Exercise associated hyponatraemia leading to tonic-clonic seizure

Abstract

A 34-year-old Filipino lady presented to the emergency department with breathlessness and muscle cramping following a Bikram yoga workout. The patient reported sweating excessively while performing 90 min of strenuous exertion in a humidified room heated to an ambient temperature of 40.6°C. After the workout she drank 3.5 litres of water before experiencing breathlessness, severe muscle cramps, nausea and general malaise. Initial investigations revealed severe hyponatraemia (120 mmol/l). Despite early sodium replacement the patient dropped her Glasgow coma scale to 9/15 and developed tonic clonic seizures, requiring intubation and admission to the intensive care unit. The hyponatraemia was slowly corrected on the intensive care unit and the patient made a full recovery over the course of 5 days. This case highlights the dangers of overzealous fluid replacement following severe exertion in a hot environment.

Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015

“…In addition, EAH has been reported in US professional and college American rules football players,40 41 and has led to the deaths of three US high school football players between 2008 and 2014 63 64 69. Symptomatic hyponatraemia has also been reported in a 48-year-old lawn bowler who was heterozygous for the Delta F508 CF mutation, although it is unclear if complete genetic analysis for all possible CF mutations was performed,81 as well as in a 34-year-old woman following a Bikram Yoga session82 and in a 39-year-old woman following a 2 h workout including tennis and weightlifting 83. Cases of symptomatic EAH have also been induced in two separate laboratory studies involving low-intensity exercise conducted in high ambient temperatures 84 85.…”

“…However, experimental114 115 and observational116 117 studies speculate that EAMC may reflect neurological changes due to fatigue rather than uncompensated water and sodium losses incurred during exercise in some cases. Muscle cramping and tremor have also been associated with overdrinking and hyponatraemia in athletes,82 100 118 119 clinical populations120 and animals 121…”

“…On departure from the event site, athletes with asymptomatic EAH should be advised to seek urgent medical attention if any neurological signs or symptoms of EAH develop within 24 h after event completion, since delayed-onset symptomatic EAH may frequently occur 40 42 46 52 72 80 82 91 100 122 156. Ideally, an athlete with asymptomatic EAH should have a companion on discharge from the medical area to observe the affected athlete for signs and symptoms of evolving EAH, since the neurological impairments associated with EAH may limit the athlete's ability to accurately self-assess his or her own status.…”

“…Acute severely symptomatic hyponatraemia is a rapidly progressing, life-threatening emergency that requires immediate administration of intravenous HTS (such as 3% sodium chloride) 38 42 49 51 72 82 91. Because EAH is an acute rather than chronic process, athletes presenting with symptomatic hyponatraemia can and should be treated with HTS as there is no risk of osmotic demyelination after exposure to HTS, but there is grave risk of brain herniation and non-cardiogenic pulmonary oedema if HTS is not administered 5 6 38 47 50 62…”

Hiker Fatality From Severe Hyponatremia in Grand Canyon National Park

“…We share this case because proper initial management of EAH can be critical to the outcome, and there is evidence that current treatment guidelines for EAH have yet to be universally adopted. 9,13,[15][16][17][18][19][20][21][22][23][24] Case presentation On September 3, 2008, a previously healthy 47-year-old woman from London, England, hiked for approximately 10 km on the South Kaibab Trail in Grand Canyon National Park, descending and then ascending roughly 900 m in elevation over a 5-hour period. The day was clear and sunny.…”