Clinical CommunicationsHyponatremia and seizures in an ultradistance triathlete
Introduction
The increasing reports of hyponatremia associated with ultradistance sports over the past 15 years have paralleled the growth in participation in such events 1, 2, 3, 4. Hyponatremia is now recognized as one of the major medical risks of races such as ultradistance triathlons 1, 2, 3, 4, 5. Debate still exists about its pathogenesis and therefore possible methods of prevention and treatment 2, 4, 5, 6, 7. This case is presented to highlight issues around the etiology, presentation, and treatment of this potentially life-threatening disorder.
Section snippets
Case report
A 35-year-old male competitor collapsed having generalized seizures soon after completing an Ironman ultradistance triathlon (3.8-km swim, 180-km cycle, and 42.2-km run). The triathlon had taken him 14 h and 3 min to complete. He previously had been in good health, was taking no medications, and had completed two Ironman triathlons without requiring medical attention.
He had been weighed at registration 2 days before the race and again immediately on finishing, using calibrated Seca scales
Discussion
The subject of this paper suffered severe exercise-associated hyponatremia but survived intact with prompt and appropriate medical care. Many other competitors in the same race were hyponatremic (serum sodium concentrations between 119 to 134 mmol/L) and must be assumed to have been at risk of similar complications, although mild degrees of hyponatremia may be asymptomatic (4). Our work and the work of others suggest that hyponatremia is not unique to this event although it is less common in
Acknowledgements
We gratefully acknowledge the support of the Tom Anderson Memorial Trust.
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