We have read with interest the work by Helms et al., a single-center study with 30 patients (16 on veno-venous and 14 on veno-arterial extracorporeal membrane oxy-genation (ECMO)), with a total of 214 ECMO days [1]. Patients were examined with standard coagulation assays (platelet count, prothrombin time, anti-Xa, activated partial thromboplastin time (aPTT), and D-dimer), and the occurrence of bleeding complications was registered. The study finds that the degree of anticoagulation or low platelet count is not associated with bleeding, whereas an increase in D-dimer shows a significant association with bleeding. The timing of bleeding in relation to blood sampling is not accounted for, and fibrinogen levels are not presented. The study concludes that due to the asso-ciation between increased D-dimer and bleeding compli-cations, hyperfibrinolysis may be related to bleeding risk in ECMO patients.