Prolonged unconsciousness in severe COVID-19 infection with veno-venous ECMO support

ABSTRACT

Objectives: Patients with severe COVID-19 infections have been shown to have prolonged periods of coma followed by meaningful neurological recovery. Therefore, neurological prognostication is challenging, particularly in those who require veno-venous extracorporeal membrane oxygenation (VV-ECMO) support. We hoped to evaluate which variables can be considered when trying to predict neurological recovery. Method(s) We conducted a case-control retrospective chart review of patients on VV-ECMO from March 2020 to January 2022. This time-frame was selected to limit the effect of post-pandemic changes in sedation practices. Our outcome was duration of unconsciousness, defined as days with GCS motor score <6. We first conducted a matched cohort analysis, comparing COVID and non-COVID patients. We then performed a Classification and Regression Tree (CART) analysis to determine the Relative Variable Importance (RVI) of clinical variables associated with duration of unconsciousness. Result(s) Our matched analysis included 52 patients, 27 (52%) of whom had COVID-19. There were no significant differences in the baseline characteristics of the groups (Table 1). Patients with COVID-19 had a significantly longer median duration on ECMO (p<0.001) and hospital length of stay (p=0.003). The median duration of unconsciousness was similar between COVID-19 and non-COVID patients (p=0.58). The CART analysis results (Figure 1) showed that the most important variables to predict duration of unconsciousness were successive variations in GCS (RVI 100%) and GCS standard deviation (RVI 99%). COVID positivity only had a weak predictability (RVI 4%). Conclusion(s) Our analysis has shown that in patients on VV-ECMO, those with COVID-19 spent a longer time on ECMO and in the hospital. While there was no significant difference in the duration of unconsciousness, we found that patients who had high fluctuations of GCS during ECMO had a shorter duration of coma. (Figure Presented).