Differential Diagnosis for Anion Gap Metabolic Acidosis
Single Most Likely Diagnosis
- Lactic Acidosis: This is often the most common cause of anion gap metabolic acidosis, particularly in critically ill patients or those with tissue hypoxia. It can result from various conditions such as sepsis, shock, or severe hypoxemia.
Other Likely Diagnoses
- Diabetic Ketoacidosis (DKA): A common cause of anion gap metabolic acidosis, especially in patients with diabetes mellitus. It is characterized by hyperglycemia, metabolic acidosis, and the presence of ketones.
- Alcoholic Ketoacidosis: Similar to DKA but occurs in the context of alcohol abuse. It is crucial to differentiate between the two as management strategies may vary.
- Renal Failure: As kidney function declines, the ability to excrete acids is impaired, leading to a buildup of acidic substances and an increase in the anion gap.
Do Not Miss Diagnoses
- Methanol or Ethylene Glycol Poisoning: Although less common, these conditions can be fatal if not promptly recognized and treated. They can cause anion gap metabolic acidosis along with other specific symptoms and signs.
- Salicylate Toxicity: Aspirin overdose can lead to anion gap metabolic acidosis. It's critical to consider this diagnosis, especially in patients with a history of overdose or suicidal attempts.
- Uremia: In advanced kidney disease, the accumulation of uremic toxins can lead to severe metabolic acidosis.
Rare Diagnoses
- Ketosis due to Starvation: Prolonged fasting or starvation can lead to ketosis and anion gap metabolic acidosis, though this is less common in clinical practice.
- Inborn Errors of Metabolism: Certain genetic disorders can result in the accumulation of organic acids, leading to anion gap metabolic acidosis. These are more commonly seen in pediatric patients.
- Pyroglutamic Acidemia (5-Oxoprolinuria): A rare condition caused by an inborn error of glutathione metabolism, leading to an accumulation of 5-oxoproline and resulting in anion gap metabolic acidosis.