Comparison of anesthesia effects between closed-loop and open-loop target controlled infusion of propofol using the bispectral index in abdominal surgery.

Objectives Bispectral index (BIS) can reflect the depth of propofol sedation. This study aims to compare the anesthetic satisfaction, anesthetic dose, and hemodynamic changes between closed-loop target controlled infusion (CLTCI) and open-loop target controlled infusion (OLTCI) during abdominal surgery. Methods From December 2016 to December 2018, 70 patients undergoing abdominal surgery under general anesthesia were selected in Beijing Hospital, including 51 males and 19 females, at the age from 49 to 65 years old. They were classified as grade I-II by the American Society of anesthesiologists (ASA) and were randomly divided into the CLTCI group and the OLTCI group (n=35). The CLTCI group received propofol CLTCI, and the target BIS value was set between 45 to 55; in the OLTCI group, the plasma target concentration was adjusted to maintain the BIS value between 40 to 60. Both groups were given remifentanil by target controlled infusion, and the plasma target concentration was 6.0 ng/mL. The percentages of adequate anesthesia time, deep anesthesia time, and light anesthesia time were calculated. The total induction dose of propofol, continuous infusion dose of propofol, predicted target propofol concentration of effect chamber, and continuous infusion dose of remifentanil were calculated. The times of automatic adjustment of propofol concentration in closed-loop system and manual adjustment of propofol concentration in the OLTCI group were recorded. Hemodynamic indexes were recorded, and the percentage of target mean arterial pressure (MAP) maintenance time and target heart rate (HR) maintenance time were calculated. Anesthesia time, operation time, recovery time, and extubation time were compared between the 2 groups. Results In the induction stage, the percentage of adequate anesthesia time in the CLTCI group was higher than that in the OLTCI group, and the percentage of deep anesthesia time in the CLTCI group was significantly lower than that in the OLTCI group (both P 0.05). There were no significant differences in the percentages of target MAP maintenance time and target HR maintenance time between the 2 groups (both P>0.05). There was no intraoperative awareness in both groups, and there were no significant differences in operation time and anesthesia time between the 2 groups (both P>0.05). Conclusions Compared with propofol OLTCI, anesthesia with propofol CLTCI under BIS guidance can maintain a more appropriate depth of anesthesia sedation and more stable hemodynamics.