低血容量状态下患者每搏量变异度与血容量的相关性

目的 探讨低血容量状态下患者每搏量变异度(SVV)与血容量的相关性.方法 择期骨科手术患者20例,年龄20 ～ 64岁,BMI 20 ～ 30 kg/m2,ASA分级Ⅰ或Ⅱ级.气管插管后,稳定5 min,记录HR、MAP、CVP、动脉压力波形监测的心排量(APCO)、SVV、全身血管阻力(SVR)和心脏指数(CI).以30 ～ 50 ml/min的速率从中心静脉取血,取血量为全身血容量的5％,待血液动力学稳定5 min后记录上述血液动力学指标;再次以上述方法采血并记录血液动力学指标;随后以50 ～ 70 ml/min的速率经右侧颈内静脉输注相当于全身血容量5％的6％羟乙基淀粉130/0.4,待血液动力学稳定5 min后记录血液动力学指标;再次以上述方法补液并记录血液动力学指标.血容量变化(各时点血容量与基础值的差值)与dSVV(各时点监测值与基础值的差值)行线性相关分析.结果 每次血容量变化后SVV、APCO和CI与前一状态比较差异均有统计学意义(P＜0.05或0.01),每次血容量变化后HR、MAP、CVP和SVR与前一状态比较差异并非均有统计学意义;dSVV与血容量变化呈负相关(r=-0.875,P＜0.01).结论 低容量状态下SVV与血容量的相关性较高,可准确反映血容量的变化,可用于指导低血量容状态下的容量治疗.     

尿激酶原基因疗法防治血管吻合口血栓形成

为了探讨尿激酶基因疗法对血管吻合口血栓形成的预防作用，用浸泡过ｐＮ２－ｐｒｏ－ＵＫ质粒溶液的医用缝线，进行大鼠总动脉产端端吻合。提取吻合口组织ＲＮＡ与ｐｒｏ－ＵＫ５探针进行Ｎｏｒｅｈｅｒｎ印迹杂交，应用纤维蛋白平板溶圈法检测吻合口组织的纤溶酶活力并进行粘附于吻合口同位素标记的血小板计数和吻合口病理观察。     

吻合方法、抗凝治疗对犬下腔静脉吻合口血栓形成的影响

目的 观察吻合方法、抗凝治疗对犬下腔静脉吻合口血栓形成的影响,探讨血管吻合术后血栓形成的相关危险因素.方法 成年健康杂种犬30条,随机分6组,即空白对照组、假手术组、连续吻合抗凝组、连续吻合不抗凝组、间断吻合抗凝组、间断吻合不抗凝组.采用不同的吻合方法制造犬下腔静脉吻合模型,术后抗凝组给予抗凝治疗,其余各组等量生理盐水对照.术前、术后第1天、术后第3天测定各组实验犬血清血栓前体蛋白(TpP)的含量,术后1周各实验犬行彩色多普勒超声检查及经股静脉行下腔静脉造影观察下腔静脉通畅情况,造影后切取吻合处及两端少许正常血管,进行形态学观察.结果 血管造影、彩超、TpP的含量测定及形态学检查结果均显示,连续吻合不抗凝组和间断吻合不抗凝组血栓形成指标与其他组之间差异有统计学意义(P＜0.05),两组血栓阳性率分别为80%(4/5)、100%(5/5).结论 静脉血管吻合术后缺乏有效的抗凝治疗,是术后血栓形成的危险因素,及时有效的抗凝治疗有助于减少术后血栓的形成.不同的血管吻合方法不是血管吻合术后血栓形成的危险因素.     

