Risk factors associated with bleeding complications during veno-venous extracorporeal membrane oxygenation: A single center retrospective study

Objective: Bleeding complications during veno-venous extracorporeal membrane oxygenation (VV-ECMO) management could be critical and worsen patient outcomes. We hypothesized that high APTT value, low platelet count during VV-ECMO and performing mobilization defined as rehabilitation at the level of sitting over the bed or higher are risk factors for bleeding complications based on current literature. Methods: This was a single-center retrospective observational study aiming to identify the risk factors of bleeding complications during VV-ECMO management. The patients who received VV-ECMO treatment between December 2012 and March 2020 were included. The exclusion criteria were followings: VV-ECMO only during surgical operation and because of COVID-19induced respiratory failure. The definition of bleeding complications followed Extracorporeal Life Support Organization (ELSO) guideline. The primary outcome was the risk assessment of three hypothesis, APTT, platelet count, and mobilization, against bleeding complications during VV-ECMO which were analyzed by multivariate logistic regression analysis with covariables of clinical important factors: age, gender, BMI, APACHEII, and SOFA. Results: Among 59 enrolled patients, 31 patients (53%) experienced bleeding complication that met ELSO criteria. The frequent bleeding sources included cannulation site, gastrointestinal tract, and nasal/oropharyngeal region. The baseline characteristics between the two groups were not significantly different. No significant difference in mortality (p=0.73) were seen, while longer days on ECMO support (p< 0.001) and longer length of ICU stay (p=0.02) were shown in the bleeding group. According to the multivariate logistic analysis, APTT [OR 1.04, 95% CI 1-1.08, p=0.034] was significantly associated with bleeding complications. Platelet count (p=0.72) and mobilization (p=0.064) demonstrated no association with bleeding complications. Conclusions: In our study, mobilization and platelet count during ECMO treatment were not independent factors for bleeding complications during VV-ECMO, while APTT was significantly associated with independent risk factor for bleeding complications.