| ABSTRACT: |
STUDY DESIGN. Patients undergoing spinal surgery
were monitored for sodium balance, fluid type, and volume input and output
during surgery and for the first 3 postoperative days. OBJECTIVE. To prospectively
document the true incidence of the syndrome of inappropriate antidiuretic
hormone secretion and hyponatremia, and identify risk and protective factors
for the development of the syndrome of inappropriate antidiuretic hormone
secretion after spinal surgery. METHODS. Data on medical history, surgical
procedure, estimated blood loss, and volumes and types of intraoperative
and postoperative fluids were collected on 116 consecutive spinal surgery
patients during March to July 1992. RESULTS. One hundred one spinal operations
in 96 patients were evaluated. There were 48 males and 48 females, with
a mean age of 52 years (range, 16 to 90 years). Hyponatremia developed in
45 (44.6%) patients. The etiology of hyponatremia was the syndrome of inappropriate
antidiuretic hormone secretion in seven patients (6.9%), hypovolemia in
19 patients (18%), and other causes in six patients. CONCLUSIONS. Spine
patients are at risk for hyponatremia and the syndrome of inappropriate
antidiuretic hormone secretion. The incidence of the syndrome of inappropriate
antidiuretic hormone secretion was 6.9%. Serum sodium should be monitored
postoperatively. Patients who undergo a revision operation have an approximately
two to four times greater risk of being affected by the syndrome of inappropriate
antidiuretic hormone secretion than those who have primary surgery. |