D-二聚体阴性急性肺栓塞二例误诊讨论

目的探讨D-二聚体阴性急性肺栓塞(acute pulmonary embolism,APE)的临床特点。方法对误诊为其他疾病的D-二聚体阴性APE 2例的临床资料进行回顾性分析。结果 2例均以胸闷就诊,查血D-二聚体阴性。例1既往有冠状动脉粥样硬化性心脏病,误诊为充血性心力衰竭;例2因胸部CT检查结果误诊为肺部感染,均予相关治疗后症状未见好转。为进一步明确诊断,均行双下肢静脉彩色多普勒超声及CT肺动脉增强扫描,确诊为APE伴下肢静脉血栓形成,予抗凝等对症治疗后症状缓解出院。随访均未见病情复发。结论临床遇及胸闷伴D-二聚体阴性的患者,要考虑到APE可能,进一步行相关检查,以早期诊断,减少误诊误治,改善预后。     

血浆D-二聚体在肺栓塞患者中的诊断意义

目的:探讨快速定量检测D-二聚体在诊断肺栓塞患者中的临床价值。方法:检测、分析21例经螺旋CT或肺动脉造影确诊的肺栓塞患者及19例健康人(对照组)的血浆D-二聚体含量。结果:与对照组比较,肺栓塞组D-二聚体含量明显升高,有显著性差异(P<0.01)。结论:肺栓塞患者D-二聚体含量明显升高,敏感性为100%,阴性预测值为100%,检测D-二聚体可作为诊断肺栓塞的首选筛选试验。     

D-二聚体阴性肺血栓栓塞症临床分析

目的对D-二聚体阴性肺血栓栓塞症(PTE)病例与D-二聚体升高者进行对比分析。方法螺旋CT肺动脉造影(CTPA)确诊的42例PTE患者进行回顾性分析,包括性别、年龄、危险因素、临床表现、心电图、血气分析、下肢静脉及心脏超声、D-二聚体值测定、发病至就诊时间等。结果 D-二聚体值:D-二聚体阴性组(313.91±132.96)ng/L,D-二聚体升高组为(1 711±2 182.76)ng/L。发病至就诊时间:D-二聚体阴性组(9.73±3.80)d,D-二聚体升高组(5.10±2.90)d,两组相比差异有统计学意义(P<0.05)。临床各种表现对比两组无明显差异,均以呼吸困难为最常见表现,达80%以上。危险因素对比:D-二聚体阴性组高龄增多。辅助检查结果对比:D-二聚体阴性组超声心动图阳性发现率高。结论 D-二聚体测定应该与临床表现等相结合,如高度怀疑肺栓塞,特别是超声心动图发现基础病难以解释的右心负荷加重,则应进一步做CTPA等相关检查,以减少漏诊和误诊。     

D-二聚体阴性肺栓塞四例误漏诊临床分析

目的总结D-二聚体阴性肺栓塞的临床特点,分析误漏诊原因。方法对我院收治的D-二聚体阴性肺栓塞4例临床资料进行回顾性分析。结果本组2例因呼吸困难、胸闷入院,1例因双下肢水肿、疼痛伴肌肉疲劳入院,1例因咳嗽、咳痰、活动后气促入院。诊断为慢性阻塞性肺疾病2例,冠心病、下肢深静脉血栓各1例,误漏诊3~10 d,后均经螺旋CT肺动脉造影(CTPA)检查、D-二聚体检测、动脉血气分析等确诊为D-二聚体阴性肺栓塞,予华法林或低分子肝素等治疗,后病情好转出院。随访3~6个月,均预后较好。结论临床应加强对D-二聚体阴性肺栓塞的认知及鉴别诊断,以减少或避免误漏诊的发生,提高诊治水平,改善预后。     

D-二聚体定量检测在肺栓塞早期诊断中的临床价值

目的探讨全自动凝血分析仪定量快速检测D-二聚体含量在肺栓塞诊断中的临床价值。方法对经螺旋CT、MRI或肺动脉造影等确诊的26例肺栓塞患者以及25例健康人（对照组）的血浆D-二聚体定量快速检测结果与对照组相比。结果急性PE患者肺栓塞D-二聚体含量明显升高,差异有统计学意义（P〈0．01）。结论肺栓塞患者血浆D-二聚体含量显著升高,敏感性为92％,阴性预测值为100％,D-二聚体快速定量检测可作为诊断肺栓塞的首选筛选试验,可在临床中推广。     

D-二聚体阴性排除肺栓塞的临床价值

目的:了解D-二聚体阴性排除肺栓塞的临床价值。方法:回顾性分析CT肺动脉造影确诊肺栓塞患者60例血清D-二聚体水平。结果:以乳胶凝集法测定的D-二聚体诊断肺栓塞敏感率仅73.3%,阴性排除误诊率达26.7%。结论:D-二聚体阴性不一定能排除肺栓塞,需结合临床和所使用的检测方法。     

超声检查与血浆D-二聚体在脑卒中患者下肢静脉血栓诊断中的价值

目的分析超声检查与血浆D-二聚体浓度诊断脑卒中患者下肢静脉血栓形成的价值。方法对95例脑卒中患者行下肢静脉超声检查与血浆D-二聚体浓度测定,判断有无下肢静脉血栓形成。结果D-二聚体和超声检查诊断下肢静脉血栓的敏感性、特异性、阳性预测值、阴性预测值、准确性分别为80．0％、76．2％、38．7％、95．3％、76．8％和86．6％、98．8％、92．8％、97．5％、96．8％。超声诊断的特异性、准确性及阳性预测值高于血浆D-二聚体浓度测定（P〈0．05）。结论血浆D-二聚体浓度可作为临床排除静脉血栓形成的可靠指标,超声检查对于诊断脑卒中患者下肢静脉血栓具有较高的诊断价值。     

36例急性肺栓塞临床分析

目的：探讨急性肺栓塞（PTE）患者的临床表现、诊断和治疗。方法：对36例PTE患者资料行回顾性分析。结果：90％的患者PTE临床可能性测评分数〉6分。47％的患者伴下肢深静脉血栓,77％的患者存在低氧血症,97％的患者D-二聚体升高,78％的患者超声心动图示肺动脉压升高。结论：PTE患者症状和体征临床表现不完全一致,其最常见诱因为下肢深静脉血栓形成,对疑诊的患者应进行PTE临床可能性测评,常规筛查心电图、血气分析、血液生化、D-二聚体及超声心动图,高度怀疑者进一步检查肺部螺旋CT增强扫描及肺动脉造影。r-TPA静脉溶栓及低分子肝素及华法林抗凝治疗效果良好。     

超声联合D-二聚体检测在脊髓损伤患者下肢静脉血栓诊断中的意义

目的 探讨超声联合D-二聚体检测在脊髓损伤患者下肢静脉血栓诊断中的意义.方法 选取Wells评分≥3分的57例脊髓损伤患者作为研究对象,患者术后1周行下肢床旁超声检查、D-二聚体检测及静脉造影.以静脉造影结果为金标准,观察超声检查、D-二聚体检测以及二者联合检测的结果,计算并比较3种检查方法的灵敏度、特异度、准确度、阳性预测值和阴性预测值.结果 超声联合D-二聚体检测诊断静脉血栓的灵敏度(97.7％)、准确度(91.2％)和阴性预测值(90.9％)高于单独超声检查和单独D-二聚体检测,差异有统计学意义(P＜0.017),但3种方法的特异度、阳性预测值比较,差异无统计学意义(P＞0.017).超声检查的灵敏度、特异度、准确度、阴性预测值、阳性预测值与D-二聚体检测比较,差异无统计学意义(P＞0.05).结论 超声联合D-二聚体检测在脊髓损伤患者下肢静脉血栓的诊断中具有重要意义,可显著提高诊断的灵敏度、准确度和阴性预测值,从而为临床早期治疗静脉血栓提供依据.     

14例D-二聚体阴性急性肺栓塞临床分析

血浆D-二聚体(D-dimer)是交联纤维蛋白在纤溶系统作用下产生的可溶性降解产物,是一个特异性的纤溶过程标记物,其水平增高反映体内高凝状态和继发纤溶活性增强.D-二聚体对急性肺栓塞(acute pulmonary embolism,APE)诊断的敏感度高,目前普遍认为其阴性水平对急性肺血栓栓塞症有很大的排除诊断价值.我国2001年肺栓塞指南也指出,若血浆D-二聚体含量低于500 μg/L,可基本除外急性肺血栓栓塞症[1].然而,临床中仍常可见D-二聚体阴性的患者最后确诊为APE[2-3],近来更有大样本量研究发现D-二聚体阳性和阴性的疑似患者最后确诊为肺栓塞的比例差异无统计学意义[4-5].这表明D-二聚体阴性作为急性肺栓塞的排除诊断指标有待进一步研究.     

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.