Metabolic Acidosis.

Metabolic acidosis is a common disorder that occurs in a variety of clinical settings. The kidney maintains acid-base homeostasis through the elimination of protons and reabsorption/generation of bicarbonate. Metabolic acidosis develops when these mechanisms are overwhelmed or impaired, in situations such as rapid production of nonvolatile acids, abnormally high bicarbonate losses, and impaired acid excretion by the kidney. Determining the presence or absence of an anion gap is the first step in ascertaining the etiology of metabolic acidosis. The presence or absence of an osmolal gap, urine pH, and serum potassium levels may be useful in certain settings. We discuss a comprehensive approach to metabolic acidosis and present important clinical scenarios.