Salt depletion and dehydration in hypertensive preterm infants

Abstract

Three preterm infants presented with both severe or moderate arterial hypertension and dehydration due to increased water and sodium urinary excretion. In patient 1, water and sodium wasting were extremely severe and peaked at 575 ml/kg per day and 73 mEq/kg per day, respectively. In all infants, urinary water and sodium excretion dramatically decreased when hypertension resolved. The overall clinical data suggest a pressure natriuresis phenomenon.

Two cases of hyponatremic-hypertensive syndrome in childhood with renovascular hypertension

“…We hypothesized that the symptoms of HHS would develop in children only when the stenosis in the affected artery became so severe that revascularization by PTRA was impossible. In the literature, only seven case reports of pediatric HHS with renovascular hypertension were found [2,5,6,9,10,16]. Of the nine reported cases, including the present two, PTRA was technically successful in only one case [10].…”

The hyponatraemic hypertensive syndrome in a 2-year-old child with behavioural symptoms

“…If the contralateral kidney is well preserved and the hypertension of recent onset, the resulting hyponatraemia re-stimulates renin production leading to a vicious circle. The ®nal result is depletion of water, sodium, and potassium [1,2,5]. This explains the hyponatraemia, hypokalaemia, anorexia and dehydration in our patient.…”

“…It is more common in adult patients with malignant renovascular hypertension. To our knowledge, up to now few cases have been reported in the literature with regard to renovascular hypertension and hyponatraemia in children [2,5,10]. Moreover, the behavioural abnormalities in the history of this child are, as far as we know, a very exceptional initial presentation in this syndrome and have not yet been reported.…”

“…In general, this syndrome is observed in adults with renal vascular disease but is very rare in childhood [2,3,5,10]. The pathophysiology of this phenomenon is complex and principally based on counteracting mechanisms in both kidneys.…”

Doxapram and hypokalaemia in very preterm infants: Table 1

“…To our knowledge, an association between doxapram and hypokalaemia has not been previously reported. The physiopathological mechanisms underlying such an association remain unclear but could be mediated by pressure natriuresis 23. Doxapram has been reported to increase blood pressure which in turn may increase sodium excretion.…”