Astroglial protein S-100 is an early and sensitive marker of hypoxic braindamage and outcome after cardiac arrest in humans

Background-The results of early conventional tests do not correlate with ce rebral outcome after cardiac arrest. We investigated the serum levels of as troglial protein S-100 as an early marker of brain damage and outcome after cardiac arrest. Methods and Results-In 66 patients undergoing cardiopulmonary resuscitation after nontraumatic cardiac arrest, blood samples for the evaluation of S-1 00 were drawn immediately after and 15, 30, 45, and 60 minutes; 2, 8, 24, 4 8, and 72 hours; and 7 days after initiation of cardiopulmonary resuscitati on. Moreover, the serum levels of neuron-specific enolase were determined b etween 2 hours and 7 days. If patients survived for > 48 hours, brain damag e was assessed by a combination of neurological, cranial CT, and electrophy siological examinations. Overall, 343 blood samples were taken for the dete rmination of S-100. Maximum S-100 levels within 2 hours after cardiac arres t were significantly higher in patients with documented brain damage (survi vors and nonsurvivors, 3.70 +/-0.77 mug/L) than in patients without brain d amage (0.90 +/-0.29 mug/L). Significant differences between these 2 groups were observed from 30 minutes until 7 days after cardiac arrest. In additio n, the positive predictive value of the S-100 test at 24 hours for fatal ou tcome within 14 days was 87%, and the negative predictive value was 100% (P <0.001). With regard to neuron-specific enolase, significant differences b etween patients with documented brain damage and those with no brain damage were found at 24, 48, and 72 hours and 7 days. Conclusions-Astroglial protein S-100 is an early and sensitive marker of hy poxic brain damage and short-term outcome after cardiac arrest in humans.