight loss (81%)
• Fatigue (62%)
• Dyspnea (57%)
• Vomiting (46%)
• Abdominal pain (32%)
• Kussmaul breathing (deep, rapid breathing)
• Fruity breath odor (acetone) 1, 4

Monitoring During Treatment

For monitoring resolution of DKA:

• Blood glucose should be checked every 1-2 hours
• Electrolytes, BUN, creatinine every 2-4 hours
• Venous pH to monitor resolution of acidosis
• Direct measurement of β-OHB is preferred for monitoring ketosis resolution 2, 1

Criteria for Resolution of DKA

DKA is considered resolved when:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH ≥7.3 2

Important Considerations

1. Euglycemic DKA: Can occur with blood glucose <200 mg/dL, particularly with SGLT2 inhibitor use, pregnancy, decreased caloric intake, alcohol consumption, or recent insulin use 3

2. Monitoring Ketones: The nitroprusside method only measures acetoacetic acid and acetone, not β-OHB (the predominant ketone in DKA). During treatment, β-OHB converts to acetoacetic acid, which can falsely suggest worsening ketosis 2

3. Potassium Monitoring: Critical to monitor potassium before and during insulin therapy, as insulin drives potassium into cells and can precipitate hypokalemia 5

4. Bicarbonate Therapy: Generally not recommended except in cases where arterial pH <6.9 in adults 1

5. Precipitating Factors: Always identify and treat underlying causes (infection, insulin omission, myocardial infarction, etc.) 4, 6

By promptly recognizing these diagnostic criteria and initiating appropriate treatment, mortality from DKA can be significantly reduced.