The Early Change in Pa After Extracorporeal Membrane Oxygenation Initiation Is Associated with Neurological Complications

: Large decreases in Pa that occur when initiating extracorporeal membrane oxygenation (ECMO) in patients with respiratory failure may cause cerebral vasoconstriction and compromise brain tissue perfusion.: To determine if the magnitude of Pa correction upon ECMO initiation is associated with an increased incidence of neurological complications in patients with respiratory failure.: We conducted a multicenter, international, retrospective cohort study using the Extracorporeal Life Support Organization Registry, including adults with respiratory failure receiving ECMO via any mode between 2012 and 2017. The relative change in Pa in the first 24 hours was calculated as (24-h post-ECMO Pa - pre-ECMO Pa)/pre-ECMO Pa. The primary outcome was the occurrence of neurological complications, defined as seizures, ischemic stroke, intracranial hemorrhage, or brain death.: We included 11,972 patients, 88% of whom were supported with venovenous ECMO. The median relative change in Pa was -31% (interquartile range, -46% to -12%). Neurological complications were uncommon overall (6.9%), with a low incidence of seizures (1.1%), ischemic stroke (1.9%), intracranial hemorrhage (3.5%), and brain death (1.6%). Patients with a large relative decrease in Pa (>50%) had an increased incidence of neurological complications compared with those with a smaller decrease (9.8% vs. 6.4%;  < 0.001). A large relative decrease in Pa was independently associated with neurological complications after controlling for previously described risk factors (odds ratio, 1.7; 95% confidence interval, 1.3 to 2.3;  < 0.001).: In patients receiving ECMO for respiratory failure, a large relative decrease in Pa in the first 24 hours after ECMO initiation is independently associated with an increased incidence of neurological complications.