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Objective To investigate the median effective plasma target concentration of propo-fol (Cp50 )needed for lumbar surgery during inhalation-intravenous balanced anesthesia when BIS is 50.Methods Patients aged 40-56 years,scheduled for vertebral pulp ectomy were included.Anesthe-sia were maintained by TCI of propofol,sevoflurane 0.5 MAC,remifentanyl 0.2 μg·kg-1 ·min-1 , and vecuronium 0.08 mg·kg-1 ·h-1 .The target plasma concentration of propofol was initially set at 1.8 μg/ml,and adjusted by the sequential up-and-down methods,based on BIS index.The Cp50 of propofol and its 95% confidence interval (CI)were calculated.Results Twenty-six patients were en-rolled in this study.The median effective plasma target concentration of propofol was 1.61 μg/ml (95%CI 1.52-1.70)μg/ml.Conclusion The Cp50 of propofol needed for maintaining the BIS index of 50 is 1.61 μg/ml during the anesthesia with 0.5 MAC of sevoflurane combined with remifentanyl in lumbar surgery.
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Objective To investigate the effects of electroacupuncture (EA) of different intensities on cerebral energy metabolism in a rat model of global cerebral ischemia-reperfusion (I/R) . Methods Forty male SD rats weighing 200-230 g were randomized into 5 groups ( n = 8 each) : group A sham operation; group B global cerebral I/R and C, D, E groups cerebral I/R+ 5, 3, 1 mA EA. Global cerebral I/R was induced by 4-vessel occlusion technique. Bilateral vertebral arteries were permanently occluded by cauterization.Bilateral common carotid arteries were clamped. When the bilateral pupils were completely dilated, the arteries were unclamped. Baihui,Mingmen and Zusanli were electrically stimulated with 5,3,1 mA (30-50 Hz) for 20 min at 1 h of reperfusion in C, D, E groups. The EA was repeated at 12 h of reperfusion. The animals were sacrificed at 24 h of reperfusion.The activities of Na+ -K+ -ATPase, succinodehydrogenase (SDH) and lactic dehydrogenase(LDH) in brain tissue were measured.Results Cerebral I/R significantly increased LDH activity and decreased Na+ -K+ -ATPase activity in group B as compared with group A. EA with 5 mA significantly decreased LDH activity and increased SDH and Na+ -K+ -ATPase activities in group C compared with group B. Conclusion EA can improve the cerebral energy metabolism in a rat model of global cerebral I/R and it is related to the intensity, which may be the mechanism by which EA reduces the global cerebral I/R injury.
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Objective To investigate the effects of preconditioning with extract of Ginkgo Biloba (EGB) on the tourniquet-induced ischemia-reperfusion (I/R) injury to the limb. Methods Forty ASA Ⅰ or Ⅱ patients aged 17-64 yr weighing 46-72 kg undergoing lower limb operation under combined spinal-epidural anesthesia (CSEA) were randomly divided into 2 groups (n = 20 each) : group A control and group B EGB. CSEA was performed at L2,3 or L3,4 interspace. The height of sensory block was kept below T10. Group B received EGB 0.3 mg/kg in 100 ml normal saline (NS) injected over 20 min via an intravenous line in the forearm as soon as the tourniquet was inflated while control group received plain NS 100 ml without EGB. Venous blood samples were obtained before tourniquet was inflated (To baseline) and at 5, 10, 20 min after tourniquet was released (T_1 , T_2, T_3) for measurement of blood lactate and MDA concentrations and SOD activity. BP (SP, DP) and HR were continuously monitored and recorded at the above time points. Results In control group DP and SOD activity were significantly decreased while blood lactate and MDA concentrations were significantly increased after tourniquet release as compared with the baseline values before tourniquet was inflated. In EGB group there was no significant change in DP, blood lactate and MDA concentrations and SOD activity after tourniquet was released as compared with the baseline. Conclusion Pretreatment with EGB can protect against tourniquet-induced I/R injury to the limb.
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Objective To observe the effect of sevoflurane inhalation anesthesia and propofolsevoflurane combined anesthesia on glucose concentrations.Methods Thirty patients undergoinggeneral anesthesia were randomly divided into two groups with 15 cases each.The patients in group Awere anesthetized with sevoflurane inhalation and those in group B with sevoflurane combined withprovofol.Blood concentration of glucose was measured before operation and at 2 h during surgery.Results The blood glucose concentrations in groups of A and B were significantly increased at 2 h during surgery than those before[(6.23±1.45)mmol/L vs.(4.86±0.85)mmol/L and(6.66±blood glucose between the two groups.Conclusion Both sevoflurane inhalation anesthesia and combined propofol and sevoflurane anesthesia can not inhibit the increase of blood glucose duringoperation.