Bevacizumab in Patients With Severe Covid-19

Inclusion Criteria: 1. Age: ≥18 years old, both genders; 2. Confirmed COVID-19 diagnosis (any body fluid tested positive for SARS-CoV-2 nucleic acid by PCR, or positive for SARS-CoV-2 antigen); 3. Respiratory rate ≥ 30 times/min, partial pressure of oxygen (PaO2)/ fraction of inspiration O2 (FiO2)≤ 300mmHg (1mmHg = 0.133kPa), or SpO2 ≤ 93% at rest without supplemental oxygen; 4. Article (3) above is newly appeared within 7 days; 5. Chest radiography or computed tomography shows bilateral chest infiltrates. Exclusion Criteria: 1. Unable to obtain informed consent. 2. Physician with more than 5 years of clinical experience determines that death was inevitable within 24 hours. 3. Severe hepatic dysfunction (Child Pugh score ≥ C, or AST\> 5 times the upper limit); Severe renal dysfunction (estimated glomerular filtration rate ≤ 30mL/ min/1.73 m2) or receive continuous renal replacement therapy, hemodialysis, or peritoneal dialysis. 4. Uncontrolled hypertension (sitting systolic blood pressure\> 160mmHg, or diastolic blood pressure\>100mmHg); previous history of hypertension crisis or hypertensive encephalopathy. 5. Poorly controlled heart diseases, such as NYHA class II and above cardiac insufficiency, unstable angina pectoris, myocardial infarction within 1 year before enrollment, supraventricular or ventricular arrhythmia need treatment or intervention. 6. Severe or above chronic obstructive pulmonary disease (GOLD grade, FEV1/FVC \< 0.5). 7. Hereditary bleeding tendency or coagulopathy; 8. Arterial/venous thromboembolic events within 6 months before enrollment, such as ischemic stroke, transient ischemic attack, deep venous thrombosis, pulmonary embolism, etc. Severe vascular disease (including aneurysms or arterial thrombosis requiring surgery) within 6 months before enrollment. 9. Unhealed wounds, active gastric ulcers or fractures. Gastrointestinal perforation, gastrointestinal fistula, abdominal abscess, visceral fistula formation within 6 months before enrollment. Major surgery (including preoperative Chest biopsy) or major trauma (such as a fracture) within 28 days before enrollment. May have surgery during the trial. 10. Severe, active bleeding such as hemoptysis, gastrointestinal bleeding, central nervous system bleeding, and nosebleeds within 1 month before enrollment. 11. Malignant tumors within 5 years before enrollment. 12. Allergic to bevacizumab or its components. 13. Active tuberculosis, uncontrollable infection, untreated active hepatitis or HIV-positive patients. 14. Pregnant and lactating women and those planning to get pregnant. 15. Participated in other clinical trials, not considered suitable for this study by the researchers.