[Bispectral index monitoring is useful to reduce total amount of propofol and to obtain immediate recovery after propofol anesthesia]

Abstract

Bispectral index (BIS) is a processed EEG parameter for assessment of hypnotic effects of anesthetics. We studied whether BIS monitoring can improve recovery from propofol anesthesia and decrease the total amount of propofol needed. Forty-six patients without hypertension and obesity were studied. In the BIS group (n = 20), propofol infusion rate was adjusted to achieve a target BIS value between 40-60, increasing to 65 during the final 10 min of the surgical procedure. In the control group (n = 19), propofol infusion rate was adjusted based only on standard clinical signs. Compared with the control group, patients in the BIS group required lower propofol infusion rates(4.3 +/- 1.1 vs 4.9 +/- 0.8 mg.kg-1.h-1; P < 0.05), and the total amount of propofol decreased significantly (709 +/- 210 vs 914 +/- 326 mg; P < 0.05). BIS monitoring led to immediate recovery after propofol anesthesia. There were no significant differences in the incidence of intraoperative responses between the two groups. BIS monitoring decreased the total amount of propofol and led to immediate recovery after propofol anesthesia. These findings indicate that the use of BIS monitoring may be useful in controlling the infusion rate of propofol during surgery.