Platelet transfusions are routinely administered during neonatal ECMO, with an average of 1.3 platelet transfusions per day being administered while a patient is undergoing ECMO treatment. The cause of thrombocytopenia during ECMO largely involves platelet adherence to the oxygenator membrane. Platelet transfusions carry risks such as infections with bacteria or yeast, and development or worsening of pulmonary hypertension. It is likely that if fewer platelet transfusions can be administered during the ECMO run, the cumulative adverse effects of platelet transfusions would diminish and patient outcomes improve. In order to better understand platelet function during ECMO, the investigators plan to serially determine the circulating platelet mass, plasma platelet factor 4 concentration, megakaryocyte mass (estimated by plasma thrombopoietin concentration), and platelet function as quantified by PFA100. Any patient on ECMO will be eligible for this pilot study of 5 patients. By understanding changes in platelet function, we hope to design a future study that may modify the frequency or need for platelet transfusions during ECMO.

Platelet transfusions are routinely administered during neonatal ECMO, with an average of 1.3 platelet transfusions per day being administered while a patient is undergoing ECMO treatment.1 In general, a platelet transfusion is ordered for a patient on ECMO if the platelet count falls below 100,000/uL in order to prevent generalized hemorrhaging.1,2 The cause of thrombocytopenia during ECMO largely involves platelet adherence to the oxygenator membrane,3 but other mechanisms are also likely to be involved.4 Platelet transfusions carry risks as well as benefits.5 Infections with bacteria or yeast are the most commonly reported complications of platelet transfusions,6,7 but with multiple platelet transfusions the development or worsening of pulmonary hypertension may be another common adverse effect.8,9 Pulmonary hypertension can be the result of administering biologically active pro-inflammatory proteins (known to be present in platelet transfusions) into the venous circulation. Of note, the first capillary bed encountered will be within the pulmonary circulation.

It is likely that if fewer platelet transfusions could safely be administered during the ECMO run, the cumulative adverse effects of platelet transfusions would diminish and thereby patient outcomes might improve.

Inclusion Criteria:

• Any patient on ECMO will be eligible for study.

Any patient on ECMO will be eligible for study.