Systemic fibrinolysis for acute pulmonary embolism complicating acute respiratory distress syndrome in severe COVID-19: a case series.

A peculiar form of coagulopathy develops in patients hospitalized with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with elevations in D-dimer levels (parallel with a rise in markers of inflammation), alterations in clotting times, and thrombocytopenia. Consequently, a high incidence of venous thrombo-embolism (VTE) as well as of pulmonary embolism (PE) has been reported, and linked to increased mortality, in both Chinese and European cohorts. Clinically, this coagulation imbalance seems different from the classical disseminated intravascular coagulation with a bleeding diathesis, and results in a very high incidence of thrombotic and thrombo-embolic events with, prominently, VTE/PE of variable severity. We hereby report a retrospective case series of four patients needing mechanical ventilation for SARS-CoV-2 infection, who were diagnosed with high-risk PE and underwent systemic fibrinolysis with full-dose alteplase, with rapid haemodynamic and respiratory success in three of them. Figures 1 and 2, as well as their legends, report the most relevant clinical characteristics. Detailed descriptions of the four cases appear in the Supplementary material online. The described patients developed sudden haemodynamic instability, and the diagnosis of PE was made with bedside echocardiography, which showed either direct (‘thrombus in transit’, two patients) or indirect (right ventricular strain) signs of PE in all patients. Three cases had been treated with anticoagulants before PE: one case even suffered PE while on sodium heparin, one while on a full, weight-adjusted dose enoxaparin, and the third one 2 days after sodium heparin full anticoagulation was