S100B is a sensitive but not specific prognostic index in comatose patients after cardiac arrest

The aim of this study was to compare serum S100B levels and EEG findings as prognostic indexes in comatose (GCS<8) patients after cardiac arrest.

S100B serum levels were assessed 12 h after the event and EEG findings were recorded within 24 h in comatose cardiac arrest survivors. At hospital discharge, patients were divided into groups according the Glasgow-outcome scale (GOS): group 1 with bad neurological outcome and group 2 with good neurological outcome (GOS 4-5). S100B levels and EEG findings were retrospectively tested about their predictive value.

S100B has a very low specificity (37.5%) while S100B sensitivity is 100%. EEG findings specificity is 75% and sensitivity 50%. S100B was not significantly lower in patients who recovered consciousness (10 patients) and there was no significant difference in EEGs findings between group 1 and 2.

The association of serum S100B levels with EEG might be helpful when used together to formulate outcome in comatose patients within 24 h after cardiac arrest. However, increased levels of S100B 12 h after a cardiac arrest might be expression of a still amendable brain damage.