高渗盐液经骨髓腔通路复苏失血性休克犬的实验研究

目的 探讨经骨髓腔通路输注高渗盐液对失血性休克犬的复苏效果及其体内微环境的改变.方法 健康雄性家犬18只,体重16～19kg,应用随机数字法分为3组:HSH组、NS组和Sham组,每组6只.建立犬失血性休克模型.HSH组经骨髓腔快速推注7.5%高渗氯化钠羟乙基淀粉复苏液体(HSH:1 000ml 6%羟乙基淀粉40溶液中加入66g Nacl),NS组推注0.9%生理盐水;Sham组动物仅行全身麻醉、呼吸机辅助呼吸,不做放血和输液处理.观察复苏后犬血流动力学、髓内压、血钠及乳酸水平的改变.结果 休克后,HSH组和NS组平均动脉压(MAP)、中心静脉压(CVP)和髓内压与相应时间点Sham组相比均显著下降(P＜0.05),乳酸水平显著上升(P＜0.05).经骨髓腔通路复苏后,HSH组MAP、CVP和髓内压与相应时点NS组相比均显著升高(P＜00.05),与相应时点Sham组相比无显著性差异(P＞0.05).乳酸水平较休克期显著下降(P＜0.05).复苏后血钠水平暂时上升,并在复苏后120min降至基础水平.复苏后NS组MAP、CVP和髓内压显著低于相应时点Sham组水平(P＜0.05),复苏后120min血乳酸水平显著高于基础值(P＜0.05).结论 采用小剂量HSH复苏能够改善血流动力学指标和稳定内环境,是一种安全、有效的复苏方案.     

复方高渗盐溶液对大鼠低血容量性休克心肌细胞膜泵功能的影响

目的 探讨低血容量性休克大鼠心肌细胞膜泵功能的变化及高渗盐溶液对其泵功能的影响。方法 成年Wistar大鼠96只，随机分成高渗盐溶液组（HSH组）和生理盐水组（NS组），每组48只。双阶段放血法制备大鼠休克模型，按休克不同时相分为休克前、休克及复苏后30、60、90、120min6个时相，分别测定心肌细胞膜ATP酶活性并行心肌细胞超微结构观察。结果 HSH组中休克时的心肌细胞膜ATP酶活性明显低于休克前及复苏后90、120min（P〈0．05），而NS组休克时和复苏后各时间点心肌细胞膜ATP酶活性均明显低于休克前（P〈0．05）。HSH组复苏后各时间点心肌细胞膜ATP酶活性均明显高于NS组（P〈0．01）。结论 低血容量性休克可导致心肌细胞膜ATP酶活性降低，能量消耗增加，细胞膜离子泵功能衰竭；复方高渗盐液不但能快速改善休克引起的血容量不足，而且能恢复心肌细胞膜离子泵功能。     

低血容量性休克大鼠心肌细胞Ca2+浓度及膜电位的变化

目的 旨在探讨低血容量性休克大鼠心肌细胞Ca2 浓度及其膜电位的变化.方法 选用Wistar大鼠84只,随机分成休克高渗复苏组(HES组)、生理盐水复苏组(NS组).建立休克模型,按7个时相(休克前、休克、复苏后5、15、30、60、90min)处死大鼠.取心室肌细胞培养传代,用Fluo-4/AM为游离钙荧光探针、JC-1荧光染色,流式细胞仪分别检测不同时相心肌细胞Ca2 浓度及线粒体膜电位.结果 HES组在休克、复苏后5、15、30min各时间点心肌细胞Ca2 浓度较休克前明显升高,其膜电位较休克前显著降低(P＜0.01);在复苏后60、90min心肌细胞Ca2 浓度及线粒体膜电位与休克时比较差异有显著性意义(P＜0.01);NS组在休克、复苏后各个时相与休克前比较心肌细胞Ca2 浓度均明显升高,其膜电位明显下降(P＜0.01);复苏后各时间点与休克时比较差异无显著性意义(P＞0.05);HSE组和NS组在休克后60、90min心肌细胞Ca2 浓度及其膜电位差异有显著性意义(P＜0.01).结论 低血容量性休克可诱发大鼠心肌细胞Ca2 浓度升高,线粒体膜电位下降,导致心肌细胞电生理活动障碍;高渗盐溶液不但可改善低血容量休克时心肌细胞Ca2 浓度,而且能有效地稳定其线粒体膜电位;而生理盐水对心肌细胞Ca2 浓度及其膜电位的作用不显著.     

