Serum neuron-specific enolase and S-100β levels as prognostic follow-up markers for oxygen administered carbon monoxide intoxication cases.

Serum neuron-specific enolase (NSE) and S-100β levels are considered novel biochemical markers of neuronal cell injury. In this study, the initial and post-treatment levels of NSE and S-100β were compared in carbon monoxide (CO) poisoning patients, who received normorbaric oxygen (NBO) or hyperbaric oxygen (HBO) therapy. Forty consecutive patients with acute CO poisoning were enrolled in this prospective, observational study. According to their clinical symptoms and observations, twenty patients were treated with NBO, and the other twenty with HBO. Serum S-100β and NSE levels were measured both at time of admission and 6 h later (post-treatment). Serum NSE and S-100β values decreased significantly in both of the therapeutic modalities. The initial and post-treatment values of NSE and S-100β in NBO or HBO patients were comparable. A clear negative correlation was observed between the decrease of NSE and S-100β levels and initial blood carboxyhemoglobin levels. In conclusion, the present results suggested the use of serum S-100β and NSE levels as indicators for brain injury. Due to the significant increase of their values with oxygen therapy, they may also be useful as prognostic follow-up markers. However, the current findings reflected no difference between the efficacy of NBO or HBO therapy.