血液动力学变化对血液流变学影响的研究进展

血液流变学是在流体力学基础上发展起来的一门关系到血液和循环两个系统生理功能的新兴边缘学科,是研究血液及其组成成分流变和变形规律的科学。近十几年来在我国发展十分迅猛,进行了许多研究,现综述如下:     

微循环与休克的血液动力学变化

本文的核心内容是应用生物物理学的理论探讨和分析了休克各阶段的血液动力学变化特点，并以公式和图解形式予以表述。我们分析认定休克的血液动力学变化是正反馈过程，这足医学史上首次以生物控制论的观点阐明休克的危重病因．可以预言生物控制论的理论和方法有可能对休克理论的发展产生影响。为便于理解上述内容，本文还介绍了相关的微循环生理学和生物物理学知识。     

海水浸泡失血性休克大鼠血液动力学的变化

目的探讨21℃海水浸泡失血性休克大鼠时血液动力学的变化规律及其同平原失血性休克大鼠血液动力学变化的比较.方法Wistar大鼠20只,随机分为平原失血性休克组和海水浸泡失血性休克组.右颈总动脉插管至左心室,运用四道生理记录仪监测血液动力学指标;失血性休克模型快速放血至50mmHg,维持低血压30min.平原失血性休克组在21℃室温下观察和测定血液动力学,海水浸泡失血性休克组浸入21℃模拟海水中(海盐浓度为2.535%),监测动物入水后10、30、60、180、300min时及平原失血性休克组相应时相点的血液动力学指标.结果海水浸泡失血性休克组动物心率显著下降,从伤前时(433±40)teats/min,降至入水5h时的(120±80)teats/min,而平原失血性休克组动物5h时的心率(288±14)teats/min,是海水浸泡失血性休克组的2.4倍,差别非常显著(P＜0.01);海水浸泡失血性休克组动物浸泡各时相点LVSP、±dp/dtmax均较伤前显著下降,并随着浸泡时间的延长而下降更加明显,浸泡5h时LVSP降为伤前的40%、平原失血性休克组同时相值的63%;浸泡5h时+dp/dtmax从伤前10.50±1.41降至3.20±1.24,-dp/dtmax从伤前7.53±1.42降为1.70±1.11,分别为平原失血性休克组5h时LVSP、±dp/dtmax值的56.5%、59.2%、59.4%.海水浸泡失血性休克组动物入海水早期血压明显升高,30min后很快下降,并随着时间的增加下降越明显,浸泡5h时血压值仅为平原失血性休克组同时相点的57%.结论21℃海水浸泡失血性休克动物血液动力学状态明显恶化,动物心肌电兴奋性、心肌收缩力、心肌顺应性均下降,伤情显著重于平原失血性休克动物,因此在治疗时要更加注意心功能状况和输液速度,防止心力衰竭.     

中风患者脑血管血液动力学参数变化及相关性分析

本文观察了中风患者脑血管血液动力学参数(CVHP)变化并分析了CVHP各指标的相关性联系及对脑血流量的影响。结果表明中风患者CVHP各指标均显著差于对照组(P<0.05～0.01);CVHP各指标均可见显著相关性联系;颈动脉最小血流量(Qmin、最小血流速度(Vmin)、平均血流速度(Vmean)、脑血管外周阻力(R)、脑血管零压顺应性(Co)、颈动脉最大血流量(Qmax)、和最大血流速度(V(max))及平均动脉血压(MBP)对脑血流量的多元回归方程起着主要作用。     

支架血液动力学

本文介绍了计算流体动力学（CFD）在模拟心血管系统血流的进展。特别在分流术支架血液动力学方面的应用。最后给出了两个支架血液动力学的模型,利用CFD技术计算了速度向量场和沿支架管壁的切剪应力分布,得出了在分流动脉内较理想流动的条件。     

血压与脑血管血液动力学指标（CVDI）的相关性研究

血压与脑血管血液动力学指标（ＣＶＤＩ）的相关性研究张立瑞，赵海英，张胜联（河北省复员军人医院）脑血管病是严重危害中老年人身体健康和生命的疾病之一，而高血压病是脑血管病首要的危险因素。动态地观察脑血管功能变化，判断高血压病与腋血管病的关系，对脑血管病的...     

