1. Department of Emergency Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2. Department of Emergency Medicine, College of Medicine, Kangwon National University, Chuncheon, Korea
3. Department of Emergency Medicine, College of Medicine, Hanyang University, Seoul, Korea
4. Department of Critical Care Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
5. Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
6. Department of Emergency Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea