The ARCTIC Trial: Aerosolized Inhaled Adenosine Treatment in Patients With Acute Respiratory Distress Syndrome (ARDS) Caused by COVID-19

Inclusion Criteria: * Adult (≥ 18 years old) male and female patients with diagnosed COVID-19 respiratory infection, verified by culture/swab RNA. Impending ARDS respiratory collapse with progressive increasing oxygen requirements, and in line with sub-study as defined below. * Patients intubated within the prior 24 hours. * Hemodynamically stable (not requiring vasopressors or catecholamine agents to support systemic blood pressure; no existing shock defined as BP \< 100 mmHg systolic). * In-place continuous arterial line for blood sampling. Exclusion Criteria: * Younger than 18 years old. * Prisoners * Pregnant women. * Unable to obtain next of kin consent. * End-stage cardiac disease with COVID-19. * Non COVID-related causes of ARDS/respiratory failure, septic shock, or post trauma shock, respiratory failure after blood transfusion or surgery. * Unstable asthma or history of frequent/poorly controlled asthmatic attacks. * Not expected to live more than 6 months due to underlying condition such as cancer.