Exercise-associated hyponatraemia on the Kokoda Trail.

OBJECTIVE: The objective of the present study was to determine the prevalence of exercise-associated hyponatraemia in hikers/trekkers along the Kokoda Trail. METHODS: This was a cross-sectional study of 191 trekkers on the Kokoda Trail, Papua New Guinea. Blood was taken and analysed immediately using point-of-care technology 2 days walk from each end of the Trail. RESULTS: The main outcome measure was hyponatraemia defined as serum sodium level less than 135 mmol/L. Three participants (1.6%, 95% CI 0.5-4.5%) were found to have mild hyponatraemia. The hyponatraemic group had a median estimated fluid intake on the day of testing that was almost double that of the normal sodium group (6 L vs 3.3 L). CONCLUSION: Exercise-associated hyponatraemia occurs in trekkers on the Kokoda Trail. Strategies for prevention of exercise-associated hyponatraemia should be delivered to trekkers via the trekking companies, chiefly focussing on only drinking in response to thirst.

Severe exercise-associated hyponatremia on the Kokoda Trail, Papua New Guinea.

Exercise-associated hyponatremia is the most common medical complication of ultradistance exercise and is usually caused by excessive hypotonic fluid intake. We report a case of severe hyponatremia in a healthy male trekking the Kokoda Trail in the remote Southern Highlands of Papua New Guinea. A 43-year-old male collapsed and had a generalized seizure in the afternoon of the third day of a guided trek. He was evacuated the following morning and was found to have a serum sodium level of 107 mmol/L on arrival to hospital. The case highlights that a high index of suspicion is required to identify patients with exercise-associated hyponatremia. Early diagnosis and appropriate management is critical to avoid the potentially fatal consequences of severe hyponatremia. The diagnosis and treatment of exercise-associated hyponatremia is particularly challenging in the remote Papua New Guinea jungle. Education of trek leaders, medics, and trekkers in appropriate preventative measures and the rapid treatment of exercise-associated hyponatremia is essential to avoid recurrences of this life-threatening condition.