Guidelines for appropriate use of hypertonic (3%) saline (HS) for the
treatment of hyponatremia are ill-defined. We reviewed each infusion o
f HS in a 400-bed university hospital over a 1-year period. Of the 14
infusions, the hyponatremia (average serum sodium [Na+] 19.9 +/- 6.7 m
Eq/L) was chronic in 11 cases and acute in only 3. In only 2 patients
were there symptoms possibly attributable to hyponatremia, On the aver
age, more than 5 hours elapsed from the last measured serum Na+ level
to the initiation of HS infusion, and the next measured serum Na+ valu
e came more thin 6 hours later. HS should be reserved for symptomatica
lly hyponatremic patients, most of whom become acutely hyponatremic; A
target level for the serum Nac should be determined and a time-course
for correction set. The infusion should be started promptly and monit
ored frequently for the effect on the serum Na+ level and patient symp
toms.