【作者】 章武强；

【导师】 朱绿绮；

【作者基本信息】 江西医学院 ， 儿科学， 2003， 硕士

【摘要】 目的 探讨感染性休克时新西兰大白兔全身和空肠氧摄取率变化规律和相互关系以及小肠局部可能发生的病理组织学变化。 方法 健康新西兰大白兔15只，随机分成2组：应用大肠杆菌内毒素（E.ColiO111B5）制备兔感染性休克模型，感染性休克组（septic shock SS组，n=10只），对照组（C组，n=5只 注射等量生理盐水）。对照组和感染性休克组,分别做右侧颈外静脉至右心房、股动脉、肠系膜上静脉近端分支插管，稳定一段时间后，密切监测平均动脉压（MAP）的变化，每隔0.5小时抽血行血气分析，总共观测2.5小时，然后观察二组不同时间段血气参数（PH、PO2、PCO2、BE、SO2）及全身和空肠氧摄取率的变化；脱氧核糖核苷酸末端转移酶介导的原位缺口末端标记法（TUNEL）检测小肠细胞的凋亡。 结果 （1）感染性休克组全身氧摄取率(SO2ER)似有增加,但与对照组相比无显著性差异(P>0.05);（2）SS组小肠氧摄取率(IO2ER)逐渐增加,与基础值和C组相比有显著性差异（P<0.05）；（3）右心房血(混合静脉血)和肠系膜上静脉近端血PH随休克时间延长逐渐降低,BE负值逐渐增大,二者呈平行关系,与基础值和C组相比有显著性差异（P<0.05）；（4）感染性休克和对照组小肠粘膜细胞未发现有凋亡的发生。 结论 感染性休克时，全身氧摄取率不变，空肠局部氧摄取率增加，但组织缺氧始终存在，测定全身氧代谢不能代表局部氧代谢；休克发生2.5小时时小肠细胞未发现有凋亡的形态学变化，但有较多的白细胞聚集。更多还原

【Abstract】 Background Septic shock is the main cause of death which may induce multiple organ dysfunction syndrome(MODS).Because intestine is so-called the "primus motor" of MODS, it has special meanings to investigate its oxygen transport and pathological changes during septic shock, however, we have rarely seen such reports in chinese journals.Objective The purpose of present study was to observe alterations of systemic and jejunum oxygen extraction in rabbits with septic shock and whether focal cells apoptosis of intestine occurred . Methods Anesthetized New Zealand white rabbits [(2.20±0.15)kg] were randomly divided into septic shock group (SS group n=10, receiving a continously intravenous pumping of E.ColiO111B5) and control group (C group n=5 receiving normal saline ). The right jugular vein (right atrium)、left femoral artery、the approximal branch of superior mesenteric vein were cannulated ,.mean arterial pressure(MAP) and heart rate were monitored. .At 6 time points with half hour interval from 0 to 2.5 hours after pumping of E.ColiO111B5 and NS ,arterial and venous blood samples were simultaneously collected and blood gas analysis were done, then systemic O2 extraction ratio (SO2ER) and intestine O2ER(IO2ER) were calculated according to formula.In the present study, immunohistochemical staining(TUNEL) was used to detect apoptosis. Results In the SS group, SO2ER slightly increased which did not show significant difference compared to the C group(P>0.05). However, the PH values and base excess of the blood samples from right jugular vein decreased remarkablly with good correlation after 1.5 hours which showed significant difference compared to the control group (P<0.05). Whereas the IO2ER increased from 0.24 to 0.44 , it gradually increased at 0.5 hour time point then showed significant difference at 1 hour time point (P<0.05) and very significant difference at 1.5、2.0 and 2.5 time points(P<0.01)<WP=6>compared to control group. Meanwhile , the PH and base excess of the blood samples from superior mesenteric vein decreased in the same situation.Conventional light microscopy of hematoxylin and eosin(H&E) and immunohistochemical staining showed no apoptosis occurred in intestine. Conclusion During septic shock, the hemodynamics showed abnormal blood distribution while the cardiac output could be normal even higher which is different from other kinds of shock with lower cardiac output, therefore, the oxygen delivery and O2ER could keep normal even higher in septic shock while the tissues are poorly perfused. Although IO2ER -remains high in order to meet its high metabolic needs during septic shock which may be different from other abdominal organs, the higher O2ER may not be able to improve the local oxygenation which may be caused by mitochondrion dysfunction in cells.Focal apoptosis of intestine does not occur within 2.5 hours after septic shock.更多还原