Modeling serum level of S100β and bispectral index to predict outcome after cardiac arrest.
- Cardiovascular Research Unit
OBJECTIVES: To evaluate multimodal prognostication in patients after cardiac arrest. BACKGROUND: Accurate methods to predict outcome after cardiac arrest are lacking. METHODS: Seventy-five patients with cardiac arrest treated by therapeutic hypothermia after cardiac resuscitation were enrolled in this prospective observational study. Serum levels of neuron-specific enolase (NSE) and neuron-enriched S100 beta (S100B) were measured 48h after cardiac arrest. Bispectral index (BIS) was continuously monitored during the first 48h after cardiac arrest. RESULTS: The primary end-point was neurological outcome, as defined by the cerebral performance category (CPC) at 6-months follow-up: scores 1-2 indicated good outcome and scores 3-5 poor outcome. The secondary end-point was survival. 46 (61%) patients survived at 6-months and 41 (55%) patients had CPC 1-2. Levels of NSE and S100B were higher in patients with poor outcome compared to patients with good outcome (4-fold and 10-fold, respectively; P<0.001). BIS was lower in patients with poor outcome (10-fold, P<0.001). NSE, S100B or BIS alone predicted neurological outcome with areas under the receiver-operating characteristic curve (AUC) above 0.80. Combined determination of S100B and BIS had an incremental predictive value (AUC=0.95). S100B improved discriminations based on BIS (P=0.0008), and BIS improved discriminations based on S100B (P<10-5). Patients with S100B level above 0.03 mug/L and BIS below 5.5 had a 3.6-fold higher risk of poor neurological outcome (P<0.0001). S100B and BIS predicted 6-months mortality (log-rank statistic 50.41, P<0.001). CONCLUSIONS: Combined determination of serum level of S100B and BIS monitoring accurately predicts outcome after cardiac arrest.