浅低温心脏不停跳心内直视手术215例临床分析

目的：总结215例浅低温体外循环下不停跳心内直视手术的临床应用经验。方法：215例行心脏不停跳心内直视手术病例,并行循环者阻断上下腔静脉而不阻断升主动脉,不使用心脏停跳液;逆行灌注者,阻断升主动脉后经冠状静脉窦逆行持续灌注机器氧合血,鼻咽温度在（33±1）℃,均在心脏空跳下完成心内直视手术。结果：心脏手术完毕后顺利停机,术后血液动力学平稳,低心输出量综合征发生率低,无1例发生神经系统并发症及空气栓塞,早期死亡率0．93％（2／215）。结论：浅低温体外循环下不停跳心内直视手术技术安全可行,是一种接近生理状态的心肌保护方法,可应用于绝大部份心内直视手术。     

老年患者浅低温心脏不停跳瓣膜置换中的心肌保护

背景:体外循环心内直视手术引起的心肌损害是术后并发症发生的重要原因,浅低温心脏不停跳技术有明显的心肌保护作用,对某些高危患者尤为有益.目的:观察浅低温体外循环心脏不停跳瓣膜置换对老年患者的心肌保护作用.方法:选择年龄≥60岁择期行二尖瓣人工瓣膜置换的风湿性心脏病患者30例,根据治疗方式分为2组,停跳组在中度低温心脏停跳下完成心脏瓣膜置换,不停跳组在浅低温心脏跳动中完成心脏瓣膜置换.结果与结论:在转机30 min、术中关闭右心房前,两组患者肿瘤坏死因子α、白细胞介素6,8、心肌肌钙蛋白Ⅰ浓度较转机前时升高(P < 0.05),其中以停跳组明显(P < 0.05).关闭右心房时两组核转录因子κB的表达增加,以不停跳组增加幅度较小(P < 0.05).提示浅低温心脏不停跳技术可以减轻老年患者体外循环心内直视手术过程中的心肌损害,该作用可能与减轻心肌的局部炎症反应有关.     

不阻断升主动脉75例心内直视手术观察与监护

自１９９５年７月至１９９６年２月，我院采用浅低温（３２－２８℃）体外循环不阻断升主动脉心内直视下，行各种先天性心内畸形矫治术及瓣膜置换术７５例。该手术与阻断升主动脉相比其优越性在于，一采用浅低温，降温升温时间缩短，体外转机时间缩短，相应手术时间也缩短。二不阻断升主动脉，心脏不停跳，避免再灌注损伤，保护心肌。因此，对机体的病理生理改变影响减少，所致术后临床表现与阻断升主动脉术后临床表现有所不同。主要以术后１－２小时出现短时间的体温低，血压低，尿量少，心率加快表现为重点，加以观察与监护。     

心脏不停跳心内直视手术治疗先天性心脏病62例

目的 总结心脏不停跳心内直视手术矫正先天性心脏病心内畸形的经验.方法 62例病人均常规建立体外循环,降温到31～35℃左右,阻断上下腔静脉,不阻断主动脉,心脏跳动下施行心内畸形矫正术.结果 全组无死亡病人,随访2个月恢复良好.结论 心脏不停跳下心内直视手术有较好的心肌保护作用,减少了并发症,缩短体外循环时间,是一种安全实用的手术方法.     

不阻断升主动脉75例心内直视手术观察与监护

自１９９５年７月至１９９６年２月，我院采用浅低温（３２－２８℃）体外 阻断升主支沁内直视下，行各种先天性心内畸形治术及瓣膜置换术７５例。该手术与阻断升主动脉相比共优越性在于，一采用浅低温、降温升地间缩短；体外转机时间缩短，相应手术时间也缩短。二不阻断升主动脉，心脏不停跳，避免再灌注损伤，保护心肌，因此，对机体的病理生理改变影响减少，所致术后临床表现有所不同。主要以术后１－２小时出现短时间的体温低，     

