Clinical Research Directory

\# Inclusion Criteria: \- Acute Respiratory Failure group Among patients admitted to the internal medicine intensive care unit at Samsung Seoul Hospital, if all of the following conditions are met: 1\) Age 18 or older 2) Patients who require treatment with high flow nasal cannula (HFNC), non-invasive ventilation (NIV (BIPAP or CPAP)), or mechanical ventilation (MV) due to acute respiratory failure. \- control group For comparative analysis, among patients admitted to the internal medicine intensive care unit at Samsung Seoul Hospital who meet all of the following conditions, they are registered as a control group with the consent of the subjects and undergo the same research procedure. 1. Age 18 or older 2. Patients who do not require high flow nasal cannula (HFNC), non-invasive ventilation (NIV (BIPAP or CPAP)), or mechanical ventilation (MV) treatment * Exclusion Criteria: If any of the following criteria applies, you will not be permitted to participate in this clinical trial. 1. Patients 48 hours after oxygen treatment (HFNC, NIV (BIPAP or CPAP), MV) 2. Patients transferred from another hospital 3. Patients with limitations in treatment