Background

Thrombocytopenia, hemorrhage and platelet transfusion are common in patients supportedwith venoarterial extracorporeal membrane oxygenation (VA ECMO). However, current literature is limited to smallsingle‑center experiences with high degrees of heterogeneity. Therefore, we aimed to ascertain in a multicenter studythe course and occurrence rate of thrombocytopenia, and to assess the association between thrombocytopenia,hemorrhage and platelet transfusion during VA ECMO.

Methods

This was a sub‑study of a multicenter (N = 16) study on transfusion practices in patients on VA ECMO,in which a retrospective cohort (Jan‑2018–Jul‑2019) focusing on platelets was selected. The primary outcomewas thrombocytopenia during VA ECMO, defined as mild (100–150·109/L), moderate (50–100·109 /L) and severe(< 50·10 9/L). Secondary outcomes included the occurrence rate of platelet transfusion, and the associationbetween thrombocytopenia, hemorrhage and platelet transfusion, assessed through mixed‑effect models.

Results

Of the 419 patients included, median platelet count at admission was 179·10 9/L. During VA ECMO, almost all(N = 398, 95%) patients developed a thrombocytopenia, of which a significant part severe (N = 179, 45%). One or moreplatelet transfusions were administered in 226 patients (54%), whereas 207 patients (49%) suffered a hemorrhagicevent during VA ECMO. In non‑bleeding patients, still one in three patients received a platelet transfusion. The strong‑est association to receive a platelet transfusion was found in the presence of severe thrombocytopenia (adjustedOR 31.8, 95% CI 17.9–56.5). After including an interaction term of hemorrhage and thrombocytopenia, this evenincreased up to an OR of 110 (95% CI 34–360).

Conclusions

Thrombocytopenia has a higher occurrence than is currently recognized. Severe thrombocytopenia is strongly associated with platelet transfusion. Future studies should focus on the etiology of severe thrombocytope‑ nia during ECMO, as well as identifying indications and platelet thresholds for transfusion in the absence of bleeding.