Acute respiratory distress syndrome (ARDS) is a condition associated with hypoxemia due to noncardiogenic causes and results in high mortality. However, the epidemiology and treatment strategy for ARDS may have changed significantly due to the accumulation of a large body of knowledge, following the two-year pandemic of the novel coronavirus (SARS-CoV-2) of which the primary manifestation is ARDS. To improve the quality of ICU care that patients receive after admission to the ICU, a variety of academic societies, including the Japanese Society of Intensive Care Medicine and the Society of Critical Care Medicine, are currently developing evidence-based guidelines and consensus guidelines and statements regarding ABCDEF bundles, nutritional therapy, ICU diary. The ABCDEF bundle, nutritional therapy, and ICU diary have been developed and are being promoted for implementation in hospitals around the world. The implementation of evidence-based ICU care is strongly recommended, especially for patients with acute respiratory distress syndrome who frequently require ventilators to maintain their lives, because their patient outcomes are worse than those who were admitted to ICU with other causes. However, there is still little evidence on how the quality of ICU care (compliance rate) correlates with patient prognosis and outcomes, and there are currently no clear goals or indicators for the ICU care we should develop. This study aims to investigate the epidemiology and treatments given to the patients and evaluate the implementation of evidence-based ICU care and its association with the outcomes of patients with acute respiratory distress syndrome admitted to the ICU. The contents of mechanical ventilation settings, respiratory conditions, and the evidence-based ICU care, such as analgesia, sedation, rehabilitation, and nutrition, given to the patients will be collected in a daily basis. Aim 1: Epidemiology Aim 2: Treatments Aim 3: Evidence-based ICU care Aim 4: ARDS related Post Intensive Care Syndrome