Abstract: Relations between the maintenance concentration of desflurane, BIS, SEF and hemodynamics were evaluated in order to select a suitable inhalation concentration in neurosurgery. Thirty-six patients, ASA gradeⅠ to Ⅱ, undergoing neurosurgery were divided into three groups: 0.7 MAC(4.2 %), 1.0 MAC(6.0%)and 1.3 MAC(7.8%)with 12 cases each. MAP, HR, BIS and SEF were measured before induction,after induction, before inhalation at the predetermined MAC at maintenance 30, 60, 90, 120, 150, 180 min, stopping inhalation, extubation, opening eyes, following commands and oriential recovery, respectively. Desflurane inhalation concentrations had good dose-relationship with BIS and SEF. Hemodynamics was stable in 1.0 MAC group with faster recovery. 1.0 MAC of desflurane anesthesia is suitable for neurosurgery.

Key words: neurosurgery, desflurane, BIS, SEF