Monitoring of anesthetic depth during surgical correction of acquired valvular disorders: single center, randomized trial.OBJECTIVE:  The authors'' primary objective was to test the hypothesis that Cerebral State Index (CSI)-guided control of anesthetic depth might reduce the consumption of anesthetics and shorten the duration of ICU and hospital stays after surgical correction of combined valve disorders. DESIGN:  Single center, randomized trial. SETTING:  City Hospital Number 1 of Arkhangelsk, Russian Federation. PARTICIPANTS:  Fifty adult patients with combined valve disorders requiring surgical correction. INTERVENTIONS:  The patients were randomized into 2 groups. In the CSI group, anesthetic depth was monitored, and the rate of infusion of propofol was titrated to maintain the depth of anesthesia corresponding to a CSI of 40-60. In the control group, the depth of anesthesia was monitored clinically, and the dosage of propofol was administered according to the recommendations of the manufacturer. MEASUREMENTS AND MAIN RESULTS:  All patients received standard perioperative monitoring. Consumption of anesthetics and length of ICU and hospital stays were recorded. Preoperative patient characteristics did not differ significantly between the groups. In the CSI group, average intraoperative doses of midazolam and propofol were reduced by 41% and 19%, respectively (p<0.01). Maintenance of anesthesia guided by CSI shortened the time until fit for ICU discharge by 50% and reduced the lengths of ICU and postoperative hospital stays by 35% and 25%, respectively (p< 0.05). CONCLUSIONS:  Monitoring of anesthetic depth reduces the requirements for midazolam and propofol, resulting in a faster recovery and a shorter postoperative ICU and hospital stay after surgical correction of combined valve disorders.