Anticoagulation in pediatric extracorporeal membrane oxygenation (ECMO) presents unique challenges due to developmental hemostasis, coagulation factor production, and response to anticoagulants. This process requires close monitoring to prevent bleeding and thrombotic events. Limited data exist on how traditional coagulation tests correlate with these complications in this population in the first 24 h after ECMO cannulation.

This institutional review board-approved retrospective review was conducted on 126 children requiring ECMO between January 2017 and March 2022. Pre- and post-cannulation partial thromboplastin time (PTT), prothrombin time (PT), international normalized ratio (INR), hemoglobin, platelet count, and fibrinogen were collected. Also measured were initial activated clotting time (ACT), time to reach target ACT post-heparin bolus (≤250 s), initial unfractionated heparin (UFH) infusion rate, and post-cannulation antithrombin III activity (ATIII).

Compared to those who did not experience complications, patients who experienced bleeds showed a longer time until target ACT was reached (p = 0.003), prolonged post-cannulation PT and INR (p = 0.002 for both), lower pre- and post-cannulation fibrinogen levels (p = 0.008 and p = <0.001, respectively), and lower post-cannulation platelet counts (p = 0.035). However, those who experienced thrombotic complications showed only higher pre-cannulation fibrinogen levels (p = 0.017).

Our data shows that fibrinogen is an important parameter which defines the risk of early bleeding or thrombotic complications during the first 24 hours of ECMO cannulation. Attention to these baseline and immediate post-cannulation laboratory values may be important to determine initial bolus dosing and adjustment of anticoagulation in these patients. Continued multi-center collaboration to determine the utility of incorporation of other coagulation studies, like anti-factor Xa and viscoelastic assays, is needed.