O’Brien NF, et al. - In this prospective, observational, multicenter study performed in tertiary care PICUs, researchers assessed the changes to expected, age-related transcranial Doppler ultrasound variables during pediatric extracorporeal membrane oxygenation. Participants were 52 children 1 day to 18 years old requiring veno arterial extracorporeal membrane oxygenation. Daily transcranial Doppler ultrasound measurement of bilateral middle cerebral artery flow velocities was performed. Significantly lower flow velocities were observed in the middle cerebral arteries of children requiring extracorporeal membrane oxygenation as compared with published normative values for critically ill, mechanically ventilated, sedated children. In children suffering ischemic injury vs those who did not, no significant differences in measured systolic flow velocity, diastolic flow velocity, and mean flow velocity were evident. Increased pulsatility index was suggested as a marker for ischemic injury in young infants on extracorporeal membrane oxygenation.