不同透析方法对透析中低血压的预防作用

目的探讨不同透析方法对血液透析中低血压的预防。方法32例血液透析中常发生低血压的患者采用4种不同的透析方法：①高钠透析：透析治疗最初4h内用高钠透析液（透析液钠浓度150mmol／L），结束前0．5h钠浓度调至135mmol／L。②单纯超滤＋血液透析：透析最初30min单纯超滤，以后4h透析。③低温透析：整个透析过程中透析液温度调至34．5—35．5℃。④低温透析＋高钠透析。结果4种透析方式的透析效果并无差异，高钠透析、低温透析、低温＋高钠透析对于稳定血压明显优于标准透析（透析液钠浓度140mmol／L，温度37℃）组。单纯超滤＋血液透析并不能减少低血压发生率。结论本研究提示对于反复发生低血压的透析患者临床首选高钠透析、低温透析以及低温＋高钠透析。透析间期体重增加〉2．8kg的透析患者单纯超滤＋血液透析并不能降低低血压的发生率。     

应用新透析模式预防血液透析低血压的效果观察

目的 探讨阶梯式超滤联合低温可调钠透析模式在预防维持性血液透析患者透析过程中低血压发生的效果.方法 随机将32例在血液净化室行维持性血液透析,有低血压倾向且透析间期体重增加≥3kg的患者分为观察组和对照组,各16例,观察组患者行阶梯式超滤联合低温可调钠透析,对照组患者行标准透析.比较2组患者发生低血压的例次、透析中的血压和透析结束时的脱水量.结果 观察组低血压的发生例次低于对照组(p<0.05),观察组透析结束前血压高于对照组(p<0.01),观察组透析结束时实际脱水量多于对照组(p<0.01).结论 阶梯式超滤联合低温可调钠透析模式可减少透析中低血压的发生率,提高血液透析质量,减少护理工作量,节约医疗成本,是一种简单、有效、经济的措施.     

不同透析方法对透析中低血压的预防作用

目的：血液透析(HD)中低血压非常常见，有几种不同的处理方法。本研究主要探讨比较几种不同的处理方法哪个更优。方法：12例血液透析中常发生低血压的患纳入观察对象。四种不同的透析方法①高钠透析：透析治疗前4小时用高钠透析液(透析液钠浓度150mmol/L)，结束前半小时钠浓度调至135mmol／L。②单纯超滤 HD：透析开始前30分钟单纯超滤，以后4小时透析。③低温透析：整个透析中透析液温度调至34．5℃—35．5℃。④低温透析 高钠透析。结果：四种透析方式的透析效能并无差异，高钠透析、低温透析、以及低温 高钠透析对于稳定血压均明显优于标准透析(透析液钠浓度140mmol/L、温度37℃)组。单纯超滤 HD并不能减少低血压发生率。结论:本研究提示对于反复发生低血压的透析患临床首选高钠透析、低温透析以及低温 高钠透析。透析间期增重大于2．8k8的透析患，单纯超滤 HD并不能降低低血压的发生率。     

低温可调钠透析对血液透析相关低血压的影响及护理

目的 研究低温可调钠血液透析对透析低血压的影响及护理。方法 选择经常发生透析低血压的维持性血液透析患者40例,随机分为二组,观察组采用低温联合可调钠透析,对照组采用常规标准透析,观察3个月,测量患者的超滤量、血肌酐、血尿素氮、血钠、血压等指标。结果 两组透析后超滤量、血肌酐、血尿素氮、血钠均无明显差别,而低温联合可调钠透析组低血压发生率明显下降。结论 低温联合可调钠透析可以有效减少透析低血压的发生。     

血液透析107例透析期间低血压发生情况分析

目的：调查分析血液透析期间低血压的发生率及相关因素。方法：随机选择107例血液透析患者,观察其在一个透析月内低血压发生的频率,分析人口统计学及临床特征与低血压发生的相关性。结果：所有观察患者中26例患者发生了至少一次透析期间低血压,高龄、超滤量大、原发病为糖尿病者,低血压发生率较高。结论：低血压是血液透析期间的常见并发症,多种因素与其发生有相关性。     

渐进式低温可调钠透析对有低血压倾向高危患者超滤量的影响

目的：观察渐进式低温可调钠透析对有低血压倾向高危患者超滤量的影响。方法选择有低血压倾向的高危透析患者60例,随机分为常温常规组、渐进式低温可调钠组各30例,每例患者观察10次,观察比较患者透析前目标超滤量、透后超滤量、透析中低血压发生率及透析提前结束率。结果2组患者透析前目标超滤量比较,差异无统计学意义（P=0.112）;透析后超滤量、低血压发生率及透析提前结束率比较,差异均有统计学意义（P=0.000）。结论渐进式低温可调钠透析可防治透析中低血的发生、增加有低血压倾向高危患者的透后超滤量、提高患者的透析充分性,从而提高其生活质量和存活率。     

