【作者】 叶文；

【导师】 王锦权； 高玉华；

【作者基本信息】 安徽医科大学 ， 麻醉学， 2007， 硕士

【摘要】 脓毒症(Sepsis)是由感染引起的全身性炎症反应综合征(systemic inflammatory response syndrome, SIRS),并证实有细菌存在或有高度可疑感染灶,是多器官功能障碍综合征(multiorgan dysfunction syndrome, MODS)的前兆。目前脓毒症和脓毒性休克仍然是世界重症医学所面临的难题,据统计,美国每年约有75万人发生脓毒性休克,病死率可达50%以上[1,2],深入探索脓毒症的病理生理和发生机制,寻找新的治疗脓毒症的方法,对指导临床治疗脓毒症,降低脓毒性休克的病死率具有重要价值。脓毒症时,内毒素等细菌成分作用于血管内皮,大量细胞因子释放,进一步引起促炎-抗炎系统失调和凝血功能紊乱,其中血管内皮细胞损伤在脓毒症凝血级联反应的发生发展过程中起着重要作用。本课题通过建立脓毒症模型,测定血浆血管性假性血友病因子(von Wilebrand factor, vWF)和内皮素(endothelin,ET)水平的变化,了解血管内皮损伤标志物的动态改变,并进一步研究脓毒症时肺组织vWF的表达,分析脓毒症时肺微循环内皮的损伤,为今后探明脓毒症的发病机制及寻求脓毒症治疗的新方法提供依据。目的:通过检测脓毒症兔血浆vWF和ET水平的改变,研究脓毒症对血管内皮的损伤作用;并采用免疫组化技术进一步研究脓毒症时肺组织vWF的表达,探讨脓毒症对肺血管内皮的影响,为指导脓毒症的治疗提供新思路。方法:新西兰白兔36只,随机分成3组:(1)正常对照组(n=12):通过兔耳缘静脉注射生理盐水;(2)脓毒症组(n=12):通过兔耳缘静脉注射大肠杆菌脂多糖(lipopolysaccharide, LPS)1mg·kg-1;(3)脓毒性休克组(n=12):通过兔耳缘静脉注射2mg·kg-1。各组动物均麻醉后分离出右侧颈总动脉及颈内静脉,经颈总动脉插管并连接压力换能器,监测平均动脉压、心率、呼吸频率。在静脉注射LPS后15min、30min、45min、60min、90min及120min时,经颈内静脉采血,然后分离血浆标本,进行vWF和ET的测定。vWF浓度采用酶联免疫吸附法(ELISA)测定, ET浓度采用非平衡放射免疫分析法测定。脓毒性休克组兔死亡后,立即开胸取肺标本,同期处死正常对照组及脓毒症组兔,取肺标本,应用免疫组化技术,检测肺组织vWF的表达。结果:1.脓毒症和脓毒性休克模型的建立实验动物静脉注射LPS 1mg/kg后,其血压无明显变化,而心率和呼吸频率逐渐升高,升高超过20%以上确立为脓毒症模型[3,4];实验动物静脉注射LPS 2mg/kg后,心率和呼吸频率升高超过20%以上,同时检测平均动脉压下降20%以上确立为脓毒性休克模型[3,4]。2.脓毒症时血浆vWF和ET水平均升高,脓毒性休克组升高更明显实验动物静脉注射LPS后,血浆vWF和ET水平均有不同程度的升高,但早期升高幅度并不明显,在脓毒症出现之后,血浆vWF和ET水平升高明显,随着病程的进展,尤其当实验动物出现脓毒性休克时,血浆vWF和ET显著升高,差异有统计学意义(P<0.05)。3.脓毒症兔肺组织vWF的表达增多,脓毒性休克组vWF表达增多更明显免疫组化检测结果显示,脓毒症组及脓毒性休克组兔肺组织vWF阳性染色面积分别占18.86±5.32%和35.58±5.45%,与对照组8.26±2.19%比较,均明显升高。结论:1.脓毒症早期就已出现血管内皮损伤,且损伤程度随着脓毒症的发展而加重。2.脓毒症对肺血管内皮的损伤是脓毒症对全身血管内皮损伤在肺脏中的表现,并随着脓毒症的发展,肺血管内皮损伤逐渐加重。3.血管内皮损伤逐渐加重引起组织微循环功能的障碍,可能在脓毒症及其引起的MODS中起着重要作用。以上研究结果为今后探明脓毒症的病理生理学以及寻求脓毒症和MODS治疗的新思路提供实验依据。中心静脉置管在临床上应用日趋广泛,各种中心静脉导管(Central venous catheter,CVC)用于血流动力学监测、给药、补液、胃肠外营养支持以及血液净化治疗等。随着穿刺工具、技术及导管材料的改进,长期应用的中心静脉通路变得安全、可靠,但插管后的感染时有发生。由置管引起的导管相关性脓毒症仍然是令临床医务人员感到棘手的严重并发症。在美国,每年院内血液感染约超过20万例,而这些感染中大多数与血管内装置的使用有关,其中90%与中心静脉导管有关,病死率为10%-20%;导管相关性血流感染在ICU院内感染中位居第三,病死率在ICU高达25%以上[1],中心静脉导管感染不仅增加医药费用,延长住院时间,而且对病人病情及生活质量产生不良影响。本课题通过对ICU中心静脉导管相关性血流感染(Central venous catheter-related bloodstream infection,CVC-RBI)病例进行研究,重点探讨CVC-RBI的菌群分布及药敏情况,明确引起CVC-RBI的相关易感因素,旨在为今后的临床应用提出建设性意见,更好地预防及处理CVC-RBI。目的:探讨ICU内中心静脉导管相关性血流感染的病原学、易感因素及临床特点,以指导临床更好地预防感染,减少CVC-RBI的发生,正确地处理CVC-RBI,更好地使用CVC服务于临床。方法:选取ICU中32例CVC-RBI确诊病例,患者皆为血流感染,分析其菌群分布及细菌耐药情况,并随机选择同期ICU收治的32例留置中心静脉导管但无相关性感染患者作为对照组,两组比较分析患者年龄、住院时间、血清白蛋白、格拉斯哥(Glasgow)评分、急性生理与慢性健康状况Ⅱ(APACHEⅡ)评分、肠内营养及气管切开等因素对CVC-RBI的影响。结果:32例CVC-RBI病例中,共分离出菌株35株,其中革兰阳性菌14株,革兰阴性菌10株,真菌11株;置管7天后CVC-RBI发生率逐渐增高(占90.63%);与对照组比较,CVC-RBI组患者年龄较大(P<0.05),住院时间、导管留置时间较长(P<0.05),入科时APACHEⅡ评分较高(P<0.01),血清白蛋白和格拉斯哥(Glasgow)评分较低(P<0.05和P<0.01),给予肠内营养者较少(P<0.05),气管切开数较多(P<0.05)。结论:对于住院时间较长、血清白蛋白低、病情危重度高、行肠外营养及高龄气管切开病人,尤其应注意CVC-RBI的发生;重视抗生素的合理应用,应根据已存在的危险因素采取相应措施。以上研究结果为今后指导临床使用CVC及寻求预防和治疗CVC-RBI新方法提供了重要依据。更多还原

