[1] Inha Univ, Div Crit Care Med, Dept Hosp Med, Coll Med, Incheon, South Korea
[2] Inha Univ, Div Gastroenterol, Dept Internal Med, Coll Med, 27 Inhang Ro, Incheon 22332, South Korea
[3] Chungbuk Natl Univ, Div Gastroenterol, Dept Internal Med, Coll Med, Cheongju, South Korea
[4] Inha Univ, Dept Anesthesiol & Pain Med, Coll Med, Incheon, South Korea