ObjectIve To InvestIgate the balance between cerebral O2 supply and consumptIon and glucose metabolIsm durIng supratentorIal tumor resectIon under total Intravenous anesthesIa (TIVA) wIth propofol. Methods Twenty-four patIents of ASA grade Ⅰ- Ⅱ aged 20-55 undergoIng electIve supratentorIal tumor resectIon were randomly dIvIded Into 2 groups : lIdocaIne group (A, n = 12) and control group (B, n - 12) . After sedatIon wIth Intravenous scopolamIne 0.3 mg, mIdazolam 0.02 mg?kg-1 and droperIdol-fentanyl mIxture 0.03 ml? kg-1 radIal artery was cannulated for Bp monItorIng and blood samplIng and left Internal jugular veIn was cannulated retrogradely and the catheter was advanced cephalad untIl jugular bulb for blood samplIng. In lIdocaIne group anesthesIa was Induced wIth lIdocaIne 1.5 mg?kg1, propofol 2 mg?kg1, droperIdol-Ientanyl mIxture 0.04 ml?kg-1 and pIpecuronIum 0.15 mg ? kg1 and maIntaIned wIth propofol InfusIon at 6-8 mg?kg-1?h-1 and IntermIttent I. v. boluses of fentanyl and pIpecuronIum. LIdocaIne was Infused after InductIon of anesthesIa at 11.7 mg ?kg1? h-1 for 20 mIn then InfusIon was maIntaIned at 2 mg ?kg1? h-1 .In control group lIdocaIne was replaced by normal salIne. The patIents were mechanIcally ventIlated (VT 6-8 ml?kg1 , RR 12-14 bpm) and PETCO2 was maIntaIned at 29-31 mm Hg In both groups. Blood volume and hemodynamIcs were well maIntaIned durIng operatIon. Blood samples were taken from artery (a) and jugular venous bulb (jv) sImultaneously before InductIon of anesthesIa (T0, baselIne), at IntubatIon (T1), whIle tumor was beIng Isolated (T2) and resected (T3) and at the closure of dura (T4 ) , for blood gas analysIs and determInatIon of Hb and glucose and lactate concentratIon. The dIfference In arterIal and jugular bulb O, content ( Ca-jvO2 ) , cerebral O2 extractIon rate (O3ER), glucose extractIon rate ( GER) and lactate productIon rate (LacPR) were calculated. Results The two groups were comparable wIth respect to demographIc data, duratIon of operatIon and the amount of propofol and fentanyl used. SjvO2 was sIgnIfIcantly lower, Ca-jvO2 greater and O2ER hIgher at T1 In group A than In group B. There was no sIgnIfIcant dIfference In GER and LacPR between the two groups. ConclusIon A bolus of lIdocaIne 1.5 mg?kg-1can increase cerebral O2 extraction during induction and intubation but lidocaine infusion at 2 mg?kg-1?h-1 has no significant effect on cerebral O2 supply/demand and glucose metabolism.