妊高征不同血液动力学变化对母婴预后的影响

目的：探讨妊高征患者的血液动力学（CVT）变化及其对母婴预后的影响。方法：对226例妊高征患者按CVT结果分为正常组、低排高阻组、正常排高阻组，对其妊娠结局进行分析。结果：3组血液动力学监测改变与围产儿并发症及孕母预后的均有密切关系。提示：血液动力学监测对预测妊高征患者母子预后有重要的临床意义。     

肝硬化的血液动力学研究新进展

肝硬化是指各种原因作用于肝脏 ,引起肝脏弥漫性损害 ,使肝细胞变性坏死 ,残存的肝细胞形成再生结节 ,网状蛋白结构支架结构塌陷 ,结缔组织增生形成纤维隔 ,最终导致原有的肝小叶结构破坏 ,形成假小叶 ,在此基础上出现一系列肝功能损害与门脉高压症的临床表现。对我国人群流行病学调查研究发现 ,约 70 %肝硬化患者乙型肝炎病毒表面抗原阳性。近年来的研究表明 ,丙型和丁型肝炎病毒感染也与肝硬化有关。本文主要就病毒性肝炎肝硬化的血液动力学变化及其组织学基础作一综述。1　病毒性肝炎致肝硬化的病理学基础肝炎病毒长期或反复作用下 ,可致…     

脑梗死患者同型半胱氨酸水平及血液流变学指标的变化

脑梗死的发病率、致残率、死亡率都很高。其危险因素有高血压、高血糖、高血粘、高血脂、慢性炎症等。近年研究认为高同型半胱氨酸血症和高纤维蛋白原是脑血管疾病的相对独立危险因子。本文报道60例脑梗死患者血清同型半胱氨酸（Hcy）含量及血液流变学指标的变化。     

迷走神经在急性胆道高压所致血液动力学变化中的作用

急性梗阻性化脓性胆道炎（acuted妇tIUCUVsuppllr71［IVe山峦哈tis，AH）的重要病理生理特征是胆道压力的急剧升高，胆道高压能引起低血压或休克，其效应与交感神经有关，本文则重点观察迷走神经活动对血液动力学的效应和机制，探讨其与AOSC发病过程的关系。材料和方法（一）主要仪器与设备：u－42多道生理记录仪、OlivetteMx微机及MS－1215A型A／D接口。（二）实验动物模型：健康成年日本种长耳家兔，雌雄不拘，体重担．5【0．5）kg，术前禁饮食12h。用846合剂（0，2mwkg，tv），麻醉后复制以下模型：1．急性肛道高压模型：采用5cm…     

上海农村40岁以上人群脑血管血液动力学参数的分布特征

目的描述农村40岁以上人群的脑血管血液动力学参数的分布特征。方法以整群抽样方法抽取上海农村某社区40岁以上人群,进行脑卒中危险因素调查和血液动力学指标检测,按年龄、性别、左右颈动脉检测部位进行分组,分析和比较各组间血液动力学指标的差异及其整体分布特征。结果 40岁以上人群颈动脉最大(Vmax)、最小(Vmin)、平均(Vmean)血流速度,平均脑血流量(Qmean),舒张压与临界压的差值(Dp)等指标随着年龄的增长而呈现明显的降低趋势;脉搏波波速(Wv)、特性阻抗(Zcv)、外周阻力(Rv)、动态阻力(DR)和临界压(Cp)等指标随着年龄的增长而呈现明显的升高趋势。上述指标左右侧检测部位间和男女性别组间比较有一定差异,但无明显的变化规律。结论脑血管血液动力学检测指标变化与年龄增长密切相关。     

Drug treatments in the secondary prevention of ischaemic stroke

Stroke is an important cause of death and disability. However, about two thirds of cerebrovascular events are initially minor. They carry a high risk of potentially severe recurrent events, but they also offer an opportunity for secondary prevention to avoid such recurrences. As most recurrent events occur within a short time after the initial presentation, secondary prevention has to be started as soon as possible. Dramatic risk reduction can be achieved with well-established drugs if used in a timely manner. A standard secondary preventive regimen will address multiple vascular risk factors and will usually consist of an antiplatelet agent, a lipid lowering drug, and an antihypertensive agent. Depending on the risk factor profile of each patient, this will have to be adjusted individually, for example, taking into account the presence of cardioembolism or of stenotic disease of the brain-supplying arteries. In recent years, the approach to treating these risk factors has evolved. In addition to absolute blood pressure, blood pressure variability has emerged as an important contributing factor to stroke risk, which is affected differently by different antihypertensive agents. New oral anticoagulants reduce the risk of cerebral haemorrhage and the need for regular blood checks. The best antiplatelet regimen for stroke prevention is still uncertain, and treatment of dyslipidaemia may change if trials with cholesteryl ester transfer protein (CETP) inhibitors, which increase levels of HDL-cholesterol, are successful. This article reviews the current evidence for drug treatments in the secondary prevention of ischaemic stroke.     