【Abstract】 Sepsis is the systemic inflammatory response to infection and premonition of multiple organ dysfunction syndrome. Nowadays, sepsis and septic shock are still the puzzle of critical care medicine in the world. Among about 750,000 patients with septic shock every year in the United States, the case fatality exceeds for 50 percent. To explore pathologic mechanism of sepsis and seek for approach to treating sepsis will have important value to instruct sepsis treating and decrease the mortality of septic shock. After blood vessel endothelium is injured by lipopolysaccharide(LPS) in sepsis, a great quantity cytokine released from endothelial cell causes the unbalance of inflammatory and anti-inflammatory system and coagulation functional disorder. In the study, sepsis model was established, and the change of blood plasma von Wilebrand factor(vWF) and endothelin(ET) were determined, and expression of vWF on lung was observed. Blood vessel endothelium injury was studied for investigating the mechanism of sepsis and seeking new approach of therapy.Objective To explore blood vessel endothelium injury in sepsis by determining the change of plasma vWF and ET, and investigate pneumonic blood vessel endothelium injury in sepsis by observing expression of vWF on lung tissue.Methods 36 New Zealand white rabbit were randomly divided into three groups(control group, sepsis group and septic shock group). 0.9% sodium chloride, LPS(1mg/kg) and LPS (2mg/kg) were injected into three groups through ear fringe vein respectively. After pressure transducer was connected with common carotid artery cannula,mean arterial pressure(MAP),heart rate(HR) and breathing frequency were monitored. In the time of 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes and 120 minutes after injecting LPS, plasma vWF and ET were respectively determined by enzyme-linked immunosorbent assay and radio immunoassay. After the rabbit in the septic shock group died, lung preparation were taken and expressions of vWF on lung tissue were detected by immunohistochemical method.Results1 Sepsis and septic shock model were established.After LPS(1mg/kg) was injected into experimental animal through ear fringe vein, MAP had no obvious change, HR and breathing frequency guadually increased over 20 pencent, sepsis model was established. After LPS(2mg/kg) was injected into experimental animal, HR and breathing frequency guadually increased over 20 pencent, and MAP decreased over 20 pencent, septic shock model was established.2 Blood plasma vWF and ET increased in sepsis group and higher in septic shock groupBlood plasma vWF and ET increased remarkably after LPS was injected. Compared with control group, the extent of increasing was not clearly in the early time after injecting LPS. But when experimental animal developed septic shock, Blood plasma vWF and ET increased obviously(P<0.05).3 Expressions of vWF on lung tissue increased in sepsis and more obviously in septic shockImmunohistochemistry result displayed that positive staining of vWF was 18.86±5.32% in sepsis group and 35.58±5.45%in septic shock group, which increased obviously compared with 8.26±2.19% in control group. Conclusions1 Blood vessel endothelium