Cerebral Bleeding in COVID-19 ARDS Patients on Veno-venous ECMO

Overview

Critically ill patients with severe acute respiratory distress syndrome (ARDS) sometimes require treatment with veno-venous extracorporeal membrane oxygenation (ECMO) to support gas exchange. To prevent clotting of the ECMO circuit, these patients need to be anticoagulated. This protective anticoagulation also leeds to an increased bleeding risk. Most critically ill COVID-19 patients suffer from an ARDS and some require ECMO support. However, the optimal strategy and targets for the anticoagulation of these patients remain uncertain. Studies have shown that COVID-19 is associated with endotheliopathy probably leading to procoagulatory effects. On the other hand, the incidence of bleeding complications associated with this endotheliopathy is not clear and remains to be elucidated. Anticoagulation of COVID-19 patients on ECMO thus poses a challenge for clinicians. The hypothesis of the current project is that COVID-19 patients with ARDS on ECMO exhibit a higher number of bleeding complications compared to historical control patients with non-COVID-19 ARDS requiring ECMO support.

The primary aim of the project is to retrospectively analyze the incidence of bleeding complications (especially cerebral bleedings) in critically ill COVID-19 patients with ARDS requiring ECMO support. The incidences of bleeding will be compared with a historical control cohort of non-COVID-19 patients on ECMO support. The data analysis will be set up within a multicentric, retrospective study involving the University Hospital Zurich (Switzerland), the Medical School Hannover (Germany) and the University Hospital Bonn (Germany). The aim of the multicentric approach is to increase the case load and to improve the validity of the data, which could possibly have therapeutic implications in the future. Aside from demographic and baseline date, mortality and causes of death, comorbidities, the anticoagulation strategy (substance, targets of anticoagulation) and laboratory parameters of the anticoagulation during the bleeding events will be collected. Furthermore, the intensity of the ECMO treatment (blood flow, sweep gas flow, oxygen requirement) during the bleeding events and the catecholamine use during ECMO implantation will be analyzed. To enhance comparability, intensive care specific treatments (proning, sedation and analgesia, COVID-19 targeted therapy) will be collected and analyzed.