Bispectral Index and Patient State Index During General Anesthesia With Remimazolam

The aim of this study is to compare the bispectral index (BIS) and patient state index (PSI) during general anesthesia using remimazolam. The infusion rate of remimazolam is 6-12mg/kg/h during induction of anesthesia and 1-2mg/kg/h during maintenance of anesthesia. To calculate the fraction, the sum of times when BIS\<60 and PSI \<50 will be divided by the time from the loss of consciousness during induction of anesthesia to fully awake during emergence. We will compare the fraction of BIS \<60 and the fraction of PSI \<50 to find if there is some difference between the two depth of anesthesia monitoring devices during remimazolam anesthesia.