Neuron-Specific Enolase Serum Levels Predict Severe Neuronal Injury after Extracorporeal Life Support in Resuscitation

OBJECTIVES:

Extracorporeal life support (ECLS) is a rescue option in critically ill patients. Since fast available and appropriate for respiratory and circulatory failure, it is frequently applied in resuscitation scenarios. Neurological injury is a complication common in ECLS patients limiting outcome, particularly after resuscitation. In this study, the institutional ECLS database was used to correlate neuron-specific enolase (NSE) serum peak values with outcome of patients supported with venoarterial (VA) ECLS during cardiopulmonary resuscitation (CPR).

METHODS:

From January 2011 to August 2012, 31 patients were provided with a VA ECLS during CPR (external cardiac massage). Serum NSE peaks were monitored and correlated with neurological outcome and hospital mortality. Patients were divided into two groups with mild-to-moderate and high NSE levels (cut-off value 100 μg/l).

RESULTS:

High NSE levels were seen in 7 patients (mean 218 ± 155 μg/l) and mild-to-moderate levels in 24 patients (50 ± 23 μg/l, P = 0.0001). Duration of extracoporeal support was comparable in both groups (6.3 ± 7.5 vs 5.0 ± 4.5 days, P = n.s.). Patients with mild-to-moderate NSE levels were significantly older than those with high NSE levels (58 ± 16 vs 44 ± 15 years, P = 0.02). Six patients with high NSE levels (86%) developed severe neurological complications. Though 4 patients could be weaned from extracorporeal support, hospital mortality was 86% (6 patients). In contrast, patients with mild-to-moderate NSE levels had a hospital mortality of 46% (11 patients). Eighteen patients (75%) could be weaned from the device, and incidence of major neurological events was 29% (6 patients) only. Serum pH and lactate levels before ECLS implantation were significantly lower in patients with mild-to-moderate NSE values (pH: 7.23 ± 0.04 vs 6.93 ± 0.12, P = 0.039; lactate: 106 ± 11 vs 161 ± 16 mg/l, P = 0.023).

CONCLUSIONS:

High NSE serum levels after ECLS correspond to poor neurological outcome and considerable mortality. Therefore, early neuroimaging is reasonable for determining therapeutic strategies in patients with high NSE peaks after resuscitation and extracorporeal support.