Effects of infusion methods of propofol on quality of sedation and ease of sedation control during gynecological laparotomy under spinal anesthesia

: Twenty patients were prospectively and randomly studied to investigate effects of infusion methods of propofol on quality of sedation and ease of sedation control during gynecological laparotomy under spinal anesthesia. After establishment of spinal anesthesia, patients were randomly assigned to one of the following two groups, i.e. conventional continuous infusion group (Cont group) and target-controlled infusion group (TCI group). In the Cont group, propofol was started at a rate of 6 mg.kg-1.hr-1 until response to command disappeared. In the TCI group, the initial target concentration of propofol was set at 1.2 micrograms.ml-1 until response to command disappeared. Thereafter infusion rate or target concentration was adjusted to maintain Mackenzie's score at 3 or 4. Predicted concentration of propofol was 1.2 +/- 0.01 micrograms.ml-1 at induction of sedation and 1.2 +/- 0.11 micrograms.ml-1 during stable sedation in the TCI group. Satisfaction VAS, anxiety VAS, discomfort VAS, sedation score and times of changing infusion condition were similar in both groups. Total dose of propofol was significantly less in the TCI group. In conclusion, quality of sedation and ease of control of sedation were comparable in both groups and continuous infusion method is simple.