Anticoagulation in Critically Ill Patients With COVID-19 (The IMPACT Trial)

Inclusion Criteria: * Age \>18 years old * COVID-19 positive on (RT-PCR) nasopharyngeal swab, or suspected COVID-19 infection with detectable SARS-CoV-2 IgG or IgM. * Intensive care unit (ICU) patient or non-ICU patient on invasive mechanical ventilation, BiPAP, 100% non-rebreather mask, or high flow oxygen or supplemental oxygen of at least 4 liters per minute nasal cannula. * D dimer level greater than 700 ng/mL (3 times the upper limit of normal). Exclusion Criteria: * Objectively documented deep vein thrombosis or pulmonary embolism * Patients in whom there is very high suspicion for pulmonary embolism and are on full-dose anticoagulation as per the treating physician * Platelets \<30,000 not due to disseminated intravascular coagulation (DIC), based on the International Society of Thrombosis and Haemostasis (ISTH) criteria and American Society of Hematology (ASH) Frequently Asked Questions * Active bleeding that poses a contraindication to therapeutic anticoagulation in the opinion of the investigator. * History of bleeding diathesis (e.g., hemophilia, severe von Willebrand disease, severe thrombocytopathy) * History of intracranial hemorrhage in the last 90 days * History of ischemic stroke in the past 2 weeks * Major neurosurgical procedure in the past 30 days * Cardiothoracic surgery in the past 30 days * Intra-abdominal surgery in the past 30 days * Intracranial malignancy * Patients who require therapeutic anticoagulation for other reasons like atrial fibrillation, deep venous thrombosis, pulmonary embolism, or antiphospholipid syndrome.