目的探讨不同机械通气模式对于老年腹部手术患者细胞因子的影响。方法 72例择期进行腹部手术全麻机械通气的老年患者(年龄>65岁)分为6组,每组12例。A组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+auto-flow模式;B组:VCV(Vt 6 m L/kg)+PEEP 8 mm...目的探讨不同机械通气模式对于老年腹部手术患者细胞因子的影响。方法 72例择期进行腹部手术全麻机械通气的老年患者(年龄>65岁)分为6组,每组12例。A组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+auto-flow模式;B组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+const-flow模式;C组:VCV(Vt 6 m L/kg)+PEEP 12 mm Hg+auto-flow模式;D组:VCV(Vt 6 m L/kg)+PEEP 12mm Hg+const-flow模式;E组:VCV(Vt 10 m L/kg)+auto-flow模式;F组:VCV(Vt 10 m L/kg)+const-flow模式。6组患者全身麻醉气管插管后,均予以VCV(Vt 6 m L/kg)+const-flow模式通气60 min,再按分组的通气模式进行通气,总通气时间大于5 h。在通气1 h及5 h两个时间点,抽取静脉血和支气管肺泡灌洗液检测IL-8、IL-10、MMP-9、SP-A以及SF浓度。结果大潮气量组(E、F两组)较小潮气量四组(A、B、C、D四组)通气5 h后,血与BALF中测定的IL-8、MMP-9浓度以及血中测定的SP-A、SF浓度明显升高(P<0.05),血与BALF中测定的IL-10浓度以及BALF中测定的SP-A浓度明显降低(P<0.05)。通气5 h后F组较E组,血及BALF中IL-8以及MMP-9、血SF、血SP-A更高(P<0.05),而BALF中SP-A则更低(P<0.05)。结论 (1)大潮气量机械通气较小潮气量机械通气而言,更有利于促进IL-8、MMP-9、SF的分泌,抑制IL-10的释放,BALF中SP-A下降,血中SP-A升高,进一步加剧了VILI的程度。(2)就老年(年龄>65岁)腹部手术患者而言,围手术期以VCV(Vt6 m L/kg)+PEEP 12 mm Hg+auto-flow模式机械通气较其他五种通气模式,更有利于减轻肺组织急性炎症反应及氧化应激反应的激活,减轻机械通气所致生物伤,从而减轻VILI的程度。展开更多
The accuracy of nucleation parameter is a critical factor in the simulation of microstructural evolution during dynamic recrystallization(DRX).Based on the flow stress curve under hot deformation conditions,a new appr...The accuracy of nucleation parameter is a critical factor in the simulation of microstructural evolution during dynamic recrystallization(DRX).Based on the flow stress curve under hot deformation conditions,a new approach is proposed to identify the nucleation parameter during DRX.In this approach,a cellular automaton(CA) model is applied to quantitatively simulate the microstructural evolution and flow stress during hot deformation;and adaptive response surface method(ARSM) is applied as optimization model to provide input parameters to CA model and evaluate the outputs of the latter.By taking an oxygen-free high-conductivity(OFHC) copper as an example,the good agreement between the simulation results and the experimental observations demonstrates the availability of the proposed method.展开更多
文摘目的探讨不同机械通气模式对于老年腹部手术患者细胞因子的影响。方法 72例择期进行腹部手术全麻机械通气的老年患者(年龄>65岁)分为6组,每组12例。A组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+auto-flow模式;B组:VCV(Vt 6 m L/kg)+PEEP 8 mm Hg+const-flow模式;C组:VCV(Vt 6 m L/kg)+PEEP 12 mm Hg+auto-flow模式;D组:VCV(Vt 6 m L/kg)+PEEP 12mm Hg+const-flow模式;E组:VCV(Vt 10 m L/kg)+auto-flow模式;F组:VCV(Vt 10 m L/kg)+const-flow模式。6组患者全身麻醉气管插管后,均予以VCV(Vt 6 m L/kg)+const-flow模式通气60 min,再按分组的通气模式进行通气,总通气时间大于5 h。在通气1 h及5 h两个时间点,抽取静脉血和支气管肺泡灌洗液检测IL-8、IL-10、MMP-9、SP-A以及SF浓度。结果大潮气量组(E、F两组)较小潮气量四组(A、B、C、D四组)通气5 h后,血与BALF中测定的IL-8、MMP-9浓度以及血中测定的SP-A、SF浓度明显升高(P<0.05),血与BALF中测定的IL-10浓度以及BALF中测定的SP-A浓度明显降低(P<0.05)。通气5 h后F组较E组,血及BALF中IL-8以及MMP-9、血SF、血SP-A更高(P<0.05),而BALF中SP-A则更低(P<0.05)。结论 (1)大潮气量机械通气较小潮气量机械通气而言,更有利于促进IL-8、MMP-9、SF的分泌,抑制IL-10的释放,BALF中SP-A下降,血中SP-A升高,进一步加剧了VILI的程度。(2)就老年(年龄>65岁)腹部手术患者而言,围手术期以VCV(Vt6 m L/kg)+PEEP 12 mm Hg+auto-flow模式机械通气较其他五种通气模式,更有利于减轻肺组织急性炎症反应及氧化应激反应的激活,减轻机械通气所致生物伤,从而减轻VILI的程度。
基金Project(2006CB705401) supported by the National Basic Research Program of China
文摘The accuracy of nucleation parameter is a critical factor in the simulation of microstructural evolution during dynamic recrystallization(DRX).Based on the flow stress curve under hot deformation conditions,a new approach is proposed to identify the nucleation parameter during DRX.In this approach,a cellular automaton(CA) model is applied to quantitatively simulate the microstructural evolution and flow stress during hot deformation;and adaptive response surface method(ARSM) is applied as optimization model to provide input parameters to CA model and evaluate the outputs of the latter.By taking an oxygen-free high-conductivity(OFHC) copper as an example,the good agreement between the simulation results and the experimental observations demonstrates the availability of the proposed method.
