NEFL and cardiac arrest: Concentrations of NfL in children with both favorable and unfavorable outcomes numerically increased over the study days, potentially representing ongoing neuroaxonal injury.31,32 Our data are consistent with a single-center study15 involving children with cardiac arrest who experienced acute respiratory distress syndrome; that study found that NfL was associated with unfavorable outcomes at hospital discharge (as measured by Pediatric Cerebral Performance Category scores at discharge).