Neurological prognostication during extracorporeal life support: Is NSE just another brick in the wall?

Abstract

The severe neurological impairment following direct brain ischemia and the reperfusion injury after resuscitation from cardiac arrest still represent a considerable social and economic healthcare burden. Even despite recent advances in post-resuscitation care, about 50% of patients experiencing return of spontaneous circulation following cardiac arrest die or have poor neurological outcome [ 1 Berdowski J. Berg R.A. Tijssen J.G. Koster R.W. Global incidences of out-of-hospital cardiac arrest and survival rates: systematic review of 67 prospective studies. Resuscitation. 2010; 81: 1479-1487 Abstract Full Text Full Text PDF PubMed Scopus (1258) Google Scholar , 2 Nielsen N. Wetterslev J. Cronberg T. Erlinge D. Gasche Y. Hassager C. et al. Targeted temperature management at 33 °C versus 36 °C after cardiac arrest. N Engl J Med. 2013; 369: 2197-2206 Crossref PubMed Scopus (1945) Google Scholar ]. To avoid any inappropriate treatment and provide valuable information for clinicians and families, early prognostication of the neurological outcome seems essential. A recent joint advisory statement by the European Resuscitation Council and the European Society of Intensive Care Medicine [ [3] Sandroni C. Cariou A. Cavallaro F. Cronberg T. Friberg H. Hoedemaekers C. et al. Prognostication in comatose survivors of cardiac arrest: an advisory statement from the European Resuscitation Council and the European Society of Intensive Care Medicine. Resuscitation. 2014; 85: 1779-1789 Abstract Full Text Full Text PDF PubMed Scopus (286) Google Scholar ] suggested how the use of biomarkers could provide advantages over electroencephalography and clinical examination due to the quantitative nature of the results and the independence from the effects of sedatives. Among the proposed biomarkers, elevated levels of neuron-specific enolase (NSE), released following injury to neurons, and thus likely to be correlated to the extent of the ischemic injury, are evocative of a poor neurological outcome [ [4] Sandroni C. Cavallaro F. Callaway C.W. Sanna T. D'Arrigo S. Kuiper M. et al. Predictors of poor neurological outcome in adult comatose survivors of cardiac arrest: a systematic review and meta-analysis. Part 1: patients not treated with therapeutic hypothermia. Resuscitation. 2013; 84: 1310-1323 Abstract Full Text Full Text PDF PubMed Scopus (152) Google Scholar ].