Acute Respiratory Distress Syndrome (ARDS) is a form of acute diffuse lung injury caused by various etiologies, which rapidly progresses to acute respiratory failure. It is characterized by a sudden onset and severe clinical course. Globally, ARDS affects approximately 3 million individuals each year, accounting for about 10% of admissions to intensive care units (ICUs). Due to the lack of specific pharmacological therapies, mechanical ventilation remains the mainstay of treatment. Therefore, identifying and analyzing prognostic factors for ARDS patients is of great significance for improving patient outcomes and reducing the incidence of poor prognosis.

Inclusion Criteria:

• Patients with underlying diseases associated with high risk of ARDS, including but not limited to: sepsis, pneumonia, multiple trauma, pulmonary contusion, inhalation injury, massive blood transfusion, other high-risk conditions, or other factors causing excessive respiratory drive.
• Patients meeting the inclusion criteria for a high-risk ARDS population.
• Patients (or legal representatives) who have provided a signed and dated informed consent form.

Exclusion Criteria:

• Age under 18 years.
• HIV infection.
• Known immunodeficiency disorders (e.g., leukemia, common variable immunodeficiency, etc.).
• History of solid organ or bone marrow transplantation.
• Receiving treatment with G-CSF or GM-CSF.
• Patients with a decision to withdraw from active treatment.

Patients identified as high risk for ARDS after ICU admission.