Background and objectives: Despite the common occurrence of neurologic complications during extracorporeal membrane oxygenation (ECMO) support, data on long-term neuropsychiatric, neurocognitive, and functional outcomes are sparse. We aimed to determine the prevalence of long-term neuropsychiatric symptoms, neurocognitive and functional impairment, and favorable neurologic outcomes in adult patients who receive ECMO.
Methods: PubMed, Embase, Cochrane, Web of Science, and Scopus were searched for text related to ECMO and neuropsychiatric, neurocognitive, and functional outcomes from inception to May 3, 2023. Our primary outcome was the prevalence of neuropsychiatric symptoms (pain/discomfort, anxiety, depression, posttraumatic stress disorder [PTSD], and sleep disturbance) at long-term (≥6 months) follow-up. Our secondary outcomes were the prevalence of neurocognitive impairment (memory, attention, and reasoning), functional impairment (daily activities, physical activity/mobility, and personal/self-care), and favorable neurologic outcomes (Cerebral Performance Category ≤2, modified Rankin scale ≤3, or Glasgow Outcome Scale ≥4). This study was registered in PROSPERO (CRD42023420565).
Results: We included 59 studies with 3,280 patients (median age 54 years, 69% male). The cohort consisted of 86% venoarterial (VA)-ECMO (n = 2,819) and 14% venovenous (VV)-ECMO (n = 461) patients. More than 10 tools were used to assess neuropsychiatric and neurocognitive outcomes, indicating a lack of standardization in assessment methodologies. The overall prevalence of neuropsychiatric symptoms was 41% (95% CI 33%-49%): pain/discomfort (52%, 95% CI 42%-63%), sleep disturbance (37%, 95% CI 0%-98%), anxiety (36%, 95% CI 27%-46%), depression (31%, 95% CI 22%-40%), and PTSD (18%, 95% CI 9%-29%). The prevalence of neurocognitive impairment was 38% (95% CI 13%-65%). The prevalence of functional impairment was 52% (95% CI 40%-64%): daily activities (54%, 95% CI 41%-66%), mobility (41%, 95% CI 28%-54%), and self-care (21%, 95% CI 13%-31%). The prevalence of neuropsychiatric symptoms in VV-ECMO patients was higher than that in VA-ECMO patients (55% [95% CI 34%-75%] vs 32% [95% CI 23%-41%], p = 0.01), though the prevalence of neurocognitive and functional impairment was not different between the groups. The prevalence of favorable neurologic outcomes was not different at various follow-ups: 3 months (23%, 95% CI 12%-36%), 6 months (25%, 95% CI 16%-35%), and ≥1 year (28%, 95% CI 21%-36%, p = 0.68).
Discussion: A substantial proportion of ECMO patients seemed to experience neuropsychiatric symptoms and neurocognitive and functional impairments at long-term follow-up. Considerable heterogeneity in methodology for gauging these outcomes exists, warranting the need for standardization. Multicenter prospective observational studies are indicated to further investigate risk factors for these outcomes in ECMO-supported patients.