Prevalence of hyponatremia in acute medical admissions in tropical Asia Pacific Australia

ObjectiveTo determine prevalence of hyponatremia in acute medical admissions in Northern Australasia.MethodsWe studied 469 consecutive acute medical admissions to a hospital in Australia's Far North Queensland during the colder months of June and July 2012. Prevalence of hyponatremia and its relationship with gender, age, diagnosis and prognosis in acute medical admissions were investigated.ResultsOn admission, hyponatremia (plasma sodium <136 mmol/L) was present in 39.4% of patients, with mild (130-135 mmol/L), moderate (126-129 mmol/L) and severe (<126 mmol/L) hyponatremia being present in 25.2%, 10.7% and 3.6% respectively. Overall, adding together admission hyponatremia with that developing during admission, 45.2% of patients were affected with 11.5% moderate hyponatremia cases and 4.1% severe ones. Hypokalemia and hyperkalemia were present in 17.0% and 18.1%, respectively. Overall, 275/469 patients (58.6%) presented with an electrolyte abnormality. There were significant correlations of hyponatremia with age but not with gender and in-hospital mortality. Prevalence of hyponatremia was high across all diagnostic categories.ConclusionsThe prevalence of hyponatremia appears to be high in the tropical North Australian population, being the highest prevalence reported amongst acute hospital admissions. The previously reported correlations with age and mortality do appear to hold good for this population with a high prevalence of electrolyte disorders. Further prospective analysis on a larger population in the area is needed to confirm our findings.