高频喷射通气结合胸壁挤压对组胺致肺损伤犬呼吸循环功能的影响

以高频喷射通气结合胸壁挤压（ＨＦＪＶ＋ＣＷＣ）为通气模式，观察其对组胺致肺损伤犬呼吸循环功能的影响，并与单纯高频喷射通气（ＨＦＪＶ）进行比较。结果表明：与ＨＦＪＶ相比，ＨＦＪＶ＋ＣＷＣ时的功能残气量（ＦＲＣ）、ＰａＣＯ＿２和ＰＣＯ＿２均显著降低（Ｐ＜０．０１），肺泡通气量（Ｖ＿Ａ）和二氧化碳排出量（ＣＯ＿２）均显著增高（Ｐ＜０．０１），每分呼出气量（Ｖ＿Ｅ）、ＰａＯ＿２、ＰＣＯ＿２、吸气峰压（ＰＩＰ）、平均气道压（Ｐａｗ）、呼气末压（ＥＥＰ）、ＨＲ、平均动脉压（ＭＡＰ）、肺动脉压（ＰＡＰ）和肺毛细血管楔压（ＰＣＷＰ）均无显著变化（Ｐ＞０．０５）。提示：ＨＦＪＶ＋ＣＷＣ除保留单纯ＨＦＪＶ时气道开放、气道低压、良好的血液氧合、不影响循环功能等特点外，还具有增加呼气动力，改善肺泡通气，显著促进ＣＯ＿２排除等优点。     

高低频率结合喷射通气的动物实验及临床观察

本文应用高频喷射振荡（ＨＦＪＯ）、低频喷射通气（ＬＦＪＶ）以及高频喷射振荡叠加低频喷射通气（ＨＦＪＯ＋ＬＦＪＶ）三种通气方式，观察对无自主呼吸犬的氧合及ＣＯ＿２排出的效果。三种通气方式都能维持较好的氧合，但ＨＦＪＯ＋ＬＦＪＶ能有效地排出ＣＯ＿２，防止ＣＯ＿２潴留。临床应用观察到，对于快速静脉诱导的无自主呼吸的麻醉病人，和ＨＦＪＯ相比，ＨＦＪＯ＋ＬＦＪＶ在气道内平均压无明显增加的情况下，可使病人体内ＣＯ＿２有效地排出，维持动脉血ｐＨ在正常范围。我们认为，在气道开放状态下ＨＦＪＯ＋ＬＦＪＶ能增强ＣＯ＿２的排出，维持正常的气体交换，不产生对循环的不良影响。     

一种新高频通气方法对实验性急性呼吸窘迫综合征的疗效观察

在高频喷射通气（ＨＦＪＶ）治疗犬实验性急性呼吸窘迫综合征（ＡＲＤＳ）时，采用连续ＨＦＪＶ基础上间歇叠加深吸气（ＨＦＪＶ＋ＤＩ）的新通气方法，以期为ＡＲＤＳ的治疗寻找一种新途径。用油酸复制犬ＡＲＤＳ模型，并随机分为３组。ＨＦＪＶ＋ＤＩ组（ｎ＝１０）：在连续ＨＦＪＶ基础上每隔１０分钟加入１次深吸气；常规机械通气组（ＣＭＶ，ｎ＝１０），给予０．７８５ｋＰａ（１ｋＰａ＝１０．２０ｃｍＨ２Ｏ）呼气末正压（ＰＥＥＰ）治疗；对照组（ｎ＝１０），未予通气治疗。每隔１小时测定１次氧合及血流动力学指标，共观察５小时。注射油酸后，动脉氧分压（ＰａＯ２）由１２．４００ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）降至６．５６０ｋＰａ（Ｐ＜０．０１），动脉二氧化碳分压（Ｐａ－ＣＯ２）未见明显变化。通气治疗后，ＣＭＶ和ＨＦＪＶ＋ＤＩ均使ＰａＯ２明显升高，ＰａＣＯ２无明显变化（Ｐ＞０．０５），ＨＦＪＶ＋ＤＩ的氧释放指数（ＤＯ２Ｉ）明显高于ＣＭＶ组（Ｐ＞０．０５），心脏指数（ＣＩ）在ＣＭＶ组及ＨＦＪＶ＋ＤＩ组均明显减低（Ｐ＜０．０５）。提示：ＨＦＪＶ＋ＤＩ时ＰａＯ２的提高大于ＣＩ下降所致的不利影响，在改善组织缺氧方面明显优于ＣＭＶ时加用ＰＥＥＰ     

高频双向喷射通气和常规机械通气对蒸气吸入性损伤犬治疗效果的比较

目的：观察高频双向喷射通气（ＨＦＴＪＶ）和常规机械通气（ＣＭＶ）对蒸气吸入性损伤犬的呼吸循环动力学参数、肺容量及血气的影响。方法：通过蒸气吸入致伤，复制了犬重度蒸气吸入性损伤模型。结果：①两种通气方式下呼吸系统总阻力（Ｒｒｓ）、肺阻力（ＲＬ）均显著高于对照值（Ｐ均＜０．０１），呼吸系统总顺应性（Ｃｒｓ）、肺顺应性（ＣＬ）均显著低于对照值（Ｐ均＜０．０５），但两者之间比较，Ｒｒｓ、ＲＬ和Ｃｒｓ、ＣＬ的变化均无显著性差异（Ｐ均＞０．０５）。②ＣＭＶ能引起ＣＯ２潴留；ＨＦＴＪＶ比ＣＭＶ显著增加ＣＯ２排出量（ＶＣＯ２，Ｐ＜０．０５），降低过高的ＰａＣＯ２（Ｐ＜０．０１）。③两种通气方式下功能残气量（ＦＲＣ）、心输出量（ＣＯ）、平均动脉压（ＭＡＰ）和ＰａＯ２均无显著变化（Ｐ均＞０．０５）。结论：两种通气方式均能克服气道阻力辅助呼吸，但不能使伤后高气道阻力和低肺顺应性恢复正常。ＣＭＶ的通气效率较低，可引起ＣＯ２潴留；ＨＦＴＪＶ的通气效率则明显优于ＣＭＶ，且能维持吸入性损伤犬的血气至正常水平。     

两种通气时动脉血与呼气末二氧化碳分压的关系

本文选用ＡＳＡ分级Ⅰ级病人１０例，全麻下随机用ＩＰＰＶ（潮气量８～１０ｍｌ／ｋｇ，吸∶呼＝１∶２，呼吸频率１４次／分）和ＨＦＪＶ（压力０．１ＭＰａ，频率６０～８０次／分）各先后通气３０分钟，抽取通气３０分钟时的动脉血做血气分析，比较此时的ＰａＣＯ２和ＰＥＴＣＯ２。发现ＩＰＰＶ时ＰａＣＯ２为５．３８±１．３７，ＰＥＴＣＯ２４．３６±０．８３，ＨＦＪＶ时，ＰａＣＯ２为５．５５±２．０３，ＰＥＴＣＯ２为３．６８±０．９５。无论在ＩＰＰＶ或ＨＦＪＶ时，ＰａＣＯ２与ＰＥＴＣＯ２存在正相关关系（ｒ分别为０．８０７和０．６９）。并求出相应的回归方程。在临床上，通过无创性ＰＥＴＣＯ２监测，可间接判断ＰａＣＯ２，及时发现和处理呼吸机和呼吸管理中出现的问题。提高全麻病人和使用呼吸机病人的安全性。     

开放式高频喷射通气在重症烧伤患者应用中的评价

目的：对开放式高频喷射通气（ＨＦＪＯＶ）用于重症烧伤患者长期呼吸支持的效果、并发症和预后进行评价。方法：分析９７例重症烧伤患者持续应用ＨＦＪＯＶ辅助通气当日、第２天、第６天或第１０天以上的疗效，根据显效、有效和无效３种标准予以判定。结果：ＨＦＪＯＶ使用当日总有效率６５．０％，第２天后疗效进行性降低，至第１０天后仅３１．８％（Ｐ＜０．０１）。呼吸道损伤出血是最常见和最严重的并发症，ＨＦＪＯＶ使用６天后，发生率从５６．７％升至８１．８％（Ｐ＜０．００１）；而后为呼吸性碱中毒、血或痰块引起的气道阻塞和呼吸性酸中毒。呼吸功能衰竭仍然是主要死因。结论：由于气道开放，ＨＦＪＯＶ技术难以实施湿化、温化、灭菌、氧浓度监测和调节；因此，长时间使用ＨＦＪＯＶ可能使通气效率降低，引起气道损伤；ＨＦＪＯＶ无效或须应用４天以上时，应更换其它通气支持方式；对严重肺损伤患者，ＨＦＪＯＶ不宜作为首选的呼吸支持方式。     

