Metabolic acidosis, increased anion gap

Definition

Gap >12 meq

Etiology

Lactic acidosis
- Type A (tissue hypoxia): cardiogenic, septic, or hemorrhagic shock; seizure; carbon monoxide or cyanide poisoning
- Type B (nonhypoxic): hepatic or renal failure, intestinal ischemia, diabetes especially with metformin use, ketoacidosis, infection, leukemia or lymphoma, drugs (ethanol, methanol, salicylates, isoniazid), AIDS, idiopathic (usually in debilitated patients)
Diabetic ketoacidosis
Starvation ketoacidosis
Alcoholic ketoacidosis
- Frequently with mixed disorders (10% have triple acid-base disorder)
- Acid-base disorders in alcoholism include: three types of metabolic acidosis (ketoacidosis, lactic acidosis, or hyperchloremic acidosis from bicarbonate loss in urine from ketonuria); metabolic alkalosis from volume contraction and vomiting; respiratory alkalosis from alcohol withdrawal, pain, sepsis, or liver disease
Uremic acidosis (usually at GFR <20 mL/min)
Ethylene glycol toxicity
Methanol toxicity
Salicylate toxicity (mixed metabolic acidosis with respiratory alkalosis)
Other: paraldehyde, isoniazid, iron, rhabdomyolysis

See related DDx

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