ABSTRACT
Objective: To observe the effects of total intravenous anesthesia(TIVA)and spontaneous respiration on brain oxygen balance status in patients undergoing brain stem neoplasm resection. Method: Thirty patients,ASA grade Ⅰ-Ⅱ, received endotracheal intubation with spontaneous respiration and TIVA. TIVA was maintained with intravenous 0.2% lidocaine 2-3mg?kg~(-1). h~(-1),0.4% propofol 4-6mg?kg~(-1),h~(-1)and 1% ketamine 1-1.5mg?kg~(-1). h~(-1). Arterial and jugular bulb blood samples were taken before and after induction,sawing skull and removing trmor seperately to analyse blood gas. According to Fick principle, the level of CaO_2,CjvO_2 and C (a-jv)O_2 were calculated. Result:The hymodynamics, SaO_2 and CaO_2 remained stable during whole procedure. In comparison with the baselines. respiratory rate, minute volume, arterial blood pH and C(a-jv)O_2 were decreased, and PaCO_2.SjvO_2, and CjvO_2 were increased significantly (P