The platelet trigger at which to transfuse platelets to prevent bleeding complications in patients supported with extracorporeal membrane oxygenation (ECMO) is unclear. We aimed to elucidate the association between platelet count and bleeding sequelae in this patient population.

We conducted a single-center retrospective study of all adult patients who received ECMO support from 2017 to 2022. Patients were stratified into two groups: “non-thrombocytopenic” (>30 × 10³ cells /μL) versus “thrombocytopenic” (≤30 × 10³ cells /μL). Multivariable logistic regression was used to determine the association between thrombocytopenia and bleeding complications; covariates were selected a priori. A post-hoc analysis investigating platelet transfusion status and nadir platelet count as an ordinal variable was also performed.

Of 291 VV- and VA-ECMO patients, 69 (24%) were categorized as “thrombocytopenic” and 144 (50%) experienced at least one major bleeding event. Compared to “non-thrombocytopenic” patients, “thrombocytopenic” patients were more likely to be male (p = 0.049), to require veno-arterial central canulation (p < 0.001), and to have been on dialysis (p < 0.001). Confounded by a 72% prophylactic transfusion rate, “Thrombocytopenia” was not associated with an increased risk of major bleeding (aOR: 0.59 [95% CI: 0.31–1.10]). However, in patients with a nadir platelet count between 31 and 50 × 10³ cells/μL, the 63% with a prophylactic platelet transfusion had a significant reduction in major bleeding complications (p = 0.003).

Our findings suggest that a platelet transfusion trigger of ≤50 × 10³ cells/μL is of benefit for prophylaxis against bleeding during ECMO support.