Abstract
The aim of this study was to examine the effects of different infusion doses of remifentanil on mean arterial pressure (MAP) , heart rate (HR) and electroencephalographic bispectral index (BIS) . Twenty-seven patients who underwent total hysterectomy were studied. They were anesthetized with sevoflurane (end-tidal concentration of 1.0%) combined with a continuous infusion of remifentanil at 0.25 (L group) , 0.625 (M group) or 1.0μg/kg/min (H group) . MAP, HR and BIS were estimated during the first 50 minutes of surgery. MAP and HR in the M and H groups were lower than those in the L group. There were no significant differences found between the M and H groups. Lowest systolic blood pressure and HR during the study were 78 mmHg and 48/min, respectively. BIS remained unaltered, regardless of the remifentanil dose. A does of this opiate between 0.25 and 1.0μg/kg/min in combination with sevoflurane (1.0%) could be safely used during lower abdominal surgery. However, since no difference was found in MAP, HR and BIS between the M and H groups, the infusion rate should be limited to a maximum of 0.625μg/kg/min.
