Hyponatremia in children under 100 days old: incidence and etiologies

Hyponatremiais one of the most common electrolyte disorders in hospitalized children. The underlying mechanisms are poorly understood and potentially multifactorial, making management difficult, particularly in neonates. This retrospective study aimed to determine the incidence and etiologiesof hyponatremiain hospitalized children under the age of 100 days, in our pediatric tertiary care hospital over a 1-year period. The etiologyof hyponatremiawas determined by reviewing the data noted in each patient’s medical reports. Neonatal hyponatremiahad a prevalence of 4.3% (86/2012 patients) and was mostly hospital-acquired (74/86 patients). Fifty-nine patients (68.9%) were preterm neonates. The etiologywas iatrogenic in 26 cases (30.2%). In other cases, hyponatremiawas due to transient (23 patients, 26.7%) or genetic abnormalities of the renal mineralocorticoidpathway (3 patients, 3.4%), SIADH (12 patients, 14%), digestive disease (3 patients, 3.5%), acute renal failure (3 patients, 3.5%), or heart failure (1 patient, 1.2%).