Selected Topics: Sports MedicineLarge-Volume Hypertonic Saline Therapy in Endurance Athlete with Exercise-Associated Hyponatremic Encephalopathy

BackgroundSmall-volume boluses of intravenous hypertonic saline are the recommended therapy for exercise-associated hyponatremic encephalopathy (EAHE). Failure to properly diagnose and treat EAHE has been associated with significant morbidity and death. To prevent this, current consensus statement guidelines recommend up to three 100-mL boluses of 3% NaCl spaced at 10-min intervals to correct symptoms. Due to lack of evidence, however, guidelines are vague regarding the maximal volume that can be safely administered in a given time period beyond these initial boluses.ObjectivesThis case report will review the underlying pathophysiology, clinical presentation, diagnosis, and management of EAHE in a patient refractory to initial treatment.Case ReportWe report a case of EAHE in an experienced marathon runner requiring large-volume infusion (950 mL) of 3% NaCl therapy for resolution of symptoms without any adverse events.ConclusionAlthough further research is needed, this case may provide helpful information for acute care and sports medicine physicians who encounter patients with EAHE refractory to initial therapy.