体外膈肌起搏治疗慢性阻塞性肺病呼吸衰竭的疗效

报告体外隔肌起搏（ＥＤＰ）治疗慢性阻塞性肺病（ＣＯＰＤ）。结果：１１慢性肺心病重度Ⅱ型呼衰者应用ＥＤＰ后ＰａＯ＿２无明显提高（Ｐ＞０．４），ＰａＣＯ＿２明显降低（Ｐ＜０．０５）。２６例肺心病轻度Ⅱ型呼衰者应用ＥＤＰ后ＰａＯ＿２明显升高（Ｐ＜０．００１），ＰａＣＯ＿２明显降低（Ｐ＜０．００１）。１５例肺心病Ⅱ型呼衰者应用ＥＤＰ加高频喷射通气（ＨＰＪＶ）后，ＰａＯ＿２明显升高，ＰａＣＯ＿２增高不显著（Ｐ＞０．０５）。３２例ＣＯＰＤ者应用ＥＤＰ治疗（３０ｍｉｎ／ｄ）３０天后，ＰａＯ＿２、ＰａＣＯ＿２、肺活量（ＶＣ），每分通气量（ＭＶ）和６分钟步行距离（６ＭＤ）明显改善。表明ＥＤＰ是ＣＯＰＤ的有效康复疗法，但对肺心病严重Ⅱ型呼衰患者无效。     

联合应用同步间歇指令通气和压力支持通气抢救格林－巴利综合征呼吸衰竭

采用联合同步间歇指令通气（ＳＩＭＶ）和压力支持通气（ＰＳＶ）方式抢救１１例格林－巴利综合征（ＧＢＳ）呼吸衰竭患者。通气前：ｐＨ为７．２２±０．０８，ＰａＣＯ＿２为８．０２±０．５２ｋＰａ（６０．３０±３．９１ｍｍＨｇ），ＰａＯ＿２为６．０６±０．２５ｋＰａ（４５．５６±１．８８ｍｍＨｇ）；联合通气后：ｐＨ为７．３９±０．０４（Ｐ＜０．０５），ＰａＣＯ＿２为５．５４±０．３１ｋＰａ（Ｐ＜０．０１），ＰａＯ＿２为９４０±０．２６ｋＰａ，（Ｐ＜０．０１）。心电图Ｓ－Ｔ段及Ｔ波异常明显好转。治愈９例，好转２例。结果表明：ＳＩＭＶ和ＰＳＶ联合运用能改善患者有效通气而不增加呼吸功，减少因机械通气而发生的氧中毒和呼吸性碱中毒，对循环系统无损害作用。     

高频喷射通气加综合方案治疗Ⅱ型呼吸衰竭临床研究

高频喷射通气加综合方案治疗Ⅱ型呼吸衰竭临床研究周生明（山东新汶矿务局莱芜医院，新汶２７１１０３）自１９８６年以来，我们在实验研究基础上［１，２］，采用高频喷射通气（ＨＦＪＶ）加促使ＣＯ２排出的综合方案治疗肺心病Ⅱ型呼吸衰竭（Ⅱ ＲＦ）４９例，疗效满意...     

应用无死腔气管插管提高正常和急性肺损伤兔的机械通气效率

目的：观察无死腔气管插管能否提高急性呼吸衰竭常规机械通气的效果。方法：应用一种新型无死腔气管插管和普通聚氯乙烯气管插管对正常和急性肺损伤兔进行常规通气，对两种气管插管的肺气体交换和气道内气体动力学及血流动力学变化进行比较。无死腔气管插管用２根Ｐｏｔｅｘ气管插管远端３ｃｍ处纵切后对粘而成。５只新西兰成年兔，麻醉下气管切开，在持续应用潘龙阻断自主呼吸条件下，随机用新型气管插管和普通气管插管Ｓｅｒｖｏ９００Ｃ进行机械通气，每次持续３０分钟，测定并记录动脉血压、气道压力、血流动力学参数和呼气末ＣＯ２浓度。结果：在正常肺和急性肺损伤条件下，新型气管插管可使所有动物的ＰａＣＯ２和生理死腔／潮气量（ＶＤ／ＶＴ）下降，ＰａＣＯ２分别下降１．４０±０．２０ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）和１．６０±０．３０ｋＰａ（Ｐ＜０．０１），ＶＤ／ＶＴ分别下降０．１３±０．０２和０．１５±０．０４（Ｐ＜０．０１）；ＰａＯ２、气道压力和血流动力学无显著变化。结论：无死腔气管插管可明显提高常规机械通气效率。     

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.