Youn-Jung Kim1, Won Young Kim2, Gi-Byoung Nam3. 1. Department of Emergency Medicine, Ulsan University College of Medicine, Asan Medical Center, Seoul, Republic of Korea. 2. Department of Emergency Medicine, Ulsan University College of Medicine, Asan Medical Center, Seoul, Republic of Korea. Electronic address: wonpia73@naver.com. 3. Department of Internal Medicine, Ulsan University College of Medicine, Asan Medical Center, Seoul, Republic of Korea.