6％羟乙基淀粉130/0.4容量治疗对低血容量兔肠系膜微循环的影响

目的 评价6％羟乙基淀粉130/0.4容量治疗对低血容量兔肠系膜微循环的影响.方法 雄性成年家兔64只,体重2.0～ 2.3 kg,采用随机数字表法,将其随机分为4组(n＝16):对照组(C组)、低血容量组(HM组)、乳酸钠林格氏液组(RS组)和6％羟乙基淀粉130/0.4组(HES组).家兔麻醉后行右颈内静脉、股动脉和股静脉穿刺置管.C组不放血;M组经30 min股静脉放出30％血容量的血;S组和H组放血结束即刻经30 min右颈内静脉分别输注3倍放血量的乳酸钠林格氏液和等放血量的6％羟乙基淀粉130/0.4.于放血前(T0)、放血结束即刻(T1)、补液结束即刻(T2)和补液结束后30min(T3)时,记录MAP和HR,同时采集股动脉和股静脉血样,进行血气分析,计算氧供(DO2)、氧耗(VO2)和氧摄取率(ERO2);测定微动脉和微静脉的直径和血流速度.结果 与C组比较,HM组T1～3时HR加快,MAP降低,微血管直径缩小,血流速度减慢,T1时DO2升高(P＜0.05).与HM组比较,RS组T2时MAP升高,T2.3时HR减慢,T1～3时DO2和VO2升高,微动脉直径T2时增大,T3时缩小,T2.3时微静脉直径增大,微血管血流速度加快,HES组T2时MAP升高,T2.3时HR减慢,VO2和ERO2升高,微动脉和微静脉直径增大,血流速度加快(P＜0.05).与RS组比较,HES组T3时DO2、VO2和ERO2降低(P＜0.05).结论 6％羟乙基淀粉130/0.4容量治疗可改善低血容量兔肠系膜微循环,增加组织灌注,改善氧代谢.     

咪唑安定对低血容量休克鼠静脉血管可容性的影响

目的研究咪唑安定对低血容量休克血管可容性的影响及可能的作用机制。方法血管可容性的变化通过测量注射咪唑安定前后全身平均循环充盈压(Pmcf)来表示。实验鼠分为对照组(n=8),交感神经阻断组(SNSB,n=8),交感神经阻断 去甲肾上腺素组(SNSB NA,n=9),低血容量组(n=5)。静脉注射咪唑安定0.1、0.3、0.5、1.0mg·kg-1后2min测量Pmcf。结果与用药前相比,咪唑安定导致对照组、低血容量组、SNSB NA组平均动脉压明显下降(P<0.05),但对照组呈剂量依存性方式。对照组和低血容量组的Pmcf呈现剂量依存性下降(P<0.05),但SNSB组、SNSB NA组无改变。结论 咪唑安定可引起剂量依存性的静脉血管舒张,而这种作用主要是源于其对静脉血管交感神经张力的抑制。     

尿激酶原基因疗法防治小血管吻合口血栓形成和内膜增生的实验研究

目的：探讨尿激酶原（Pro-uk)基因疗法对小血管吻合口血栓形成和内膜增生的影响。方法：切断大鼠颈总动脉,进行原位端端吻合,向听合口血管腔内注入复制缺陷的腺病毒载体Adv5-CMV溶栓（对照组）或复制缺陷的腺病毒重组体Adv5-CMV-Pro-uk溶液（治疗组）,使之在腔内滞留30min。应用纤维蛋白平板溶圈法检测吻合口组织的纤溶酶活性以观察Pro-uk基因的表达,并进行粘附于吻合口同位素标记的血小板计数、吻合口组织的掺入量和病理形态学检测。结果：治疗组术后2、7、14和90d均检测到纤溶酶活力,术后第7d活力最高,对照组未检测到纤溶酶活力。治疗组粘附于吻合口同位素标记的血小板数目、^3H-TdR掺入量、吻合口血栓出现率和内膜面积均明显少于对照组。结论：将腺病毒载体介质的Pro-uk基因转入吻合口血管壁中可减少吻合口血小板沉积和粘附,有效地防止血栓形成和内膜增生。     

哌库溴铵对低血容量犬血流动力学的影响

成年杂种犬２４只，随机分为二组：低血容量模型组 ８只，低血容量实验组 １６只，采用 ＧｏｕｌｄＩｍ１０００电脑监测仪创伤性监测血流动力学指标，选用Ｄｅｓａｌ休克模型法制造低血容量模型，放血后，放血量几乎为犬总血量的５０％，两组犬血流动力学指标明显改变，心电图出现Ｔ波倒置，ＳＴ段水平下移缺血性改变。有此基础上，低血容量实验组给４０ｕｇ／ｋｇ的哌库溴铵，而低血容量模型组不给药，１小时内两组犬血流动力学指标无明显改变，心电图缺血性改变来见加重，两组犬各时间点血流动力学指标无明显差异。因此，哌库溴铵对低血容量犬血流动力学无明显影响，可考虑用于临床休克患者。     

尼卡地平与硝酸甘油对血容量影响的比较

尼卡地平是第二代二氢吡啶类钙通道阻滞药。它选择性作用于心脑血管 ,扩血管作用效能强 ,而对心肌收缩力及心脏的电生理影响很小[1] 。本组通过观察在体外循环流量稳定条件下 ,尼卡地平对氧合器中储血器血平面及平均动脉压的影响 ,了解该药对血容量的影响 ,并与硝酸甘油作比较。资料与方法一般资料　体外循环下行心血管手术者 15例 ,年龄 15～ 69岁 ,男 5例 ,女 10例 ,ＡＳＡⅡ～Ⅲ级 ,临床心功能Ⅱ～Ⅲ级 (ＮＹＨＡ)。其中 ,风湿性心脏病行瓣膜置换术者 10例 ,先天性心脏病行房缺、室缺修补术者 4例 ,冠状动脉粥样硬化性心脏病行冠状动脉搭…     

羟乙基淀粉对低血容量性休克兔毛细血管渗漏的影响

目的通过正交实验设计,观察6%羟乙基淀粉(6%HES)、复方氯化钠实验研究和生理盐水在低血容量性休克不同阶段的治疗作用及对毛细血管渗漏的影响。方法确立实验因素为液体种类、给液剂量和给液时机,实验水平数为三水平,由此选用L9(34)正交表。随机选择27只健康新西兰大白兔,根据正交表顺序建立失血性休克模型,在不同时机输入相应的液体。输液后,由颈内静脉注入伊文思蓝(EB),观察3h后处死,(1)取右肺中叶0.5g组织,计算含水率;(2)用EB标准品测出EB标准曲线,计算出伊文思蓝含量回归方程;(3)取右肺中叶0.1~0.3g组织,碾碎后用甲酰胺萃取EB,离心后用分光光度仪测EB吸光度,根据EB回归方程计算出EB含量;(4)观察肺病理变化。结果肺含水率和EB含量方差分析结果均表明A(液体种类)、B(给液剂量)和C(给液时机)三个因素均有统计学意义,A为主要因素,其次为B,再次为C。病理结果A1B3C2组肺损伤最轻,其他由轻到重依次为A1B2C2、A3B3C2、A1B3C3、A3B2C1、、A2B2C3、含B1的三组,A2B3C1肺损伤最重。结论选择中分子羟乙基淀粉(200/0.5)20ml/kg于休克代偿期输入,可降低肺毛细血管通透性,减轻肺水肿及肺损伤,对低血容量性休克时肺毛细血管渗漏可能有治疗作用。     

早期乳酸清除率评估与失血性低血容量休克预后的研究

目的评估失血性低血容量休克患者早期乳酸清除率与预后的关系。方法前瞻性观察并收集因失血性低血容量休克进入外科重症监护病房92例患者的APACHEII评分、入ICU6h后动脉血乳酸清除率及患者预后。分别将患者分成存活组和死亡组,高乳酸清除率组(6h乳酸清除率10%)和低乳酸清除率组(6h乳酸清除率10%),比较各组间的差异。结果各组年龄、性别、APACHEII评分和基础血乳酸值差异无统计学意义。存活组乳酸清除率明显高于死亡组[(29.8±15.2)%vs(9.8±9.1)%,0.01];高乳酸清除率组病死率均明显低于低乳酸清除率组(11.3%vsP42.9%,P0.01)。结论早期乳酸清除率10%能准确评估失血性低血容量休克患者的良性预后。     

Argon laser coagulation of blood for the anastomosis of small vessels

A new technique is introduced in which an argon laser coagulates blood to form an adherent sleeve for the anastomosis of small vessels. The argon laser solidifies the blood into a dark tensile substance which supports the site of repair until vascular continuity is achieved. Laser pulses of 0.75 W and 0.5 seconds exposure are used, and damage to the underlying vessel wall is minimal. A histological analysis is performed and the results are examined qualitatively. The technique shows advantages of speed, reduced vascular trauma, and external protection at the site of vascular repair.     

Disorders of blood coagulation during and after arterial vascular reconstruction

In spite of a systemically increased clotting tendency in progredient arteriosclerosis there are locally restricted haemorrhagic sequelae following arterial vasoreconstruction. Because of the fact that each bleeding simultaneously includes the risk of wound infection with subsequent sepsis the formation of a haematoma is to be avoided in the surgical procedure. The development of disseminated intravascular coagulation caused by sepsis and that caused by massive haemorrhage are represented as to their clinical importance. Finally, an internationally accepted substitution concept for severe bleeding sequelae, e.g. in case of the rupture of an aortic aneurysm, is submitted.     

Hypercoagulable states and antithrombotic strategies in recurrent vascular access site thrombosis

Vascular access site thrombosis is a major cause of morbidity in patients receiving hemodialysis. The role of hypercoagulable states in recurrent vascular access site thrombosis remains poorly understood. Data are limited regarding systemic anticoagulation to improve access graft patency, because of concern about hemorrhagic complications. We determined the prevalence of hypercoagulable states and clinical outcome (thrombotic and hemorrhagic) after initiation of antithrombotic therapy in a series of patients with recurrent vascular access site thrombosis. We evaluated 31 patients who had sustained 119 thrombotic events that resulted in vascular access graft failure during the year before evaluation. Sixty-eight percent of patients tested had elevated concentrations of antibody to anticardiolipin or topical bovine thrombin, and 18% of patients tested had heparin-induced antibodies. More than 90% of patients had elevated factor VIII concentration, 62% had elevated fibrinogen concentrations, and 42% had elevated C-reactive protein concentrations. Twenty-nine patients were given antithrombotic therapy: 13 with warfarin sodium, 12 with unfractionated heparin (UFH), and 11 with low molecular weight heparin (LMWH). Seven patients received more than one antithrombotic agent, sequentially. Nineteen patients have had no thrombotic events since beginning antithrombotic therapy (10 with warfarin, 3 with UFH, 6 with LMWH). Mean follow-up was 8.6 months (median, 7 months). Eight patients sustained 10 bleeding complications (5 with warfarin, 3 with UFH, and 2 with LMWH). In conclusion, hypercoagulable states are common in patients with recurrent vascular access site thrombosis. Antithrombotic therapy may increase vascular access graft patency, but is associated with significant risk for hemorrhage. Prospective studies are needed to evaluate the role and safety of antithrombotic agents in improving vascular access graft patency.     

Effect of bipolar coagulation and occlusion clamping on the patency rate in microvascular anastomosis

Even with extremely high output from a bipolar coagulator applied close to a vessel, the patency in the femoral arteries and veins of 20 rats was found to be excellent. Scanning electron microscopy and histopathologic studies showed minimal disturbances within the intima. When the extremely high pressure (350 gramforce/mm2) of the Ikuta microvascular occlusion clamp was applied to the rat femoral veins for 1 hour, only one out of six veins became nonpatent. Lower pressures had no detrimental effects on the other 33 veins. When high clamping pressure and high output bipolar coagulation were applied together in 20 femoral veins of the rat, patency rate was 80 percent. From the results, it appears that bipolar coagulation is extremely safe, while clamping can be harmful to patency in microvascular anastomoses.