injury happens in the early time of sepsis, and degree of injury aggravated along with the development of sepsis.2 Pneumonic blood vessel endothelium injury is not only the pneumonic manifestation of systemic blood vessel endothelium injury but also aggravates along with the development of sepsis.3 Blood vessel endothelium injury and dysfunction of microcirculation may play an important role in sepsis and multiorgan dysfunction syndrome(MODS).All above mentioned research results may provide the experimental basis for exploring the pathophysiology of sepsis and finding the new methods about treating sepsis and MODS. Central venous catheter is used in hemodynamic monitoring, administering fluid infusion, parenteral nutrition and blood purification. In spite of the improvement of puncturation and catheter materials, central venous catheter-related bloodstream infection(CVC-RBI) is still the severe formidable complication. In the United States of America, the number of nosocomial infection exceeds for 200,000 every year, 90 percent of which is related to central venous catheter. Catheter-related bloodstream infection, whose case fatality reaches up to 25 percent in ICU, ranks the third of nosocomial infection in ICU. CVC-RBI not only raises medical expenses, lengthens the time of hospitalization, but also is harmful to patient’s state and quality of life. In the present study, the cases of CVC-RBI in ICU are investigated. Etiology and predisposing factor of CVC-RBI are explored so as to prevent and handle CVC-RBI.Objective To discuss the etiology, predisposing factor and clinic characteristic of CVC-RBI in ICU, for preventing infection and decreasing CVC-RBI, handle CVC-RBI, using CVC better in clinical work exactly.Methods The common pathogens and the risk factors of CVC-RBI were analyzed in 32 cases of CVC-RBI chosen from ICU, which was compared with the control group on patient’s age, the time of hospitalization, serum albumin, Glasgow coma scales, APACHEⅡscore, enteral nutrition and incision of trachea.Results Among 32 cases with CVC-RBI, 35 pathogens were isolated,including 14 gram-positive bacterium, 10 gram-negative bacterium and 11 fungi. The incidence of CVC-RBI increased gradually after the seventh day of the insertion of catheter(90.63%). Compared with the control, 32 cases with CVC-RBI were older(P<0.05), had more length of stay in hospital and insertion time of catheter(P<0.05), higher APACHEⅡscore(P<0.001), lower serum albumin level(P<0.05) and Glasgow coma scales (P<0.001), less enteral nutrition(P<0.05) and more incision of trachea(P<0.05).Conclusions CVC-RBI should be paid attention to in older critical patients with hypoalbuminemia, incision of trachea or parenteral nutrition. Antibiotic should be used reasonably and adopt a corresponding measure according to risk factors.All above-mentioned research results may provide the important basis for using CVC in clinic work and finding the new methods about preventing and treating CVC-RBI.更多还原