Early prediction of neurological outcome after cardiopulmonary resuscitation: A multimodal approach combining neurobiochemical and electrophysiological investigations may provide high prognostic certainty in patients after cardiac arrest

A reliable and reproducible method for precisely predicting the neurological outcome of patients with hypoxic-ischemic encephalopathy after cardiac arrest is urgently needed in neurological intensive care units. We prospectively investigated the predictive power of serum concentrations of neuron-specific enolase (NSE) and protein S-100B (S-100B) measured on days 1, 2, 3 and 7 as well as somatosensory-evoked potentials (SEPs) recorded within 48 h and on day 7 after cardiopulmonary resuscitation (CPR) in 27 patients (14 females, 13 males; mean age 61.3 ± 17.3 years) with hypoxic-ischemic encephalopathy. During the first 7 days after CPR, median values of NSE and S-100B were increased in patients who remained unconscious after CPR compared to those patients who regained consciousness (significance up to ≤ 0.001). The best predictor of negative outcome was an NSE cutoff point ≥ 43 μg/l on day 2; this had a sensitivity of 90.9% and a specificity of 100%. Additional use of S-100B on day 2 did not increase sensitivity, but this could be markedly increased by combining NSE and S-100B on days 1, 3 and 7. SEPs showing bilateral loss of cortical responses identified patients who did not regain consciousness with a specificity of 100%.