From the Guidelines
The key lab values to assess for diabetic ketoacidosis (DKA) are blood glucose >250 mg/dl, venous pH <7.3, bicarbonate <15 mEq/l, and moderate ketonuria or ketonemia, as indicated by the most recent and highest quality study 1.
Diagnostic Criteria
The diagnostic criteria for DKA include:
- Blood glucose: >250 mg/dL
- Venous pH: <7.3
- Serum bicarbonate: <15 mEq/L
- Presence of ketones in urine or serum Additional important lab values to monitor:
- Anion gap: >10-12 mEq/L
- Serum potassium: Often elevated initially, but total body potassium is depleted
- Blood urea nitrogen (BUN) and creatinine: May be elevated due to dehydration
- Serum osmolality: Usually elevated
Monitoring and Treatment
Monitor these values frequently during treatment, typically every 2-4 hours, as recommended by 1. Correct glucose, electrolytes, and acid-base balance with IV fluids, insulin, and electrolyte replacement. The goal is to gradually normalize these values while avoiding complications like cerebral edema.
Rationale
These lab abnormalities occur due to insulin deficiency and increased counter-regulatory hormones, leading to hyperglycemia, ketone production, and metabolic acidosis, as explained in 1. Monitoring these values helps guide treatment and assess resolution of DKA.
Key Considerations
- Measurement of -OHB in the blood is the preferred method for monitoring DKA, as stated in 1.
- Assessments of urinary or serum ketone levels by the nitroprusside method should not be used as an indicator of response to therapy, as noted in 1.
- Criteria for resolution of DKA include a glucose <200 mg/dl, serum bicarbonate ≥18 mEq/l, and a venous pH of >7.3, as indicated in 1.
From the Research
Laboratory Values Indicative of Diabetic Ketoacidosis (DKA)
The laboratory values indicative of DKA include:
- Serum glucose level greater than 250 mg per dL 2, 3, 4
- pH less than 7.3 2, 4, 5
- Serum bicarbonate level less than 18 mEq per L 2, 3, 4
- Elevated serum ketone level 2, 3, 4, 6
- Anion gap greater than 10 mEq/L 4 or greater than 12 5
- Dehydration 2
- Electrolyte imbalances 2, 4
- Blood urea nitrogen and creatinine elevations 2, 4, 5
- Positive ketones in serum or urine 4
Specific Ketone Body Levels
Specific ketone body levels that may be indicative of DKA include:
- Beta-hydroxybutyrate level greater than 6.3 mmol/l 6
- Acetoacetate level greater than 1.4 mmol/l 6
- Total ketone body level greater than 8.0 mmol/l 6
Other Laboratory Tests
Other laboratory tests that may be useful in the diagnosis and management of DKA include: