ABSTRACT
Introduction: Anticoagulation strategies for extracorporeal membrane oxygenation(ECMO) support in COVID-19 patients remains controversial. This study aims to present our experience with anticoagulation management and monitoring strategies including bleeding complications during ECMO support. Methods: Retrospectively, we reviewed charts of twelve patients supported with ECMO for COVID-19 from March 2020 to June 2021. Of these, eight patients with veno-venous(VV) ECMO received intravenous(IV) heparin anticoagulation and four with veno-arterial-venous(VAV) ECMO received IV Bivalirudin. Therapeutic partial thromboplastin time(PTT) goal was 50-70seconds in both groups. Results: Average age was 52 years with nine males. All patients had elevated D-dimer level before and during ECMO support. Mean time on ECMO support was 800.3 hours. Overall, therapeutic PTT was achieved in 38% with significant outcomes in Bivalirudin when compared to Heparin group [Heparin:33%(24-49%);Bivalirudin:51%(24-92%), P<0.00001]. Number of patients remained sub-therapeutic (PTT<50s) was 60% [Heparin:63%;Bivalirudin:48.2%], and supra-therapeutic (PTT>70s) was 2% [Heparin:3%;Bivalirudin:0.9%]. In heparin group, major bleeding complications included cerebral in 4, oropharyngeal in 2, and psoas hematoma in 2 patients. Whereas, in Bivalirudin group, only one patient experienced postoperative anemia from acute blood loss. Overall, six died in hospital [Heparin:5patients;Bivalirudin:1patient];two discharged to another hospital for lung transplant [Heparin:0patient;Bivalirudin:2patients, 1 died before listing];three discharged to home alive [Heparin:3patients;Bivalirudin:0patient], and one still remains in the hospital [Heparin:0patient;Bivalirudin:1patient]. Conclusion: Although results are promising for Bivalirudin in terms of lesser hemorrhagic complications and reduced mortality, smaller sample size may have attenuated the findings. Future studies are warranted.
ABSTRACT
Background: Increased rate of thrombotic events have been described in severe COVID-19 disease leading to liberal anticoagulation strategies in patients requiring ECMO support, which might be associated to increased risk of hemorrhagic complications. We present our experience with a conservative anticoagulation approach. Objectives and Methods: Data of eight COVID-19 patients requiring veno-venous (VV) ECMO support between 3/1-8/20/20 was retrospectively analyzed. All patients received anticoagulation with IV heparin with therapeutic target PTT 50-70 seconds. Primary goal was incidence of major hemorrhagic complications, and secondary goals to determine relationship to anticoagulation range, and patient clinical outcome. Results: Mean age was 52 years (36-62). Six (75%) patients were male. Patients received ECMO support for 25 days (10-39). Therapeutic anticoagulation range was achieved 33% (24-49%) of the time, while patients remained sub-therapeutic (PTT<50") 63%, and supratherapeutic (PTT>70") 3% of the time. INR was normal (<1.2) in all patients, and thrombocytopenia (platelet count < 100,000) was observed in 3 patients (37.5%). Major bleeding complications included cerebral in 4 (50%), oro-pharyngeal in 2 (25%), and spontaneous psoas hematoma in 2 (25%) patients. No clear correlation was observed between supratherapeutic anticoagulation and development of hemorrhagic complications. Seven ECMO circuits were exchanged in 6 patients at 13.5 days (9-19). Four (50%) patients were decannulated, and 3 (37.5%) discharged from the hospital alive. Conclusions: Conservative anticoagulation strategies during V-V ECMO support for COVID-19 led to high rate of ECMO circuit exchange but did not prevent hemorrhagic complications. Additional risk factors for bleeding should be considered in these patients.