[Anesthetic management of a patient with severe hyponatremia]

A 79 year old man, with left femoral neck fracture, was scheduled for an elective operation. After admission, severe hyponatremia probably due to diuretics developed. No neurological abnormalities were observed before surgery. He recovered from anesthesia with no problems. But on the 5th postoperative day he showed transient unresponsiveness. Grand mal seizures were also seen after the serum Na level had recovered to around 130 mEq.l-1. This case shows that in the management of severe hyponatremia, the discrimination between acute and chronic hyponatremia seems to be important.