Review of Clinical Disorders Causing Metabolic Acidosis

The various mechanisms responsible for the development of metabolic acidosis are briefly reviewed, and the metabolic acidoses are categorized both by mechanism and by the presence or absence of an increased anion gap. When a diagnosis of metabolic acidosis is established, it becomes imperative to identify the primary causative etiology as quickly as possible. This is often readily apparent from the history and physical exam (ie, diabetic ketoacidosis when the glucose is very high in a patient with diabetes mellitus; lactic acidosis in a patient with sepsis and hypotension, etc.). However, when the etiology is not obvious, it is very helpful to determine if the metabolic acidosis is of the hyperchloremic or high-anion-gap type (or a combination of both). Once this categorization has been established, a stepwise consideration of each of the potential causative etiologies will usually direct the clinician to order the appropriate diagnostic studies.