Serum S-100B and interleukin-8 as predictive markers for comparative neurologic outcome analysis of patients after cardiac arrest and severe traumatic brain injury*

Abstract

OBJECTIVE: To compare S-100B and interleukin-8 serum values on scene/at admission and 12 hrs later with respect to neurologic long-term outcome 12 months after cardiac arrest and return of spontaneous circulation, as well as after severe traumatic brain injury. DESIGN: Prospective comparative cohort study. SETTING: On scene; intensive care units of a university hospital. PATIENTS: Twenty patients with out-of-hospital cardiac arrest. Twenty patients with severe traumatic brain injury. INTERVENTIONS: Therapy was adjusted to the standards of modern prehospital and intensive care management by physicians who were not involved in the study. MEASUREMENTS AND MAIN RESULTS: First median S-100B values of the cardiac arrest group (4.42 ng/mL) mounted as high as those of the traumatic brain injury group (4.11 ng/mL). Within 12 hrs, S-100B levels significantly decreased to 0.75 ng/mL in cardiac arrest patients and to 0.68 ng/mL in traumatic brain injury patients but remained significantly elevated compared with the controls (0.04 ng/mL). Interleukin-8 levels of the cardiac arrest patients on scene (30.33 pg/mL) were clearly elevated above normal (12.60 pg/mL) and increased significantly to 101.40 pg/mL after 12 hrs. They showed no significant difference compared with those of the traumatic brain injury patients (78.75 pg/mL and 96.00 pg/mL, respectively). Multivariate Cox regression analysis in cardiac arrest patients identified only the S-100B level measured 12 hrs after study entry as an independent predictor for unfavorable neurologic outcome according to the Glasgow Outcome Scale score. In contrast, S-100B as well as interleukin-8 levels quantified 12 hrs after admission significantly predicted an unfavorable neurologic course in the traumatic brain injury group. CONCLUSIONS: Significantly elevated S-100B and interleukin-8 serum levels 12 hrs after cardiac arrest suggest that primary brain damage and systemic inflammatory response are comparably serious with that of traumatic brain injury. In both collectives, increased S-100B values measured 12 hrs after insult correlated well with an unfavorable neurologic outcome after 12 months.