控制性与非控制性失血性休克早期液体复苏的对比研究

目的 比较在失血已控制及失血未控制两种状态下常规液体复苏治疗失血性休克的效果,探索早期液体复苏对策.方法 健康雄性SD大鼠28只,随机分为对照组(n=8)、失血已控制休克组(CHS组,n=10)及失血未控制休克组(UHS组,n=10).CHS组及UHS组大鼠股动脉放血,使血压在15min内降至30mmHg,然后截断3组大鼠尾根部,对照组及CHS组立即结扎止血,UHS组不予处理使其自然流血.模拟战创伤实际情况,将动物分为院前期(30 ～ 90min)、医院救治期(90～ 150min)及康复期(150min～72h)3个阶段.院前期通过输液将大鼠血压维持在60mmHg;医院救治期结扎出血灶,输血、输液维持大鼠血压至90mmHg;康复期观察至72h.监测平均动脉压(MAP)、中心静脉压(CVP)、心功能、血气分析及血细胞比容(Hct)、血乳酸水平等,观察记录出血量、补液量及动物存活时间.结果 根据实验设计,通过液体复苏使CHS组及UHS组大鼠院前期及医院救治期MAP分别维持在60mmHg及90mmHg.CHS组及UHS组同一时相MAP及CVP均无显著差异.院前期UHS组大鼠Hct明显低于CHS组.自院前期开始,UHS组大鼠血乳酸水平即持续性升高,而医院救治期以后CHS组血乳酸水平升高不明显.从医院救治期开始UHS组心率及最大心室内压上升速度明显低于CHS组.液体复苏后CHS组动物酸中毒及低氧血症得到明显纠正,但UHS组仍持续处于低氧血症及酸中毒状态.CHS组院前期补液量(44.5±10.1ml/kg)明显低于UHS组(74.5±11.4ml/kg,P＜0.01).CHS组及UHS组72h死亡率分别为30％及80％.结论 较失血已控制的休克而言,对失血未控制的休克进行快速复苏可导致出血量增加、血液稀释、心功能损害及死亡率增加.     

HSD与多巴胺伍用对初进高原大鼠失血性休克合并肺水肿的治疗作用

目的　探讨高渗氯化钠右旋醣酐 (7.5 %NaCl 6 ?xtran4 0 ,HSD)与多巴胺 (DA)合用对初进高原大鼠失血性休克合并肺水肿的的治疗效果。方法　初进高原SD大鼠 4 2只 ,复制失血性休克合并肺水肿模型。实验分为非处理组、失血性休克合并肺水肿对照组、乳酸林格氏液对照组 (4ml kg ,LR)、HSD单用组(4ml kg)、多巴胺单用组 (2mg kg ,DA)和HSD与DA合用组 ,每组 7只动物。观察给药后 15、30、6 0和 12 0分钟时相点大鼠血流动力学指标变化、30分钟和 12 0分钟大鼠血气指标变化以及 12 0分钟大鼠肺脑含水量变化。结果　HSD或DA单用可显著升高休克合并肺水肿大鼠血压 (MAP)、左心室内压 (LVSP)和左室内压最大变化速率 (±dp dtmax)等血流动力学指标 (P <0 .0 5～ 0 .0 1) ,改善部分血气指标如pH值、[HCO3- ]、血氧饱和度 (O2 sat)和降低肺、脑含水量。二者合用效果优于两者单用。结论　HSD与DA伍用有较好的改善高原失血性休克合并肺水肿的血流动力学指标 ,改善血气指标和减轻肺水肿的作用 ,可作为治疗高原休克合并肺水肿的早期救治措施之一。     

重症失血性休克大鼠血小板线粒体变化及虎杖苷的干预作用

目的 探讨重症失血性休克大鼠血小板线粒体变化程度与休克轻重程度的关系.方法 选择36只Wistar大鼠并按随机数字表法分为假手术组、休克30,60,120 min组、休克120 min+等渗盐水+输血组(NS组)及休克120 min+虎杖苷+输血组(PD组),每组6只.荧光素-荧光素酶试剂盒测定血小板三磷酸腺苷(adenosine triphosphate,ATP)含量;电镜观察血小板线粒体形态;Calcein-AM和CoCl2测定线粒体通透性转变孔状态;JC-1线粒体膜电位试剂盒探测线粒体膜电位(△Ψm)变化;过氧化脂质(lipid hydroperoxide,LPO)试剂盒检测血小板中LPO;吖啶橙(acridine orange,AO)检测血小板溶酶体稳定性. 结果 休克60 min组血小板ATP合成显著减少(P＜0.01),ATP含量随休克时间增加而减少,在NS组中减少最为明显[为正常值的(50.75±9.15)％].休克30 min组出现线粒体肿胀,嵴结构模糊消失,线粒体膜电位(△Ψm)下降及溶酶体稳定性下降(苍白细胞增多);休克60 min组钙黄绿素荧光减弱(P＜0.01).PD组上述各指标都有所改善,特别是血小板ATP水平恢复到正常值的(79.57±8.48)％. 结论 重症休克30～60 min时发生血小板线粒体功能不全,血小板线粒体功能检测可作为重症休克诊断和治疗的一项非损伤性指标.     

