The effect of monitoringanesthetic depth on the intraoperative anesthetic dose and postoperative recovery of gerontal patients after general anesthesia

Abstract

Objective To explore the effect of anesthetic depth regulated by A-line ARX-index (AAI) and BIS on the intraoperative anesthetic dose and postoperative recovery of gerontal patients suffering total knee replacement surgery under general anesthesia. Methods Sixty old patients undergoing total knee replacement surgery, aged 65-75 y, weighing 45-85 kg, ASA physical statusⅠor Ⅱwere divided into group AAI, group BIS and group contract (group CON)(n=20) using the random digits table method. At 1 d before and 1, 3, 5, 7 d after operation, cognitive function was assessed by mini-mental state examination(MMSE) and the scores were recorded. The total drug dosage during general anesthesia, the recovery time extubation time, the observer assessment of sedation(OAA/S) scale and VAS were also recorded. Results Compared with group CON[propofol(810±17) mg, remifentanil(1.26±0.07) mg], both the propofol dosage[group AAI(450±19), group BIS(500±18) mg] and the remifentanil dosage[group AAI(0.78±0.07) mg, group BIS(0.80±0.08) mg] were less(P 0.05). There was no significant differences among three groups in the MMSE scores at 1 d before and 1, 3, 5, 7 d after operation(P>0.05). Conclusions Application of anesthetic depth monitoring can reduce the dosage of anesthetic, shorten the awakening time and extubation time, while has no significant effect on the MMSE. Key words: A-line ARX-index; Bispectral index; Anesthetic depth; Gerontisml; Total knee replacement; Postoperative cognitive dysfunction