A comparison of target controlled versus manually controlled infusion of propofol in elderly patients

Abstract

To evaluate the impact of anesthesia via target-controlled infusion (TCI) on drug consumption, intraoperative hemodynamic stability and recovery compared with manual-controlled infusion (MCI) in elderly patients. Under the approval of the hospital ethics committee, 60 elderly patients undergoing laparoscopic surgery were randomly allocated by random numbers to either the MCI group (n = 30) or the TCI group (n = 30). The patients in MCI group received an infusion of propofol at 200 ml/h while those in TCI group propofol at an initial plasma concentration of 2.0 µg/ml and titrated upwards by 0.5 µg/ml steps until loss of consciousness. Both groups received an infusion of remifentanil. After intubation, the infusion rate or the target concentration of propofol was titrated to maintain BIS (bispectral index) values between 40 and 60. The infusion of remifentanil was adapted to intraoperative hemodynamics. The doses of propofol and remifentanil were recorded, the hemodynamic parameters and the use of vasoactive drugs collected and the recovery times assessed. The time of loss of consciousness and the time to intubation, the doses of propofol and remifentanil during induction and maintenance were not significantly different between two groups. The times of pump adjustment were less in TCI group versus MCI group [(5.8 ± 2.1) vs (7.8 ± 3.7) times, P < 0.01]. Blood pressure and heart rates were not statistically different at any time point between two groups. There were no significant differences in BIS or the use of vasoactive drugs between two groups. The recovery times were similar for two groups. Although target infusion system is easy to use and requires less time of adjustment, it fails to show added benefit on propofol consumption, hemodynamic stability, anesthesia depth and recovery in elderly patients.