小容量复苏对失血性休克犬血流动力学及内脏组织灌注的影响

目的 探讨小容量复苏对失血性休克犬早期血流动力学及内脏组织灌注的影响.方法分别给予6 ml/kg高渗盐水(HS组)和6 ml/kg高渗盐水加羟乙基淀粉溶液(HSS组)对失血性休克犬进行容量复苏,并以失血量3倍的等渗盐水(NS组)作对照,观察复苏后早期血流动力学及胃肠黏膜组织灌注指标小肠黏膜pH值(pHi)的变化. 结果 (1)3种溶液均能改善失血性休克犬复苏的早期血流动力学及组织灌注,但在30 min后高渗盐水、HSS及等渗盐水容量指标下降,血流动力学下降,其中高渗盐水及等渗盐水下降最为明显.(2)随着血流动力学下降,3组pHi于120 min后开始下降,而动脉乳酸无升高. 结论 (1)小容量高渗盐水在失血性休克模型中的复苏效果与等渗盐水类似,小容量高渗盐水加羟乙基淀粉溶液的效果优于前两组.(2)pHi是监测组织灌注的良好指标,比动脉乳酸更为敏感.     

高渗高胶液对肺创伤合并失血性休克兔的脑保护作用

目的 探讨高渗高胶液(4.5g/ml氯化钠联合6.0 g/ml羟乙基淀粉,简称HHS)对肺创伤合并失血性休克兔脑保护作用及其可能机制. 方法 30只新西兰大耳白兔按随机数字表法分为三组:A组为对照组,B组为乳酸林格液(LRS)组,C组为HHS组;每组10只.B、C组建立肺创伤合并失血性休克模型,休克维持60 min后,以3倍失血量的LRS和5ml/kg的HHS分别对两组兔进行液体复苏.复苏后4h处死各组动物并取脑组织,荧光显微镜下观察各组脑组织顶叶皮层伊文蓝渗出情况,称量并计算脑含量水,TUNEL法检测凋亡神经元,Western blot检测Bcl-2和Bax蛋白表达. 结果 与A组比较,B组顶叶皮层有大量伊文蓝渗出,脑含水量显著增加,并出现大量凋亡神经元,Bcl-2和Bax蛋白表达增加,但Bcl-2/Bax比例降低(P＜0.01);与B组比较,C组顶叶皮层伊文蓝渗出明显减少,脑含水量显著降低,凋亡神经元数量减少,Bcl-2/Bax比例显著增高(P＜0.05). 结论 HHS通过改善血脑屏障功能、抑制神经元凋亡对肺创伤合并失血性休克兔脑起到一定的保护作用.     

精氨酸血管加压素对海水浸泡合并非控制性失血休克大鼠复苏效果的观察

目的 观察精氨酸血管加压素(AVP)对海水浸泡合并非控制性失血休克大鼠的复苏效果.方法 采用15℃低温海水联合脾切除的非控制性失血休克Sprague-Dawley(SD)雄性大鼠72只,14～16周龄,体重(230±20)g,按随机数字表法将大鼠分为单纯乳酸林格液(LR)复苏对照组(LR组),去甲肾上腺素(NE)联合LR复苏组(NE组)、AVP联合LR复苏组(AVP组),各24只.休克后各实验组大鼠分别静脉输注LR、NE(5μg/kg)+LR以及AVP(0.1U/kg)+LR.观察AVP对休克大鼠失血率、复苏液体量、凝血功能、酸中毒及存活的影响.结果 经海水浸泡合并非控制性失血休克后,在彻底止血前低压复苏阶段AVP组失血率(49±3.6)％较LR组大鼠失血率(52±6.0)％减少,NE组失血率较LR组增加.确定性治疗阶段AVP组复苏液体量(32.9±2.23)mL较LR组复苏液体量(66.7±5.63)mL显著降低(P<0.01),NE组复苏液体量(47.0±3.50)mL减少,但与LR组比较无显著差异(P>0.05).复苏结束后,AVP组凝血功能显著改善,表现为凝血酶原时间国际化比值(PT-INR)、凝血酶原时间(PT)较LR组显著缩短(P<0.05,P<0.01),分别为(2.0±0.11)s和(23.2±1.20)s;NE组凝血功能改善不显著(P>0.05).血气分析提示各组大鼠pH值均恢复至7.3左右,AVP组氧分压(PaO2)较LR组和NE组有一定程度增加,至(153.0±14.49)mmHg.AVP组平均存活时间显著延长至26h,24h存活率为50％;NE组和LR组平均存活时间分别为20h和16h,24h存活率均仅为25％.结论 AVP能显著减少海水浸泡合并非控制性失血休克大鼠的失血率和输液量,改善凝血功能和血气,延长存活时间,提高存活率.     

