However, the adjustment does not account for early haemolysis during or after cardiac arrest, which is a common phenomenon.11 This is due to the very short half-life of free-haemoglobin (free-hgb) in contrast to NSE with a considerably longer half-life.12 Potentially, NSE might be elevated at 48 h due to release from destructed red blood cells during resuscitation.13 Therefore, it is essential to investigate if early haemolysis has an impact on the interpretation of NSE. Here, ENO2 is linked to cardiac arrest.