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

The Diagnosis of Salt Poisoning Leading to Hypematraemia in Children – September 2009
4. Causes of hypernatraemia
4.1 Causes of hypernatraemia in children (and adults) other than
excessive sodium intake
Clinical question
What are the possible causes of hypernatraemia other than excessive sodium intake
reported in children (and adults)?
Reports of causes of hypernatraemia other than excessive sodium intake have been
identified via a literature search. These have been categorised under the headings suggested
by Haycock. 27 Causes of excessive sodium intake are covered in the next sections.
4.1.1 Water depletion
4.1.1.1 Lack of water intake
Inadequate breast milk
As well as the case series already described (see section 3.1 on the incidence of
hypernatraemia), there are many individual case reports 28-62 from different parts
of the world, including some with fatal consequences 56 . One case report was of
a baby with glucose-galactose malabsorption 63 , where the hypernatraemia was
probably secondary to watery diarrhoea.
Several of these publications 33, 36, 37, 39, 40, 43, 58 suggest that high concentrations
of sodium in breast milk are at least partly responsible for the hypernatraemia.
This is almost certainly wrong 64 . The concentrations described (e.g. 47 mmol/L
in the paper by Peters 33 ) are less than the concentration of sodium that would be
used to correct hypernatraemic dehydration: the usual recommendation for initial
correction is isotonic saline (sodium concentration 154 mmol/L).
The true cause of breast-feeding associated hypernatraemia is inadequate
water intake, insufficient to replace the high insensible water losses that are
typical of the newborn infant.
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