Chien-Hsun Chen1, Cheng-Yu Chen1, Yi-Jer Hsieh2. 1. Department of Anesthesiology, Changhua Christian Hospital, No. 135, Nanxiao St., Changhua City, Changhua County 50006, Taiwan. 2. Department of Anesthesiology, Changhua Christian Hospital, No. 135, Nanxiao St., Changhua City, Changhua County 50006, Taiwan. Electronic address: 173406@cch.org.tw.