Background The Emergency Bypass System (EBS, Terumo Corporation) and Permanent Life Support (PLS, MAQUET Cardiopulmonary GmbH) platforms differ in pump design and surface coating, which may influence hemocompatibility. This study compared the longitudinal hematological profiles and transfusion requirements of these systems.

Methods Adult patients who underwent extracorporeal membrane oxygenation were analyzed using 1:1 propensity score matching (74 matched pairs). The primary endpoints included hemoglobin and platelet trajectories during the first 5 days, which were analyzed using linear mixed-effects models.

Results In the matched cohort, both groups demonstrated statistically similar longitudinal declines in hemoglobin and platelet counts (p=0.525 and p=0.501, respectively). However, this apparent stability in the EBS group was achieved at a significantly higher hematological cost. Within 5 days, the EBS group required 25.5% more red blood cell transfusions (p<0.001) and 34.2% more platelet transfusions (p<0.001) than the PLS group. Multivariable analysis confirmed that the use of the PLS system was independently associated with a lower transfusion demand.

Conclusion Although laboratory trajectories were comparable during the acute phase, patients supported by EBS experienced a substantially higher transfusion burden. These findings suggest a masking effect, in which compensatory transfusions may obscure the accelerated blood cell consumption associated with EBS. Therefore, clinicians should remain vigilant regarding the potential hidden hematologic costs of EBS support, even when laboratory parameters appear stable.