Differential Diagnosis for High Anion Gap Metabolic Acidosis
Single Most Likely Diagnosis
- Lactic Acidosis: This is often the most common cause of high anion gap metabolic acidosis, particularly in critically ill patients. It can result from tissue hypoxia, sepsis, or biguanide (metformin) toxicity, leading to increased lactate production.
Other Likely Diagnoses
- Diabetic Ketoacidosis (DKA): A common cause of high anion gap metabolic acidosis, characterized by hyperglycemia, ketosis, and metabolic acidosis, often seen in patients with diabetes mellitus.
- Alcoholic Ketoacidosis: Similar to DKA but occurs in the context of alcohol abuse, with ketosis and metabolic acidosis.
- Renal Failure: Acute or chronic kidney disease can lead to the accumulation of organic acids, resulting in high anion gap metabolic acidosis.
- Salicylate Toxicity: Aspirin overdose can cause a high anion gap metabolic acidosis due to the accumulation of salicylate and its metabolites.
Do Not Miss Diagnoses
- Methanol or Ethylene Glycol Poisoning: Although less common, these conditions can be fatal if not promptly recognized and treated. They cause high anion gap metabolic acidosis through the accumulation of toxic metabolites.
- Carbon Monoxide Poisoning: Can lead to lactic acidosis and high anion gap metabolic acidosis due to tissue hypoxia.
Rare Diagnoses
- Ketosis due to Starvation: Prolonged fasting or starvation can lead to ketosis and high anion gap metabolic acidosis.
- Inborn Errors of Metabolism: Certain genetic disorders, such as methylmalonic acidemia or propionic acidemia, can cause high anion gap metabolic acidosis, especially in pediatric patients.
- Pyroglutamic Acidemia (5-Oxoprolinuria): A rare condition caused by an inborn error of glutathione metabolism, leading to the accumulation of 5-oxoproline and high anion gap metabolic acidosis.
- Isovaleric Acidemia: Another inborn error of metabolism that can result in high anion gap metabolic acidosis due to the accumulation of isovaleric acid.