A new sedation technique with propofol during spinal anesthesia

: We compared our new sedation technique with propofol during spinal anesthesia (Group B, n = 50) with a previously described method by Mackenzie et al. (Group A, n = 20). In Group A, propofol was started at a rate of 6 mg.kg-1.h-1 for 10 minutes, followed by continuous infusion at a rate of 4 mg.kg-1.h-1 till the end of surgery. In Group B, propofol 0.4 mg.kg-1 was administered by a bolus injection at the beginning. One-hundred and fifty minutes after the first injection, propofol 0.2 mg.kg-1 was added. The third dose of 0.1 mg.kg-1 of propofol was given 150 seconds after the second dose, followed by continuous infusion at a rate of 4 mg.kg-1.h-1 till the end of surgery. When adequate sedation was not obtained in Group B, propofol 0.1 mg.kg-1 was added by bolus fashion occasionally. In Group A, it took 9 min. 29 sec. to complete adequate sedation assessed by Mackenzie and Grant's sedation score. On the other hand, in Group B, it was 7 min. 27 sec. (P < 0.05 compared with Group A). There was neither excitation nor movement during sedation in Group B, while 5 patients experienced such events in Group A. The blood concentrations of propofol in Group B was 0.946 +/- 0.076 microgram.ml-1 and 0.693 +/- 0.136 microgram.ml-1 at 5 minutes and 10 minutes after the beginning of propofol, respectively. These values were significantly lower than those reported by Kugimiya. Our newly developed method for sedation with propofol during spinal anesthesia would be safer and more effective than that previously described by Mackenzie et al.