Clinical Research Directory

Inclusion Criteria: * Patients with moderate-to-severe ARDS in the acute exacerbation phase who meet the diagnostic criteria for moderate-to-severe ARDS * Receiving tracheal intubation for mechanical ventilation within 72 hours after an episode of moderate-to-severe ARDS * ARDS onset to randomized grouping within 72 hours (starting at the time of onset documented in the medical record) * Patient volunteers to participate in the study and signs an informed consent form Exclusion Criteria: * Pregnancy or breastfeeding * brain death * Advanced cancer or other terminal disease * History of allergy to Sivelestat Sodium and Dexamethasone * Severe chronic obstructive pulmonary disease * History of severe cardiovascular disease, such as heart failure, uncontrolled coronary artery disease, cardiomyopathy, uncontrolled cardiac arrhythmia, uncontrolled hypertension, or history of heart or cerebral infarction within the past six months * Organ transplant or allogeneic stem cell transplant recipients * Fatal active fungal infections * neuromuscular disease that affects voluntary breathing * Genetic or acquired severe immunodeficiencies such as human immunodeficiency virus (HIV) infection, chronic granulomatous disease, severe combined immunodeficiencies * Patients and/or legal representatives who sign a Do Not Resuscitate (DNR) advance directive, or who abandon treatment * Participating in other clinical trials