Characteristics and risk factors of delirium in patients on veno-arterial extracorporeal membrane oxygenation

PurposeSparse data exist on delirium in VA-ECMO. We aim to describe the characteristics, risk factors, and outcomes of delirium in VA-ECMO.MethodsWe retrospectively reviewed adults's electronic medical records on VA-ECMO in our ECMO registry in 2016-2022. Delirium was assessed by the Confusion Assessment Method for the intensive care unit when patients scored -3 or above on the Richmond Agitation-Sedation Scale. The primary outcomes were delirium prevalence and the proportion of delirium-present days while on VA-ECMO support. Multivariable logistic regression was used to evaluate delirium risk factors.ResultsOf 208 patients (median [interquartile range] age: 53 [40-62]), 138 (66.3%) had delirium during ECMO. Delirium occurred on day 2.5 [1.0-7.0] of ECMO and was detected in 42% [20%-66%] of ECMO days. There were no differences in acute brain injury (24% vs 33%, <i>p</i> = .34) between patients with and without delirium. Survival analysis showed no significant association between delirium and 30-day mortality (<i>p</i> = .24). In multivariable analysis, ECMO day 1 arterial carbon dioxide partial pressure (adjusted odds ratio [aOR] = 1.29; 95% CI = 1.03-1.73), number of sedatives (aOR = 2.67; 95% CI = 1.68-2.95), and African American race/ethnicity (aOR = 16.45; 95% CI = 9.65-22.51) were associated with delirium.ConclusionsDelirium was present in 66.3% of VA-ECMO patients and was detected early during ECMO. Modifiable risk factors included multiple sedative agents and early hypercapnia. Delirium did not increase risk for mortality.