Prognostic value of S100B protein in carbon monoxide-poisoned rats.

Objective: To assess the possible role of S100B, a structural protein of astroglial cells, as a biochemical marker in acute carbon monoxide-poisoned rats and to compare its prognostic value with consciousness level, which is one of the major parameters for treatment decision in acute carbon monoxide poisoning.

Design: Nonrandomized, controlled interventional trial.

Setting: University laboratory.

Subjects: Male Wistar rats weighing 263 +/- 18 g.

Interventions: The rats were exposed to a mixture of 3000 ppm carbon monoxide in air for 60 mins (group 1) and a mixture of 5000 ppm carbon monoxide in air for 30 mins (group 2). Blood samples were taken from the jugular vein just before and immediately after the carbon monoxide poisoning. The level of consciousness was evaluated at the end of the exposure, and the survival rate was monitored for 7 days. The S100B concentrations were measured with a commercial immunoluminometric assay.

Measurements And Main Results: In the first group, the unconscious rats after carbon monoxide exposure had significantly higher S100B levels compared with the rats without loss of consciousness. In the second group, the unconscious rats that later died had significantly higher S100B levels compared with the unconscious rats that survived. The S100B levels of all conscious and unconscious surviving rats were not significantly different. The serum level of S100B below 0.44 microg/L predicted survival of carbon monoxide-poisoned rats, with a sensitivity of 100% and a specificity of 86%.

Conclusions: Acute carbon monoxide poisoning is associated with elevated S100B levels. S100B is a better predictor of final outcome than the consciousness level, so it could be used as a prognostic parameter for acute carbon monoxide poisoning in rats.