Neurological symptoms in an acute respiratory pattern: when Na matters

The appearance of neurological symptoms in an acute respiratory pattern, once hypoxia and hypercapnia are ruled out secondary to severe respiratory failure, should lead us to think about an underlying hyponatremia, forming part of a syndrome of inappropriate secretion of antidiuretic hormone (SIADH). This hydroelectrolytic alteration has been considered a factor of poor prognosis in the evolution of the respiratory process, so it is desirable to detect it early and correct it. We present the case of an infant who debuted with hypoactivity and apnea pauses prior to the respiratory symptoms of bronchiolitis.