AUTHOR=Fisser Christoph , Palmér Oscar , Sallisalmi Marko , Paulus Michael , Foltan Maik , Philipp Alois , Malfertheiner Maximilian V. , Lubnow Matthias , Müller Thomas , Broman Lars Mikael 

TITLE=Recirculation in single lumen cannula venovenous extracorporeal membrane oxygenation: A non-randomized bi-centric trial

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.973240

DOI=10.3389/fmed.2022.973240

ISSN=2296-858X

ABSTRACT=<sec><title>Background</title><p>Recirculation is a common problem in venovenous (VV) extracorporeal membrane oxygenation (ECMO). The aims of this study were to compare recirculation fraction (R<italic>f</italic>) between femoro-jugular and jugulo-femoral VV ECMO configurations, to identify risk factors for recirculation and to assess the impact on hemolysis.</p></sec><sec><title>Methods</title><p>Patients in the medical intensive care unit (ICU) at the University Medical Center Regensburg, Germany receiving VV ECMO with femoro-jugular, and jugulo-femoral configuration at the ECMO Center Karolinska, Sweden, were included in this non-randomized prospective study. Total ECMO flow (<italic>Q</italic><sub><italic>EC</italic></sub>), recirculated flow (Q<sub>REC</sub>), and recirculation fraction R<italic>f</italic> = Q<sub>REC</sub>/Q<sub>EC</sub> were determined using ultrasound dilution technology. Effective ECMO flow (Q<sub>EFF</sub>) was defined as Q<sub>EFF</sub> = Q<sub>EC</sub> * (1–R<italic>f</italic>). Demographics, cannula specifics, and markers of hemolysis were assessed. Survival was evaluated at discharge from ICU.</p></sec><sec><title>Results</title><p>Thirty-seven patients with femoro-jugular configuration underwent 595 single-point measurements and 18 patients with jugulo-femoral configuration 231 measurements. R<italic>f</italic> was lower with femoro-jugular compared to jugulo-femoral configuration [5 (0, 11) vs. 19 (13, 28) %, respectively (<italic>p</italic> &lt; 0.001)], resulting in similar Q<sub>EFF</sub> [2.80 (2.21, 3.39) vs. 2.79 (2.39, 3.08) L/min (<italic>p</italic> = 0.225)] despite lower Q<sub>EC</sub> with femoro-jugular configuration compared to jugulo-femoral [3.01 (2.40, 3.70) vs. 3.57 (3.05, 4.06) L/min, respectively (<italic>p</italic> &lt; 0.001)]. In multivariate regression analysis, the type of configuration, distance between the two cannula tips, ECMO flow, and heart rate were significantly associated with Rf [B (95% CI): 25.8 (17.6, 33.8), p &lt; 0.001; 960.4 (960.7, 960.1), <italic>p</italic> = 0.009; 4.2 (2.5, 5.9), p &lt; 0.001; 960.1 (960.2, 0.0), p = 0.027]. Hemolysis was similar in subjects with Rf &gt; 8 vs. ≤ 8%. Explorative data on survival showed comparable results in the femoro-jugular and the jugulo-femoral group (81 vs. 72%, <italic>p</italic> = 0.455).</p></sec><sec><title>Conclusion</title><p>VV ECMO with femoro-jugular configuration caused less recirculation. Further risk factors for higher R<italic>f</italic> were shorter distance between the two cannula tips, higher ECMO flow, and lower heart rate. R<italic>f</italic> did not affect hemolysis.</p></sec>