Thrombotic circuit complications during venovenous extracorporeal membrane oxygenation in COVID-19

Abstract

The novel coronavirus SARS-CoV-2 and the resulting disease COVID-19 causes pulmonary failure including severe courses requiring venovenous extracorporeal membrane oxygenation (V-V ECMO). Coagulopathy is a known complication of COVID-19 leading to thrombotic events including pulmonary embolism. It is unclear if the coagulopathy also increases thrombotic circuit complications of the ECMO. Aim of the present study therefor was to investigate the rate of V-V ECMO complications in COVID-19. We conducted a retrospective registry study including all patients on V-V ECMO treated at our centre between 01/2018 and 04/2020. COVID-19 cases were compared non- COVID-19 cases. All circuit related complications resulting in partial or complete exchange of the extracorporeal system were registered. In total, 66 patients were analysed of which 11 (16.7%) were SARS-CoV-2 positive. The two groups did not differ in clinical parameters including age (COVID-19 59.4 vs. non-COVID-19 58.1 years), gender (36.4% vs. 40%), BMI (27.8 vs. 24.2) and severity of illness as quantified by the RESP Score (1pt. vs 1pt.). 28 days survival was similar in both groups (72.7% vs. 58.2%). While anticoagulation was similar in both groups (p = 0.09), centrifugal pump head thrombosis was more frequent in COVID-19 (9/11 versus 16/55 p < 0.01). Neither the time to first exchange (p = 0.61) nor blood flow at exchange (p = 0.68) did differ in both groups. D-dimer levels prior to the thrombotic events were significantly higher in COVID-19 (mean 15.48 vs 26.59, p = 0.01). The SARS-CoV-2 induced infection is associated with higher rates of thrombotic events of the extracorporeal system during V-V ECMO therapy.

Keywords: COVID-19; Pump head thrombosis; Thrombotic complications; V-V ECMO.

Fig. 1

Thrombotic complications in V-V ECMO circuits. a Number of exchanges due to thrombus formation in different parts of the extracorporeal circuit. b Probability of centrifugal pump exchange due to pump head thrombosis

Fig. 2

Laboratory findings during the exchange of parts or the whole venovenous extracorporeal membrane oxygenation circuit. a D-Dimers levels prior to the exchange, laboratory capped value at 35.2 mg/l. b Anticoagulation target prior to the exchange. c Last measured activated partial thromboplastin time (aPTT) prior to the exchange. d aPTT 24 h prior to the exchange. e aPTT 48 h prior to the exchange