Laboratory Abnormalities in Alcoholic Ketoacidosis
Alcoholic ketoacidosis presents with a characteristic pattern of metabolic acidosis with elevated anion gap and ketosis, but glucose levels are typically normal, low, or only mildly elevated (rarely >250 mg/dL), which distinguishes it from diabetic ketoacidosis. 1
Core Metabolic Abnormalities
Acid-Base Disturbances
- Metabolic acidosis with elevated anion gap is the hallmark finding, often profound in severity 2, 3
- Elevated β-hydroxybutyrate (β-OHB) is the predominant ketone body, with the ratio of β-OHB to acetoacetate typically elevated (can be 4:1 or higher) 4, 5
- Positive serum and urine ketones on testing 1, 2
- Low serum bicarbonate, though typically not as low as 18 mEq/L (unlike starvation ketosis which usually stays above this threshold) 1
- Decreased PaCO2 due to compensatory respiratory alkalosis 4
Glucose Abnormalities
- Normal to mildly elevated glucose (rarely exceeding 250 mg/dL), or frank hypoglycemia may be present 1, 6, 2
- This contrasts sharply with diabetic ketoacidosis where glucose is typically >250 mg/dL 6
Electrolyte Abnormalities
Multiple electrolyte disturbances are common and potentially life-threatening:
- Hypokalemia (34% of patients) 5
- Hyponatremia (46% of patients) 5
- Hypophosphatemia (41-42% of patients) - can cause severe neurological complications including disturbance of consciousness and polyradiculitis 5, 7
- Hypomagnesemia (42% of patients) 5, 7
- Hypocalcemia may also occur 7
Additional Laboratory Findings
Lactate Elevation
- Elevated lactate levels are frequently present and can be profoundly elevated (mean 8.5 mmol/L in some patients) 3, 5
- Some patients may have predominant lactic acidosis with only minor elevations in β-OHB, though both contribute to the anion gap 5
Other Abnormalities
- Low or absent blood alcohol level at presentation (despite history of heavy use) 7
- Elevated blood urea nitrogen/creatinine reflecting dehydration 2
Critical Clinical Pitfall
The nitroprusside reaction method (standard urine dipstick and serum ketone tests) only detects acetoacetate and acetone, NOT β-hydroxybutyrate, which is the predominant ketone in AKA. 6 This means standard ketone tests may underestimate the severity of ketosis. Point-of-care capillary β-OHB measurement devices provide more accurate assessment 5.
Associated Complications to Screen For
When evaluating laboratory abnormalities, also assess for common complications: