Three cases of severe hyponatremia during a river run in Grand Canyon National Park.
We present 3 cases of severe hyponatremia occurring on a commercially guided river rafting trip on the Colorado River in Grand Canyon National Park. All 3 women appeared to have been overhydrating because of concern about dehydration and required evacuation within 24 hours of each other after the staggered onset of symptoms, which included fatigue and emesis progressing to disorientation or seizure. Each was initially transferred to the nearest hospital and ultimately required intensive care. Imaging and laboratory data indicated all 3 patients had hypervolemic hyponatremia. Unlike the well-documented exercise-associated hyponatremia cases commonly occurring in prolonged endurance athletic events, these 3 unique cases of acute hyponatremia were not associated with significant exercise. The cases illustrate the diagnostic and treatment challenges related to acute hyponatremia in an austere setting, and underscore the importance of preventive measures focused on avoidance of overhydration out of concern for dehydration.
Grand Canyon National Park, Preventive Search and Rescue Team, Branch of Emergency Services, Grand Canyon, AZ (Ms Pearce and Dr Myers).
Emily A
EA
Pearce
Grand Canyon National Park, Preventive Search and Rescue Team, Branch of Emergency Services, Grand Canyon, AZ (Ms Pearce and Dr Myers).
Thomas M
TM
Myers
Department of Physical Medicine and Rehabilitation, Department of Veterans Affairs, Northern California Health Care System, and University of California Davis Medical Center, Sacramento, CA (Dr Hoffman). Electronic address: mdhoffman@ucdavis.edu.
Martin D
MD
Hoffman
D000368:Aged; D004326:Drinking; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000209:etiology* / Q000473:pathology; D000068316:Parks, Recreational; D045483:Rivers; D014867:Water / Q000008:administration & dosage / Q000009:adverse effects*
D014867:Water
arginine vasopressin; exercise; exercise-associated hyponatremia; hypertonic saline; hyponatremia; sodium; syndrome of inappropriate ADH secretion; water-electrolyte imbalance