Abstract: Objective To compare the difference of bispectral index (BIS) between intracranial tumor and non-intracranial tumor patients under general anesthesia with the same target-controlled infusion (TCI) propofol and to investigate the feasibility of BIS to monitor the sedation level of intracranial tumor patients under general anesthesia.Methods Twenty-five patients scheduled for elective intracranial tumor resection by under general anesthesia were enrolled in the study, ASA I-Ⅲ. And 25 subjects with spinal tumors were included as controls. We placed BIS sensor on the frontal area. The patients were anesthetized with the same TCI propofol and BIS values were collected before the induction of anesthesia, after incision, craniectomy, dura opening,during tumor resection,hemostasis,spontaneous eye opening. We compared the difference of BIS between intracranial tumor and non-intracranial tumor group. Results At the same Cp,BIS values were not statistically different between intracranial tumor group and non-intracranial tumor group:before induction of anesthesia(93.0±4.2 vs 92.8±4.1);after incision(39.3±7.28 vs 38.6±6.7); craniotomy (39.0±7.2 vs 39.1±6.1); dura opening(37.4±7.1 vs 39.7±7.4); during tumor resection (38.8±8.2 vs 39.9±5.5); hemostasis(39.9±11.0 vs 41.5±5.2); spontaneous eye opening(81.2±5.8 vs 80.8±4.6). Conclusion The BIS values can accurately reflect the actual level of consciousness of intracranial tumor patients under general anesthesia with TCI propofol.

Key words: bispectral index, neurosurgical anesthesia, electroencephalography