限制性液体复苏对非控制性失血性休克大鼠肠系膜淋巴循环的影响

目的 观察早期不同速度液体复苏对肠系膜淋巴循环的影响,了解限制性液体复苏的机制. 方法 健康雄性SD大鼠46只,失血+断尾法建立非控制性失血性休克(uncontrolled hemorrhagic shock,UHS)模型.将动物按随机数字表法分为假手术对照组(10只)、UHS模型组(12只)、快速复苏组(12只)和限制性复苏组(12只).快速复苏组及限制性复苏组分别以5 ml·kg-1·min-1及1 ml·kg-1·min-1的速度输注乳酸林格液(LR),肠系膜主淋巴管插管收集淋巴液.记录淋巴液流量,检测血浆及淋巴液中蛋白浓度、内毒素及TNF-α的含量. 结果 复苏60 min时,快速复苏组和限制性复苏组淋巴液流量分别为(4.04±0.33) ml·kg-1·h-1和(1.79±0.18) ml·kg-1·h-1(P＜0.01);快速复苏组和限制性复苏组蛋白输出量分别为(80.5±10.2) mg·kg-1·h-1和(43.1±9.6) mg·kg-1·h-1(P ＜0.01).复苏240 min时,快速复苏组和限制性复苏组淋巴液内毒素含量分别为(1.36 ±0.41)EU/ml和(0.81±0.26) EU/ml(P＜0.01).复苏120 min时,快速复苏组和限制性复苏组淋巴液中TNF-α含量分别为(3.86±0.23) ng/ml和(2.63±0.52) ng/ml(P ＜0.05). 结论 UHS导致肠系膜淋巴循环障碍,限制性液体复苏可以改善肠系膜淋巴循环.     

Controversies in cervical spine imaging in trauma patients

No area of emergency radiology has generated as much discussion in recent years as the subject of cervical spine imaging for trauma patients. This review will be in three parts. The first will examine the indications for cervical imaging and will focus on those factors that make patients at high risk or low risk for cervical injury. The second part will discuss the merits of radiography and computed tomography as the main screening diagnostic examination. In addition to the roles of each modality in the evaluation process, such factors as efficacy of diagnosis, time (duration) of study, and cost will be discussed. Finally, the third part will explore the methods currently employed to clear the cervical spine in comatose patients.Presented at the Annual Meeting of the American Society of Emergency Radiology, Las Vegas, Nevada, 22–25 October, 2003     

Influence of in vivo copper on MR images of the liver in rats

To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

Brodie Abscess: MR imaging appearance in 10 patients

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic “target” appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypoin-tense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.     

Interventional procedures in the upper urinary tract

The introduction and acceptance of percutaneous nephrostomy as a safe and effective alternative to surgical nephrostomy served as the impetus for the development and expansion of an ever-increasing number of techniques that are encompassed by the term “interventional uroradiology.” This article reviews many of the non-vascular interventional techniques that have proliferated during the past decade and that are currently used in the kidney, ureter, and perinephric space. The authors emphasize those procedures that are most frequently employed, as well as their own preferences and perspectives on these procedures.     

Imaging in spinal trauma

Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given.     

MR imaging of blood oxygenation-dependent changes in focal renal ischemia and transplanted liver tumor in rat

The potential of using fast magnetic resonance (MR) imaging in conjunction with apnea-induced blood deoxygenation for the noninvasive monitoring of relative perfusion in the rat abdomen has been studied with two experimental models: glycer-ol-induced focal renal ischemia and transplanted liver tumor. Gradient-echo echo-planar imaging (GRE-EPI) (TE of 20 msec at 2 T) of liver and kidney was performed before, during, and after a 60-second apnea episode and then was followed in the same rat by contrast-enhanced (a) GRE-EPI and (b) T1-weighted spin-echo imaging (TR msec/TE msec = 200/6) with polylysine-(gadolmium-DTPA [diethylenetriaminepentaacetic acid]). The results indicate that a noninvasive vascular challenge due to apnea can be used for the detection of focal tissue perfusion abnormalities in rat kidney and liver tumor.