中青年脑卒中患者脑血管血流动力学研究

目的探讨中青年脑卒中患者脑血管血流动力学特点。方法 48例中青年脑卒中患者和52例同期健康对照人群进行经颅多普勒脑血管血流动力学指标检测,并对两组进行比较分析。结果中青年脑卒中组双侧ACA、PCA及健侧MCA的Vm、PI和RI均较对照组显著增高,但MCA患侧的Vm较对照组及MCA健侧均明显降低,而其PI及RI中青年脑卒中组显著增高;P值均<0.01。结论中青年脑卒中患者存在明显的血流动力学改变,脑血管血流动力学检测对于中青年脑卒中患者早期诊断及治疗具有重要意义。     

脑卒中后血管性认知功能损害的临床观察

目的:对脑卒中后血管性认知功能损害的情况及治疗效果进行初步观察。方法:采用开放、自身前后对照研究方法,比较简易智能量表(MMSE)对49例脑卒中后患者进行治疗及血管性认知功能测试。结果:随访49例,有不同程度认知障碍者39例(79.6%),其中30例为轻度认知障碍(76.9%)。治疗前MMSE(25.41±3.10)分,治疗后4周及12周时MMSE分别为(26.84±6.18)分和(28.16±3.60)分,治疗前后MMSE分值差异有高度显著性(P<0.001)。结论:脑卒中后1~3个月轻度血管性认知功能损害普遍存在,治疗效果显著。     

Stop Stroke: development of an innovative intervention to improve risk factor management after stroke

OBJECTIVE: Stroke survivors are at high risk of stroke recurrence yet current strategies to reduce recurrence risk are sub-optimal. The UK Medical Research Council (MRC) have proposed a framework for developing and evaluating complex interventions, such as community management of stroke secondary prevention. The Framework outlines a five-phased approach from theory through to implementation of effective interventions. This paper reports Phases I-III of the development of a novel intervention to improve risk factor management after stroke. METHODS: The pre-clinical/theoretical phase entailed reviewing the literature and undertaking quantitative and qualitative studies to identify current practices and barriers to secondary prevention. In Phase I (modelling), findings were used to design an intervention with the potential to overcome barriers to effective stroke secondary prevention management. The feasibility of delivering the intervention and its acceptability were tested in the Phase II exploratory trial involving 25 stroke survivors and their general practitioners. RESULTS: This led to the development of the definitive risk factor management intervention. This comprises multiple components and involves using an on-going population stroke register to target patients, carers and health care professionals with tailored secondary prevention advice. Clinical, socio-demographic and service use data collected by the stroke register are transformed to provide an individualised secondary prevention package for patients, carers and health care professionals at three time points: within 10 weeks, 3 and 6 months post-stroke. CONCLUSION: The intervention is currently being evaluated in a randomised controlled trial. Further research is needed to test generalisability to other aspects of stroke management and for other chronic diseases. PRACTICE IMPLICATIONS: The MRC Framework for complex interventions provides a structured approach to guide the development of novel interventions in public health. Implications for practice in stroke secondary prevention will emerge when the results of our randomised controlled trial are published.     

Hypertension, cerebral vascular changes and stroke in Ghana. 1. Microaneurysm formation and stroke

A modification of the post-mortem arteriographic technique of Ross Russell was used to study the brains of 284 consecutive autopsy cases dying from non-traumatic causes; and made up of 159 hypertensives and 125 normotensives. Microaneurysms were demonstrated in 30.8 per cent of the hypertensives compared with 9.6 per cent normotensives. Haemorrhagic stroke was the cause of death in 37.6 per cent of the hypertensives, the majority of which were in younger age groups compared with hypertensive strokes in whites. The much lower incidence of microaneurysms in the brain of black hypertensives (even those with haemorrhagic strokes) compared with that found by workers among white hypertensives further emphasized the different nature of hypertension in blacks. It is suggested that, in the absence of significant structural differences in the cerebral vasculature between blacks and whites, the high incidence of haemorrhagic strokes occurring in the relatively younger subjects in Ghana may be due to the direct effect of high blood pressures on small intracerebral vessels and that microaneurysm formation may not be as important as in the much older white subjects dying of haemorrhagic strokes.     

