Brain injury during venovenous extracorporeal membrane oxygenation.

PURPOSE: The frequency of neurological events and their impact on patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO) are unknown. We therefore study the epidemiology, risk factors, and impact of cerebral complications occurring in VV-ECMO patients.

METHODS: Observational study conducted in a tertiary referral center (2006-2012) on patients developing a neurological complication (ischemic stroke or intracranial bleeding) while on VV-ECMO versus those who did not, and a systematic review on this topic.

RESULTS: Among 135 consecutive patients who had received VV-ECMO, 18 (15 assessable) developed cerebral complications on ECMO: cerebral bleeding in 10 (7.5 %), ischemic stroke in 3 (2 %), or diffuse microbleeds in 2 (2 %), occurring after respective medians (IQR) of 3 (1-11), 21 (10-26), and 36 (8-63) days post-ECMO onset. Intracranial bleeding was independently associated with renal failure at intensive care unit admission and rapid PaCO2 decrease at ECMO initiation, but not with age, comorbidities, or hemostasis disorders. Seven (70 %) patients with intracranial bleeding and one (33 %) with ischemic stroke died versus 40 % of patients without neurological event. A systematic review found comparable intracranial bleeding rates (5 %).

CONCLUSIONS: Neurological events occurred frequently in patients on VV-ECMO. Intracranial bleeding, the most frequent, occurred early and was associated with higher mortality. Because it was independently associated with rapid hypercapnia decrease, the latter should be avoided at ECMO onset, but its exact role remains to be determined. These findings may have major implications for the care of patients requiring VV-ECMO.