Diagnostic Considerations
It can be difficult at presentation to distinguish between ethanol, methanol, and ethylene glycol toxicity in an alcoholic patient with a high–anion gap metabolic acidosis and an osmolal gap. Additional possibilities, which may be concurrent abnormalities, include lactic acidosis and diabetic ketoacidosis. Thus, the diagnostic evaluation should include a careful history, an assessment for ketonemia or ketonuria, a urinalysis (eg, an evaluation for calcium oxalate crystals), and a measurement of serum levels of suspected toxins.
Isopropyl alcohol ingestion differs from AKA because it leads to ketosis without acidosis. This occurs because isopropyl alcohol is metabolized to acetone (a ketone but not a carboxylic acid, unlike acetoacetate).
The AKA differential diagnosis includes all metabolic conditions that can cause an increased–anion gap metabolic acidosis in a person who abuses ethanol. Salicylate intoxication and metabolic alkalosis (associated with vomiting and volume contraction) must be considered. If the plasma glucose level is elevated above 300 mg/dL upon presentation, consider diabetic ketoacidosis. [11, 20, 21, 22]
Because AKA is often precipitated by another medical illness, the diagnostic evaluation should include a search for potential precipitating factors when not clearly identified by history. Other disorders that may be seen in patients with AKA include the following:
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Liver dysfunction
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Hypoglycemia
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Heart failure
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Systemic infection
Differential Diagnoses
