Determinants of Survival in Patients with Extracorporeal Support

Objectives: Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) help in bridging critical cardiopulmonary situations. Although some experience has been gained over the last years, many patients supported by either device cannot be weaned from it. We aimed to find determinants of survival.

Methods: We analyzed data from patients, supported by either ECMO or ECLS in our clinic between April 2010 and January 2016, retrospectively. Descriptive statistical analysis was performed. Multivariate analysis was performed by logistic regression. We compared survivors and non-survivors in the ECMO group and ECLS group, respectively.

Results: General demographics were comparable in both groups (p = n.s.). During the observation period, 43 ECMO devices and 97 ECLS devices were implanted. Of 43 ECMO cases, 28 patients (65%) died, 20 patients (47%) were weaned and 15 patients (35%) were discharged from the intensive care unit (ICU). Of 97 ECLS cases 78 patients (80%) died, 21 patients (22%) were weaned and 19 (20%) were discharged. Longer duration of treatment was significantly associated with better survival in ECLS patients (p = 0.009), but not in ECMO patients (p = 0.18). According to descriptive statistics, more patients tended to survive, when the device was implanted earlier, but this was not significant in multivariate analysis (p = 0.329). Antegrade versus retrograde blood flow had no impact on survival (p = 0.513), neither had diagnosed coronary heart disease (p = 0.362). Right ventricular dysfunction did not worsen survival (p = 0.454). In 38.5% of all cases bleeding complications occurred, but had no impact on survival (p = 0.653).

Conclusion: As previously shown in the existing literature, survival was better in ECMO patients than in ECLS patients. The only determinant of survival in our study population was duration of extracorporeal support in ECLS patients. Surprisingly, site of cannulation seemed to have no effect on survival, neither had right ventricular failure in our ECLS group. Bleeding complications did not worsen survival significantly. Beneficial effects of longer treatment hours might be facilitated by faster clinical decision making and earlier implantation.