[1] Severance Hospital,Division of Pulmonology, Department of Internal Medicine
[2] Yonsei University College of Medicine,Daejeon Regional Emergency Center
[3] Chungnam National University Hospital,Division of Intensive Care Units, Department of Nursing Care
[4] Chungnam National University Hospital,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine
[5] Chungnam National University Hospital,Department of Emergency Medicine
[6] Daejeon Sun-Hospital,Department of Emergency Medicine
[7] Chungnam National University Hospital,undefined