Objective To assess the effect of different target concentrations of remifentanil on the stability of propofol BIS closed-loop target control infusion and hemodynamics during laparoscopic surgery under general anesthesia.
Methods Eighty-six patients undergoing laparoscopic surgery, 23 males and 63 females, aged 18-60 years, BMI 18-25 kg/m2, ASA physical status Ⅰ or Ⅱ, were randomly divided into three groups. The patients received a plasma target control of remifentanil at 2, 4, 6 ng/ml in group A(n = 28), group B (n = 29), and group C (n = 29) during induction and maintenance of anesthesia. All patients received a plasma target control of propofol at 4 μg/ml during induction of anesthesia. The closed-loop target control of propofol would open when BIS was below 75, and the BIS target value was set to 40-50. MDAPE, Wobble, GS, and the percentage of BIS maintained at 40-50 were calculated. The frequencies of vasoactive drug, the propofol plasma target concentration during closed-loop, and postoperative adverse reactions were recorded.
Results The GS in group C was significantly lower than that in groups A and B (P < 0.05), the ratio of excellent and good BIS in group C was significantly higher than that in groups A and B (P < 0.05), the MDAPE of group C was significantly lower than that in group B (P < 0.05), the Wobble in group C was significantly lower than that in group A (P < 0.05). The propofol plasma target concentration in group A was significantly higher than that in groups B and C (P < 0.05). There was no significant difference in the incidence of postoperative nausea and vomiting among the three groups. No respiratory depression occurred in the three groups.
Conclusion In laparoscopic surgery, the patients with 6 ng/ml target concentration of remifentanil have had the best stability, maintained good anesthetic depth, reduced propofol dosage, and remained stable hemodynamics.