The differential diagnosis of hypernatraemia in children, with ...

The Diagnosis of Salt Poisoning Leading to Hypematraemia in Children – September 2009
Case reports of osmoreceptor dysfunction are therefore all in association with other
endocrine or structural brain abnormalities. They present with hypernatraemia and
adipsia. It is very important to distinguish such cases from hypernatraemia due to
salt poisoning, and specialist referral should be considered where this may be a
possibility.
Evidence statement
There are no case reports of otherwise normal children presenting with
isolated hypernatraemia being due to abnormal osmostats [Grade C].
Deliberate water restriction
As well as the abusive withholding of water already described, there are other
circumstances in which this may occur.
One adult case report describes a 24-year-old Italian man with nephrotic syndrome
due to amyloid disease who decided to restrict his fluid intake severely in order
to combat his hypoalbuminaemic oedema. 109 He was admitted to hospital with a
sodium of 193 mmol/L. He made a full recovery without significant neurological
complications after slow restoration of his fluid deficit.
There is also the potential for iatrogenic hypernatraemia from over-enthusiastic
restriction of fluids in intensive care settings.
4.1.1.2 Increased water loss
Increased renal loss
Central diabetes insipidus
Central diabetes insipidus is due to lack of vasopressin (antidiuretic hormone) release
from the pituitary gland. In diabetes insipidus sodium homeostasis is maintained
without hypernatraemia as long as the child has access to water. However, this is a
well-recognised cause of hypernatraemia both in children and adults.
Diabetes insipidus is a rare condition in children, with an estimated frequency
from all causes (including nephrogenic) of 5 per million children per year in
Caucasian populations. 110, 111 Causes include:
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