ABSTRACT
Objective To evaluate the feasibility of propofol infusion by a closed-loop system for the titration of anaesthetic in laparoscopic cholecystectomy guided by Bispectral Index ( BIS). Methods Forty patients subjected to laparoscopic cholecystectomy randomly allocated into two groups: the control group with opened-loop titratioin of propofol TCI induced at a target of 4 μg?mL-1 and aintained from 2 to 5 μg?mL-1 and the treatment group with closed-loop titration was performed using a proportional differential algorithm.For both groups,the BIS was set at 45-55.Remifentanil TCI was infused at a target of 4 ng?mL-1 and was maintained according to the situation.The change in medial arterial pressure(MAP),heart rate (HR) and BIS were recorded before anesthesia(t0 ),target BIS of 50(t1 ),at tracheal intubation(t2 ),during incision of skin (t3 ),5 min after the operation(t4 ),at t5 of gallbladder removing and at t6 of skin suturing.The dose of propofol was calculated. Results Haemodynamic data were similar between groups during the induction.But MAP was decreased significantly at t1 ,t3 ,t4 , t5 in the control compared with the treatment group (P<0.05).HR changes a lot at t5 in the control compared with the treatment (P<0.05).Total dose of propofol in the treatment group was statistically lower than that in the controls [(110.10± 8.34) vs (120.55±6.26) mg; (603.20±116.55) vs (759.50±116.37) mg,P<0.05)]. Conclusion Automated titration guided by BIS for propofol infusion is feasible without increase in haemodynamic adverse effects and is of less propofol consumption in the laparoscopic cholecystectomy.