浅低温体外循环心脏不停跳下心内直视手术的临床应用

目的：通过测定心脏不停跳与心脏停跳手术两组患者的血浆肌钙蛋白（cTn—Ⅰ）值以及心肌活检．评价心脏不停跳手术对心肌保护的效果。方法：选择40例心脏病患者于浅低温体外循环心脏不停跳下心内直视手术作为实验组，同期选择40例于低温心脏停跳下心内直视手术作为对照组，测定两组患者术前、术中、术后各时相的cTn—Ⅰ值，以及心肌活检病理进行比较研究。结果：两组术前cTn—Ⅰ值和心肌活栓病理显示心肌超微结构差异无显著性（P〉0．05）；转机后两组cTn—Ⅰ值均升高，对照组比实验组增高明显，差异有显著性（P〈0．05）：而心脏活检病理显示心肌超微结构上实验组优于对照组，差异有显著性（P〈0．05）。结论：浅低温体外循环心脏不停跳手术可明显减轻心肌缺血再灌注损伤．对心肌起到良好的保护作用     

浅低温体外循环心脏跳动二尖瓣置换术对心肌保护的体视学研究

目的用体视学定量法对比分析两种二尖瓣置换术（MVR）对心肌超微结构的影响，旨在为浅低温体外循环心脏不停跳心内直视手术对心肌保护效果作进一步客观的评价。方法将40例风湿性心脏病二尖瓣病变患者随机分为两组进行手术，20例在浅低温体外循环心脏不停跳下行MVR（不停跳组），20例在中低温冷血停搏液灌注心脏停跳下行MVR（停跳组）。两组均分别于体外循环前后切取少许心肌组织，用计算机图像分析系统对心肌超微结构的体视学定量进行对比分析。结果两组线粒体各参数在转流前差异无显著性（P均〉0.05）。停跳组在转流中、后线粒体平均直径（-↑Dmit）、平均截面积（-↑Amit）较转流前增大，但体密度（Vmit）、面数密度（Namit）、比表面（δmit）较不停跳组减少，差异均有显著性（P〈0.05或P〈0.01）；两组肌原纤维体密度（Vvmyo）在转流前、转流中变化不大，差异均无显著性（P均〉0.05），而转流后停跳组肌原纤维Vvmyo、比表面（δmyo）均较不停跳组减少，差异有显著性（P〈0.05和P〈0.01）。结论浅低温体外循环心脏跳动中心内直视手术是一种较接近生理状态的心肌保护方法，能最大程度地减轻心肌缺血、缺氧损伤，避免再灌注损伤，最大程度地保护心肌细胞形态结构的完整性，从而获得较理想的心肌保护效果。     

浅低温体外循环心脏不停跳心内直视术后的监护——附30例报告

1引言 浅低温(31℃～34℃)体外循环心脏不停跳下完成心内直视手术具有不阻断心肌血流、心肌缺血和再灌注损伤程度轻的特点,是一种新兴的最接近生理状态的心肌保护措施[1].然而,术后监护对保证病人术后康复、减少并发症亦十分重要.我科自1998年10月～1999年12月共完成浅低温体外循环心脏不停跳心内直视手术30例,临床效果满意,现将术后监护体会报告如下.     

心脏不停跳心内直视手术对心肌保护作用的临床研究

浅低温心脏不停跳心内直视手术能够缩短心肌缺血时间,我们将此方法与低温心脏停跳心内直视手术进行了对比研究,旨在探讨不停跳心内直视手术对心肌的保护作用,为临床应用提供理论依据。1对象和方法1．1研究对象实验组（心脏不停跳心内直视手术组）10例,男3例,女7例;年龄20±15．5岁;其中房间隔缺损3例,空间隔缺损3例,二尖瓣置换3例,部分性心内膜垫缺损1例。同期选择16例病人作为对照组（低温心脏停跳心内直视手术组）,男6例,女10例;年龄18±12.6岁;其中房间隔缺损3例,室缺9例,二尖瓣置换3例,主动脉窦瘤1例。1．2研究方法1．…     

浅低温不停跳心内直视手术的体外循环管理探讨

目的探讨浅低温不停跳下心内直视手术的体外循环管理。方法回顾性分析我院78例不停跳心内直视手术的体外循环资料,观察患者的一般情况,体外循环时间,转机中血压、尿量、血气分析、停机时患者的心率、心律、血压、术后并发症等。结果78例患者均平稳完成体外循环,术后无严重并发症,均痊愈出院。结论浅低温不停跳心内直视手术安全可靠,心肌保护良好,可有效减轻低温和缺血再灌注对心肺等脏器的损伤,术后并发症少,患者恢复快。     

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.