SUCCESSFUL USE OF BIVALIRUDIN DURING THE THIRD TRIMESTER OF PREGNANCY WHILE ON EXTRACORPOREAL MEMBRANE OXYGENATION

ABSTRACT

SESSION TITLE Close Critical Care Calls SESSION TYPE Case Reports PRESENTED ON 10/18/2022 1115 am - 1215 pm INTRODUCTION: Heparin is the preferred anticoagulant for use in pregnancy while on extracorporeal membrane oxygenation (ECMO) (1). Alternatives to heparin in this patient population are not well studied as heparin-induced thrombocytopenia is rare in pregnancy. Parenteral non-heparin anticoagulants available in the United States include the direct thrombin inhibitors argatroban and bivalirudin, both of which are utilized in ECMO. Guidelines recommend avoidance of these agents in pregnancy if at all possible (2). Whereas case reports support the safe use of argatroban in pregnancy, to our knowledge, there are no known documented reports of bivalirudin use in this patient population (3). Here we describe the successful use of bivalirudin during pregnancy. CASE PRESENTATION A 25 year old G2P1 was transferred to our institution at 28 weeks gestation for further management of acute hypoxic respiratory failure secondary to COVID-19. On hospital day 2 the patient was urgently placed on venovenous (VV) ECMO for refractory hypoxemia, high dead space with acidosis, and the inability to provide adequate gas exchange and lung protection with mechanical ventilation alone. Following ECMO cannulation with a 25f cannula in the right femoral vein and a 21f cannula in the right internal jugular vein, she was anticoagulated with heparin at a rate of 12 units/kg/hr. This was titrated to target a PTT goal of 60-80 seconds. On ECMO day 2, the TEG demonstrated a markedly hypocoagulable state, and the heparin nomogram called for increasing heparin dosing based on PTT. Given the already high dose of heparin that the patient was on (32.9 units/kg/hr), the decision was made to switch from heparin to bivalirudin to prevent over anticoagulation and reduce bleeding risk. Bivalirudin was titrated to a goal PTT of 50-60 seconds, with an initial rate of 0.15 mg/kg/hr (dose range 0.15-0.22 mg/kg/hr). Therapy was continued and on ECMO day 11, at 29w6d the patient delivered via cesarean section. Bivalirudin was discontinued 2.5 hours prior to the surgical procedure which resulted with no fetal bleeding complications. The patient was decannulated from ECMO on day 20 and was later discharged from the hospital. The newborn is developing well and meeting age adjusted milestones. DISCUSSION: Bivalirudin was selected based on institutional experience and the pharmacokinetic properties of the drug (half-life of 25 minutes) as we considered a situation where an emergent delivery may be indicated. Bivalirudin successfully prevented clotting of the circuit with no maternal or fetal bleeding complications during its use. CONCLUSIONS: Our case report describes a multidisciplinary approach to managing a pregnant patient on ECMO requiring anticoagulation using an alternative medication to heparin. This is the first documented use of bivalirudin in pregnancy. Reference #1 ELSO Guidelines for Cardiopulmonary Extracorporeal Life Support Extracorporeal Life Support Organization, Version 1.4 August 2017. Ann Arbor, MI, USA www.elso.org. Reference #2 Bates SM, Greer IA, Middeldorp S, Veenstra DL, Prabulos AM, Vandvik PO. VTE, thrombophilia, antithrombotic therapy, and pregnancy Antithrombotic Therapy and Prevention of Thrombosis, 9th ed American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012;141(Suppl) e691S–736S Reference #3 Young SK, Al-Mondhiry HA, Vaida SJ, et al. Successful use of argatroban during the third trimester of pregnancy case report and review of the literature. Pharmacotherapy 2008;28 1531–6. DISCLOSURES No relevant relationships by Jacqueline Finger No relevant relationships by Caitlin Gluck No relevant relationships by Cameron Hypes No relevant relationships by John Rathbun