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Objective To investigate the effect of dexmedetomidine on the stress responses during wakeup test in patients undergoing cerebral functional area operation performed under propofol combined with remifentanil anesthesia.Methods Thirty-six ASA physical status Ⅰ or Ⅱ patients,undergoing cerebral functional area operation requiring wake-up test,aged 18-60 yr,weighing 50-70kg,were randomly divided into control group (group C) or dexmedetomidine group (group D) with 18 cases in each group.Dexmedetomidine 0.8 μg/kg was infused over 10 min before induction of anesthesia followed by infusion at 0.4 μg·kg-1 · h-1 in group D,while the equal volume of normal saline was infused in group C.Anesthesia was induced with target-controlled infusion of propofol and remifentanil and iv injection of cisatracurium.At 30 min prior to wake-up test,target-controlled infusion of propofol and application of mulscle relaxants were stopped,the target plasma concentration of remifentanil was decreased to 1 ng/ml,and in group D the infusion rate of dexmedetomidine was decreased to 0.1 μg·kg 1· h-1.Anesthesia time and consumption of anesthetics before wake-up test,wake-up time,and development of complications and intraoperative awareness during wake-up test were recorded.At 30 min prior to wake-up test (T1),immediately after wake-up (T2),at 5 min after wake-up (T3),and at 10 min after the anesthetic depth was deepened (T4),HR,mean arterial pressure and BIS value were recorded and blood samples were taken for determination of plasma concentrations of epinephrine (E) and norepinephrine (NE).Results Compared with group C,the consumption of propofol and remifentanil was significantly reduced before wake-up,the incidence of hypertension was decreased during wake-up test,and HR and plasma E and NE concentrations were decreased at each time point (P ＜ 0.05),and no significant difference in mean arterial pressure and BIS value was found in group D (P ＞ 0.05).Tachycardia,restlessness,bucking and awareness were not observed during wake-up test in group D.Conclusion Dexmedetomidine can inhibit the stress responses during wake-up test and raise the quality of wake-up test in patients undergoing cerebral functional area operation performed under propofol combined with remifentanil anesthesia.
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ObjectiveTo investigate the effect of acute normovolemic hemodilution (ANH) on the apoptosis in hippocampal cells induced by global cerebral ischemia-reperfusion (I/R) in rats.Methods Thirty-six healthy 50-60 day old male SD rats weighing 280-320 g were randomly divided into 3 groups ( n =12 each):group sham operation (group S); group global cerebral I/R (group I/R) and group ANH.Global cerebral I/R was produced by 4-vessel technique described by Pulsinelli et al.in groups I/R and ANH.ANH was carried out at 24 h after cauterization of bilateral vertebral arteries,before occlusion of bilateral carotid arteries.Blood was withdrawn from femoral artery until Hct was reduced to 30％ and equal volume of hydroxyethyl starch 130/0.4 sodium chloride was infused into femoral vein simultaneously.Bilateral carotid arteries were blocked for 5 min at 10 min after ANH.The rats were sacrificed at 24 h of reperfusion and their hippocampi were isolated.Apoptosis was detected by flow cytometry.The expression of Apaf-1 mRNA and caspase-3 mRNA was determined by RT-PCR.Results Global cerebral I/R significantly increased apoptosis index and up-regulated Apaf-1 mRNA and caspase-3 mRNA expression in group I/R as compared with group S.ANH significantly attenuated apoptosis and down-regulated Apaf-1 mRNA and caspase-3 mRNA expression in group ANH compared with group I/R.ConclusionANH can reduce hippocampal cell apoptosis induced by cerebral I/R through down-regulation of Apaf-1 and caspase-3 expression in hippocampus.
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Objective To investigate the effect of tea polyphenols on global cerebral ischemia reperfusion injury in rats.Method Forty-five pathogen-free male SD rats weighing 180-220 g were randomly divided into 3 groups( n =15 each):sham operation group (group S),cerebral ischemia reperfusion group (group IR) and tea polyphenols group (group TP).Global cerebral ischemia reperfusion injury was establish by four-vessel occlusion method.At 24 h of reperfusion,five rats were chosen and Evan's blue(EB) was injected iv,and then sacrificed and brain was removed for determination of EB content; another five rats were sacrificed and brain was removed for determination of water content; five rats were chosen for Morris water maze test.Result Compared with group S,EB content and water content in brain tissue were increased in groups IR and 'rP,and escape latency was prolonged,frequency of crossing the original platform was reduced in group IR ( P ＜ 0.05 ).Compared with group IR,EB content and water content in brain tissue were decreased,and escape latency was shortened,frequency of crossing the original platform was increased in group Tp ( P ＜ 0.05).Conclusion Tea polyphenols can attenuate global cerebral ischemia reperfusion injury in rats.