Outcomes of Weaning Trial from Veno-Arterial Extracorporeal Membrane Oxygenation Using Inflow-Outflow Bridging

Purpose The use of veno-arterial extracorporeal membrane oxygenation (ECMO) for cardiogenic shock support is increasing. Because the recovery period differs from patient to patient, a standard protocol for the timing and strategy of ECMO weaning-off is not well established. Inadequate length of ECMO support can critically affect a patient's outcome, so the evaluation of proper ECMO weaning-off is warranted. A longer weaning trial is preferred to rule out delayed cardiogenic shock, however a long low-flow ECMO wean presents the risk of ECMO thrombosis. At our center, an inflow-outflow bridging technique is aggressively used to evaluate hemodynamics and respiratory status while weaning patients off of ECMO. It allows us to simulate an off-ECMO status for an extended period of time, but is reversible and does not require ECMO discontinuation. Here, we analyzed the outcomes of our inflow-outflow bridging technique for ECMO weaning. Methods This is a single-center retrospective study of patients on veno-arterial ECMO from May 2016 to August 2018. 14 patients on whom we used the inflow-outflow bridging technique were analyzed. The pre-ECMO demographics, ECMO weaning success vs. abortion rates, post-ECMO survival to discharge and complications were analyzed. Figure 1 displays the technique. The outflow cannula is clamped, and then intermittently un-clamped to flash the cannula under proper anticoagulation. Results 14 weaning trials were performed on 14 patients. 12 patients had ECMO weaning-off and decannulation (85.7%). 2 patients underwent a weaning trial, but were deemed unsuitable for ECMO discontinuation (14.3%). 0 patients had stroke/distal embolism or bleeding complications due to ECMO weaning trial. Successful wean sensitivity was 100.0%. Conclusion Our ECMO weaning-off trial highlighted satisfactory rates of screening for ECMO wean. Further larger research will help to clarify our weaning sensitivity and develop an adequate protocol.