[Oxytocin and syndrome of inappropriate secretion of antidiuretic neonatal hormone. Case report of early severe hyponatremia and literature review]. / Oxitocina y sindrome de secreción inapropiada de hormona antidiurética neonatal. Reporte de un caso de hiponatremia severa temprana y revisión de la bibliografia.

This is a clinical case presentation of a full term newborn infant who suffered severe hyponatremia and early seizures, associated with maternal fluid overload with electrolyte free solutions and high doses of oxytocin for labor augmentation. Although this condition has been recognized since the 1960's with isolated reports, this particular case has features that needs further investigation, not only for the unsually severe hyponatremia, but most importantly we think, for the prominent signs of fluid retention, the infant had, that suggest excessive antidiuretic activity probably due to oxytocin. These findings are consistent with syndrome of inappropriate secretion of antidiuretic hormone. Although until now there is no proof that oxytocin by itself produces this syndrome. We think the association is possible in certain clinical circumstances, such as those found in this case. We also, briefly discussed the pathophysiology of perinatal hyponatremia, the neonatal treatment of this condition and the current guidelines for the women in labor. Hyponatremia should not be considered a benign condition, since in the neonate, it may affect brain function.

Epidermal nevus syndrome with hypermelanosis and chronic hyponatremia.

Epidermal nevus syndrome is seldom encountered, and its association with hypermelanosis and the chronic syndrome of inappropriate antidiuretic hormone secretion (SIADH) has never been reported. A male neonate who developed intractable seizures and hyponatremia soon after birth is reported. He had alopecic patches on the scalp at birth. Large areas of skin hyperpigmentation, and epidermal nevi developed gradually. The clinical picture of hypotonic hyponatremia, high urine osmolality, elevated urine sodium, and euvolemia was compatible with SIADH. The seizures did not correlate with the hyponatremia, and no other cause for the seizures could be identified. The hyponatremia became chronic and was treated with a direct supply of sodium chloride. The development of the patient was markedly delayed at the last visit when he was 1 year of age. It is suggested that hypermelanosis and chronic SIADH may also be a variant presentation of epidermal nevus syndrome.