Clinical outcomes according to cannula configurations in patients with acute respiratory distress syndrome under veno-venous extracorporeal membrane oxygenation: a Korean multicenter study

Background Recirculation during veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a known drawback that limits sufficient oxygenation. This study aimed to compare the short-term oxygenation and long-term mortality based on cannula configuration in patients with acute respiratory distress syndrome (ARDS) who receive VV-ECMO, especially in the absence of newly developed dual-lumen, single cannula. Methods Data of patients with severe ARDS who received VV-ECMO from 2012 to 2015 at six hospitals were retrospectively analyzed. Primary outcomes were the partial pressure of oxygen (PaO 2 ) at 1, 4, and 12 h after ECMO initiation and 180-day mortality. Results Patients ( n = 335) were divided into two groups based on the return cannula site: femoral vein ( n = 178) or internal jugular vein ( n = 157). The propensity score matching analysis generated 90 pairs, and baseline characteristics at admission, including PaO 2 , were similar between the groups. PaO 2 at 1, 4 and 12 h after ECMO initiation were not different according to cannula configuration. Moreover, the increment in oxygenation from the baseline values was not different between the femoral and jugular group. PaCO 2 level at 1, 4 and 12 h were significantly lower in the jugular group. The two groups did not differ in terms of mortality at 180 days after ECMO, however more cannula-related complications occurred in the jugular group. Conclusion Regardless of the cannula configuration, patients with ARDS managed with VV-ECMO showed comparable clinical outcomes in terms of short-term oxygenation and long-term mortality. Nevertheless, further well-designed randomized control trials are warranted.