Four cases of severe hyponatremia occurring during operative hysterosc
opy and resulting in a 50% death rate are presented. Either glycine 1.
5% or sorbitol 3% was used for uterine irrigation in each circumstance
. Although careful monitoring of fluid intake and output is important,
more precise methods of tracking medium intrusion into the vascular s
pace may be required. Serial serum sodium, central venous pressure, an
d plasma osmolality determinations are recommended to establish a time
ly diagnosis of hyponatremia and hypoosmolality. Rapid and aggressive
management of significant hyponatremia (Na < 120 mmol/liter) should be
instituted using 3%-5% sodium chloride solution and furosemide to att
ain the goal of elevating serum sodium to 130-135 mmol/liter with 24 h
. Young women appear to be more susceptible to the sequelae of postope
rative hyponatremia, e.g., cerebral edema, than are their male counter
parts because of efficiency differences in their cerebral sodium pump
function. Liquid distending media with osmolalities in the range of 28
0 mOsm/liter would offer a greater margin of patient safety than eithe
r sorbitol or glycine for operative hysteroscopy.