Combined Monitoring of rSO2 and SSEP during Cardiopulmonary Bypass and Postoperative Changes in Plasma Levels of S-100: Is Diagnostic Sensitivity for Detecting Brain Damage Improved?

Hiroshi Ohtake Atsuyoshi Oki Yoshiharu Okada
Masahiro Aiba Tadanori Kawada Toshihiro Takaba

(First Department of Surgery, Showa University School of Medicine, Tokyo, Japan)

Combined monitoring of rSO2 and SSEP is routinely performed during cardiopulmonary bypassiCPB), but it is not sensitive enough to detect focal lesions of the brain. Thus, we assessed whether simultaneous measurement of S-100 is able to enhance diagnostic sensitivity or not. Between September 1999 and February 2000, serial measurement of plasma levels of S-100 and SSEP and rSO2 monitoring during CPB were simultaneously performed in 26 consecutive patientsi19 men and 7 women). Ages ranged from 46 to 85imean 67}10years). Neurological complications developed in 5i19.2%). Among those patients, hemiplegia developed in 2, and dementia, temporary convulsion, and deep coma in 1 each. Three of them showed abnormally low rSO2 levels during surgery, but no patient showed abnormal change in SSEP waves after surgery. There was no significant difference in S-100 level 1 h after CPB between patients associated with or without neurological complications i1.98}0.48vs. 1.89}1.65j, however, its level 24 h after CPB remained significantly higher in patients with neurological complicationsi1.01}1.14vs. 0.22}0.24j. S-100 level 24 h after CPB appears to improve diagnostic sensitivity for detecting such focal brain damage lesions as those in which SSEP or rSO2 are not efficient enough to make a diagnosis. However, further study is required to evaluate how fast it can differentiate patients with and without brain damage.
@Jpn. J. Cardiovasc. Surg. 31F269-273 (2002)