D‐Lactic Acidosis

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.