渐进式低温加可调钠透析法用于高危患者透析的效果观察

目的 观察渐进式低温加可调钠透析在防治高危患者透析低血压的有效性和安全性.方法 选择有低血压倾向的高危透析患者25 例,采用自身对照方法,随机分别进行10 次常温常规透析、低温可调钠透析、渐进式低温加可调钠透析,观察比较3 种方法血液透析过程中,血压值、超滤量和不良反应发生率及低血压发生率的差异.结果 透析中、透析后,3 组的收缩压、舒张压、超滤量比较差异有统计学意义(P＜0.001),低温可调钠法、渐进式低温可调钠法优于常温常规法;低温可调钠法、渐进式低温可调钠法透析低血压发生率明显低于常温常规法(P＜0.001);渐进式低温可调钠法患者的透析不良反应发生率,明显低于低温可调钠法和常温常规法(P＜0.001).结论 低温可调钠透析、渐进式低温可调钠透析可明显减少维持血液透析中高危患者的低血压发生率,但渐进式低温加可调钠透析更安全,适合有低血压倾向的高危透析患者,且温度可安全控制至35～34℃,明显减少透析不良反应发生率.     

透析致低血压患者低温联合钠及超滤曲线透析的护理观察

目的 探讨低温联合钠及超滤曲线透析模式对患者透析致低血压的影响.方法 选择40例连续4次血液透析中出现低血压≥2次的维持性血液透析患者,以抽签法随机分为观察组和对照组各20例.对照组给予常温常规透析模式;观察组给予低温联合钠及超滤曲线透析模式,比较两种模式下患者的血压变化、相关并发症发生情况、体温变化、超滤量及血钠浓度情况.结果 观察组透析过程中最低血压值为(102.05±5.88)/(64.10±4.63)mmHg(1 mmHg=0.133 kPa),较对照组最低血压值(89.00±4.81)/(57.20±4.91)mmHg有明显增高(P<0.05);观察组较对照组低血压、肌肉抽搐、头晕恶心呕吐等并发症发生情况明显减少(P<0.05或P<0.01);两组超滤量、透析前后血钠浓度比较差异无统计学意义(P>0.05);两组患者体温透析过程中较透析前均有不同程度升高,对照组透析过程中体温较观察组升高更为明显,差异有统计学意义(P<0.01).结论 低温联合钠及超滤曲线透析模式较常规常温透析模式能有效维持透析血压,减少透析相关并发症的发生,降低透析过程中的体温升高,同时可达到常规透析时的超滤量与钠平衡,值得临床推广应用.     

低温可调钠透析对老年血液透析病人低血压的影响

[目的]探讨低温可调钠透析在老年血液透析低血压痛人中的应用效果。[方法]选择行维持性血液透析中经常出现低血压反应的老年病人20例，随机分为观察组和对照组各10例，观察组接受低温可调钠透析，对照组接受常规标准透析。观察6周，分别测量病人超滤量、血肌酐、尿素氮、血钠以及血压等指标。[结果]两组透析后超滤量、血肌酐、尿素氯、血钠比较，差异无统计学意义（P〉0．05），但观察组透析中最低收缩压、舒张压和平均动脉压显著高于对照组（P〈O．05或P〈0．01）。[结论]低温可调钠透析可保持透析过程血压稳定，有效降低透析性低血压的发生。     

三种超滤模式对透析相关性低血压影响的研究

目的探讨联机血容量监测(BVM)对评价透析患者干体重和防治透析患者低血压的作用。方法选择血液透析过程中发生过1次或1次以上低血压的维持性透析患者30例,分为3组,分别采用恒定超滤、阶梯式超滤和血容量监测(BVM)控制超滤三种超滤模式进行血液透析,观察并记录患者超滤量、血压的动态变化及出汗、肌肉痉挛、头疼等不良反应的发生次数,记录护理干预次数,比较三种超滤模式透析不良反应的差异。结果与恒定超滤组、阶梯式超滤组相比,BVM控制超滤组低血压发生率、护理干预次数、血液透析中不良反应发生率明显较少(P(0.05),透析后血压显著降低(P(0.05);恒定超滤组低血压发生率、护理干预次数、血液透析中出汗、肌肉痉挛的发生率显著低于阶梯式超滤组(P0.05)。结论 BVM控制的超滤模式有助于减少血液透析中低血压的发生,并有助于评估患者的干体重。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.