Anzeige
Erschienen in:
24.06.2022 | Clinical Quiz
Chronic hyponatremia in a 19-month-old child with gross developmental delay: Answers
Erschienen in: Pediatric Nephrology | Ausgabe 4/2023
Einloggen, um Zugang zu erhaltenExcerpt
1.
Based on these findings what is the presumptive diagnosis?
Clinical presentation and test results are suggestive of syndrome of inappropriate antidiuretic hormone secretion (SIADH) including its various subtypes like reset osmostat (RO) and nephrogenic syndrome of inappropriate antidiuresis (NSIAD). Other possible causes include cerebral salt wasting (CSW), salt loosing tubulopathies, and aldosterone deficiency.
2.
What further testing will reveal the diagnosis?
The recommended work-up includes serum and urine electrolytes, fludrocortisone and sodium challenge tests, water loading test (rarely used), and genetic testing for AVPR2 mutation (NSIAD). In our patient, genetic testing showed AVPR2 X-linked mutation c.409C>T p.R137C, which is consistent with NSIAD.
4.
What are the treatment options and prognosis for this patient?
Treatment options for NSIAD include water restriction, sodium supplementation, and 30% oral urea, with water restriction the mainstay of treatment. Oral urea is an effective, safe, and inexpensive treatment which causes normalization of electrolyte abnormalities. Furosemide and demeclocycline have some role in treatment of hyponatremia in adults. The prognosis depends on the time of onset and degree of hyponatremia. Late diagnosis can potentially lead to severe hyponatremia and poor outcome in infancy when the child is dependent upon parental feeding behavior. Once the thirst mechanism develops, the prognosis is usually favorable.