
fluid and electrolyte metabolism in nephrogenic diabetes insipidus
the body fluid volumes have been fol-
lowed in two infants with nephrogenic
diabetes insipidus.  without treatment both
patients had a low extracellular fluid
volume (ecv) and a normal to low-
normal total body water (tbw).  following
thiazide therapy (case 1) and during a
fluid deprivation test (case 2) a further
reduction of ecv and tbw was found.
untreated both patients revealed a se-
vere hypernatriemia without any increase
in the urinary aldosterone excretion.
the first patient had a cerebral atro-
phy and a rightsided hydronephrosis, a
higher diuresis and a lower concentration
capacity was found on this side.  the
patient was treated continuously with
thiazide.  when an ordinary house diet
was given this drug could only maintain
normal electrolytemia in combination
with spirolactone.  a considerable increase
in height and psychic development took
place during this combined treatment.
it is noted, that nephrogenic diabetes
insipidus may be present in infants with
unexplained fever and vomiting in the
absence of polydipsia and polyuria.  the
urine may even be hypertonic.
