Evaluation of coagulopathy on veno-arterial ECMO (VA) extracorporeal membrane oxygenation using platelet aggregometry and standard tests: A narrative review

Abstract

Extracorporeal membrane oxygenation (ECMO) is an established therapy for patients with cardiac failure, pulmonary failure or cardiopulmonary failure. To suppress the activation of the coagulation cascade, anticoagulation is necessary. Unfractionated heparin (UFH) is typically used for achieving the levels of therapeutic anticoagulation (ACT 180-220). Recently, viscoelastic tests of coagulation such as thrombo-elastrographyc (TEG) and ROTEM are increasingly used as they have shorter turnaround time and provide sensitive information about composition of clot, clot strength which can be used to assess and treat the coagulopathy on ECMO patients. POC coagulation management with ROTEM and impedance aggregometry is now frequently used to determine first-line therapy with specific coagulation factor concentrates such as fibrinogen concentrates and prothrombin complex concentrates.

Extracorporeal circuit of ECMO causes both quantitative and qualitative dysfunction of platelets due to activation and consumption. All studies so far has indicated reduced platelet aggregation in adult patients during ECMO. There is a strong association between platelet count and platelet aggregation. A consumptive platelet state due to platelet adhering to the ECMO circuit will all cause an increased tendency of patients bleeding ECMO. This narrative literature review brings to light some literature points on the role of platelet aggregometry during ECMO. ECMO is a form of cardiopulmonary bypass if platelet aggregation is reduced in ECMO, then this could play a role for the development therapies, which would inhibit platelets and prevent coagulation activation within the ECMO circuit, thus reducing bleeding in ECMO improving mortality.