D-Lactic Acidosis

Abstract

d-Lactic acidosis, also referred to as d-lactate encephalopathy, is a rare neurologic syndrome that occurs in individuals with short bowel syndrome or following jejuno-ileal bypass surgery. Symptoms typically present after the ingestion of high-carbohydrate feedings. Neurologic symptoms include altered mental status, slurred speech, and ataxia, with patients often appearing drunk. Onset of neurologic symptoms is accompanied by metabolic acidosis and elevation of plasma d-lactate concentration. In these patients, malabsorbed carbohydrate is fermented by an abnormal bacterial flora in the colon, which produces excessive amounts of d-lactate. High amounts of d-lactate are absorbed into the circulation, resulting in an elevated concentration of d-lactate in the blood. Development of neurologic symptoms has been attributed to d-lactate, but it is unclear if this is the cause or whether other factors are responsible. This review examines the pathophysiology of the production and accumulation of d-lactate while exploring the potential factors contributing to the development of neurologic manifestations. Methods of diagnosis and treatment are reviewed. Areas requiring further investigation are identified.