Coronavirus Disease (COVID-19) is characterized by a hypercoagulable state, sometimes difficult to be managed with heparin. Bivalirudin, a member of the direct thrombin inhibitor drug class, offers potential advantages compared to heparin, including to its ability to exert its effect by directly attaching to and inhibiting freely circulating and fibrin-bound thrombin.

Investigators have therefore designed this pilot open-label randomized controlled trial to assess if a off-label infusion of bivalirudin may reduce thrombosis, mortality, Intensive Care Unit (ICU) length of stay and increase ventilator free days of patients admitted in ICU for acute respiratory failure due to COVID-19, as compared to first-line treatment with heparin.

Inclusion Criteria:

• ratio between arterial partial pressure to inspired fraction of oxygen (PaO2/FiO2) < 200 mmHg
• age equal or greater of 18 years/old
• detection of coronavirus 2019 at the nasal swab;
• need for endotracheal intubation and invasive mechanical ventilation

Exclusion Criteria:

• known allergies to one of the two investigated drugs
• presence of hematological diseases
• pregnancy
• recent (10 days) surgery
• presence of active bleeding

The individual patients data will be shared only after the publication of the study on an international peer-reviewed journal and on scientific and intelligible proposal

Data will be available after publication on an indexed international and peer-reviewed journal

Access will be allowed after contacting by email the principal investigator, by providing and intelligible and scientific proposal

Investigators and Outcome assessors will not take part in the care of patients. Data will be provide in anonymous form without any indication to the assigned treatment.