主动脉转流对腹主动脉阻断所致血液动力学等改变的影响

目的:探讨不同流量主动脉转流对腹主动脉暂时性阻断时全身血液动力学等改变的影响。方法:实验建立在小猪腹腔动脉开口以上阻断腹主动脉1h和同时应用辅助主动脉转流的模型,监测血液动力学的变化,并观察组织学的改变。结果:阻断组发生了明显的血液动力学紊乱,尿量明显减少,代谢性酸中毒也极为明显,肝、肾和小肠组织及超微结构均发生了明显的病变。在主动脉转流组血液动力学的紊乱得到明显改善。结论:腹主动脉阻断1h将造成严重的全身血液动力学紊乱,当转流量达到原腹主动脉血流量的70%时主动脉转流能较好地防止这一损伤改变。     

全麻诱导时丙泊酚滴定给药与传统给药对患者血流动力学的影响

 目的：比较丙泊酚全麻诱导时滴定给药和传统给药对患者血流动力学的影响,以探求更安全、合理的麻醉诱导方案。方法：60例美国麻醉医师学会（American Society of Anesthesiology,ASA）分级Ⅰ~Ⅱ级、拟气管插管全麻下行择期手术的患者,随机分成2组,每组30例。Ⅰ组为传统给药组,按丙泊酚传统量2 mg·kg^-1以250 mg·min^-1的速度静脉泵注;Ⅱ组为滴定给药组,丙泊酚以1 mg·kg^-1·min^-1的速度静脉泵注,滴定至患者镇静警觉（OAA/S）评分1分,改为1  mg·kg^-1·h^-1维持。2组均在泵注丙泊酚的同时,给予芬太尼4 μg·kg^-1以注射泵注入。传统组给丙泊酚后1 min、滴定组入睡后给予顺阿曲库铵2  mg·kg^-1静推,4 min后行气管插管。记录诱导插管期间各个时点的收缩压（SBP）、舒张压（DBP）、平均血压（MBP）、心率（HR）和脉搏氧饱和度（SpO₂）。记录血压下降超过30%的例数。术后第2 d询问患者对插管过程是否有记忆。结果：2组均在一次试插即完成气管插管,术后随访均对插管过程无记忆。Ⅱ组SBP和MBP在给药后1 min、3 min及DBP在给药后1 min下降幅度均较Ⅰ组小（P<0.01）。Ⅱ组血压下降超过30％的例数较Ⅰ组少（P<0.01）。结论：和传统的给药方法相比,全麻诱导时丙泊酚滴定给药既能满足气管插管所需要的麻醉深度,又能避免血流动力学的剧烈波动。     

有机磷农药敌敌畏和对硫磷所致大鼠循环衰竭时的血流动力学特征

目的：在胆碱酯酶抑制剂（ChEI）类有机磷农药敌敌畏、对硫磷所致大鼠循环衰竭模型上，观察循环衰竭前后大鼠血流动力学及心电图变化，旨在阐明有机磷农药中毒引起的循环衰竭的血流动力学特征。方法:健康Wistar雄性大鼠，体重（320±20） g，腹腔注射累积染毒，直至平均动脉压（MBP）降至45 mmHg为循环衰竭标准。观察循环衰竭前后血流动力学指标及心电图变化。结果:2种农药所致大鼠循环衰竭时，收缩压（SBP）、舒张压（DBP）、平均血压（MBP）、心率（HR）、左室内压上升段最大变化速率（+dp/dt_max）、心肌纤维缩短速度（Vpm）以及+dp/dt_max与等容收缩期压力（IP）的比值（+dp/dt_max/IP）均显著低于染毒前，反映心脏舒张功能的左室舒张压（LVDP)、左室内压下降段最大变化速率（-dp/dt_max）、IP均显著高于染毒前（P<0.01）;心电图显示心率缓慢，心律失常。结论:有机磷农药导致大鼠循环衰竭时心率、心脏收缩功能和舒张功能均显著下降，心脏起搏与传导功能受损。     

The effects of cerebral white matter changes on cardiovascular responses to cognitive and physical activity in a stroke population

Autonomic nervous system (ANS) control may be disrupted by cerebrovascular disease. We investigated the relationship between alterations in white matter integrity and regulation of the ANS in 23 participants who sustained a stroke within 5 years. These participants underwent diffusion tensor imaging, and fractional anisotropy values were calculated (DTI‐FA) for each hemisphere and lobe. Cognitive and physical exertion tasks were performed while recording an electrocardiogram. Respiratory sinus arrhythmia (RSA) decreased more during a verbal fluency task with lower left hemisphere DTI‐FA. Further, the physical stressor yielded decreases in RSA with lower frontal DTI‐FA and higher temporal lobe DTI‐FA, p < .05 (perhaps a release effect on the central autonomic network). Decrements in ANS regulation may have functional consequences that alter behavior, as well as potentially increasing the risk for further vascular disease.