[1] Fukushima Med Univ Hosp, Dept Anesthesiol, 1 Hikarigaoka, Fukushima, Fukushima 9601295, Japan
[2] Tohoku Univ, Sch Med, Dept Anesthesiol & Perioperat Med, 2-1 Seiryo Machi,Aoba Ku, Sendai, Miyagi 9808575, Japan
[3] Shimura Hosp, Dept Anesthesiol, 3-13 Funairi Machi,Naka Ku, Hiroshima, Hiroshima 7300841, Japan
[4] Dokkyo Med Univ, Sch Med, Dept Anesthesiol, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan
[5] Jikei Univ, Sch Med, Dept Anesthesiol, Nishi Shimbashi 3-25-8, Minato, Tokyo 1058461, Japan