Anticoagulation Management in Severe Coronavirus Disease 2019 Patients on Extracorporeal Membrane Oxygenation.

To explore special coagulation characteristics and anticoagulation management in extracorporeal membrane oxygenation (ECMO)-assisted patients with coronavirus disease 2019 (COVID-19). Single-center, retrospective observation of a series of patients. Laboratory-confirmed severe COVID-19 patients who received venovenous ECMO support from January 20-May 20, 2020. This study analyzed the anticoagulation management and monitoring strategies, bleeding complications, and thrombotic events during ECMO support. Eight of 667 confirmed COVID-19 patients received venovenous ECMO and had an elevated D-dimer level before and during ECMO support. An ECMO circuit pack (oxygenator and tubing) was replaced a total of 13 times in all 8 patients, and coagulation-related complications included oxygenator thrombosis (7/8), tracheal hemorrhage (5/8), oronasal hemorrhage (3/8), thoracic hemorrhage (3/8), bleeding at puncture sites (4/8), and cannulation site hemorrhage (2/8). Hypercoagulability and secondary hyperfibrinolysis during ECMO support in COVID-19 patients are common and possibly increase the propensity for thrombotic events and failure of the oxygenator. Currently, there is not enough evidence to support a more aggressive anticoagulation strategy.

Guo Z ，Sun L ，Li B ，Tian R ，Zhang X ，Zhang Z ，Clifford SP ，Liu Y ，Huang J ，Li X ... -  《-》

Bivalirudin for Maintenance Anticoagulation During Venovenous Extracorporeal Membrane Oxygenation for COVID-19.

In its severe manifestation, coronavirus disease 2019 (COVID-19) compromises oxygenation in a manner that is refractory to maximal conventional support and requires escalation to extracorporeal membrane oxygenation (ECMO). Maintaining ECMO support for extended durations requires a delicately balanced anticoagulation strategy to maintain circuit viability by preventing thrombus deposition while avoiding excessive anticoagulation yielding hemorrhage-a task that is complicated in COVID-19 secondary to an inherent hypercoagulable state. Bivalirudin, a member of the direct thrombin inhibitor drug class, offers potential advantages during ECMO, including to its ability to exert its effect by directly attaching to and inhibiting freely circulating and fibrin-bound thrombin. Herein, the successful use of an anticoagulation strategy using the off-label use of a continuous infusion of bivalirudin in a case of severe hypoxemic and hypercarbic respiratory failure caused by COVID-19 requiring venovenous ECMO is reported. Importantly, therapeutic anticoagulation intensity was achieved rapidly with stable pharmacokinetics, and there was no need for any circuit interventions throughout the patient's 27-day ECMO course. In COVID-19, bivalirudin offers a potential option for maintaining systemic anticoagulation during ECMO in a manner that may mitigate the prothrombotic nature of the underlying pathophysiologic state.

Seelhammer TG ，Rowse P ，Yalamuri S 《-》

Venovenous Extracorporeal Membrane Oxygenation With Prophylactic Subcutaneous Anticoagulation Only: An Observational Study in More Than 60 Patients.

Extracorporeal lung support and therapeutic anticoagulation are dogmatically linked for most clinicians in fear of clotting of the extracorporeal circuit. In the last decade, however, we have learned that bleeding complications in the course of extracorporeal membrane oxygenation (ECMO) therapy are common and not occasionally limiting or fatal. Even though international guidelines lowered the PTT-target values, ECMO therapy without anticoagulation has only been reported sporadically in case reports heretofore. This monocentric, observational study was designed to evaluate a protocol for venovenous ECMO therapy without additional anticoagulation. Patients without former thrombotic events solely received thrombosis prophylaxis with 40 mg subcutaneous enoxaparin per day like every critical care patient. After approval by the local ethics committee (Albert-Ludwigs-University Freiburg ethics committee, EK 513/14) all consecutive patients treated with venovenous ECMO therapy since introduction of the protocol have been identified. Digital charts of the patients have been evaluated with special regard to bleeding and thrombotic or embolic events or breakdown of the extracorporeal circuit. Sixty-one patients received venovenous ECMO therapy with prophylactic subcutaneous enoxaparin only. Median duration of ECMO therapy was 7 days (2-32). Overall 560 ECMO days have been observed. No system exchange because of thrombotic occlusion was necessary within the permitted 5 days run time of the centrifugal pump. Overall we identified thrombotic complications in four patients. In three of them centrifugal pump after a runtime of more than 5 days unexpectedly stopped completely because of thrombotic occlusion. In all cases pump exchange was performed promptly and patients did not incur hypoxic deficit. One other patient received substitution of blood products and coagulation factor concentrates because of severe bleeding and sustained myocardial infarction the day after. Only 18% of patients presented with essential clinical bleeding after 7 days of therapy. No fatal bleeding event and no intracranial hemorrhage was observed. Patients required only a third of blood product transfusion compared to published data. Venovenous ECMO therapy with prophylactic anticoagulation only was feasible in this study. It was not associated with an increased rate of system exchanges compared to regimes with therapeutic anticoagulation in registry data. It provides the potential to relevantly decrease the incidence of severe bleeding events and blood transfusion requirements. The apodictic adherence to anticoagulation in therapeutic dosage should be critically scrutinized in every patient.

Krueger K ，Schmutz A ，Zieger B ，Kalbhenn J ... -  《-》

Anticoagulation Practices during Venovenous Extracorporeal Membrane Oxygenation for Respiratory Failure. A Systematic Review.

Sklar MC ，Sy E ，Lequier L ，Fan E ，Kanji HD ... -  《-》

Venous Thromboembolism Events Following Venovenous Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Syndrome Coronavirus 2 Based on CT Scans.

Parzy G ，Daviet F ，Puech B ，Sylvestre A ，Guervilly C ，Porto A ，Hraiech S ，Chaumoitre K ，Papazian L ，Forel JM ... -  《-》