AVL血气分析仪pH值测定结果的可比性探讨

目的通过对2台AVL血气分析仪pH值测定结果进行比对和偏倚评估,探讨pH值测定的可比性,为减少测定结果偏差提供实验数据。方法参考美国临床实验室标准化委员会（NCCLS）的EP9-A2文件,以AVL COMPACTⅢ血气分析仪、原装定标液和质控品组成系统为比较方法,AVL COMPACTⅡ为实验方法,计算实验方法（Y）与比较方法（X）之间的系统误差（SE）,以美国临床实验室修正法规（CLIA＇88）规定的室间质量评价允许误差1/2（0.02 pH值单位）为标准,判断不同仪器测定结果的可比性。结果在电极保养或更换电极（膜）后,偏差超范围标本由8.29%降为1.71%。结论用2台血气分析仪同时检测时,应及时进行保养和偏倚评估,保证检验结果的可比性,为临床提供最佳服务。     

AVL compact3与Bayer248血气分析仪检测结果的对比研究

目的通过对AVL compact3和Bayer248 2台血气分析仪测定结果进行比对评估,为减少测定结果偏差提供实验数据。方法依据美国临床实验室标准化委员会EP9-A文件要求,每天随机抽取8例患者动脉血标本,标本包括高、中、低3种水平,同时在AVL compact3和Bayer248 2台血气分析仪上对分析直接对pH值、氧分压(PO2)和二氧化碳分压(PCO2)进行测定,连续测定5 d。结果经SPSS10.0软件进行配对t检验行差异性分析。并计算线性回归方程和方法间的系统误差,以美国临床实验室修正法规建议的医学决定水平处的系统误差来判定两种仪器之间的可比性。另用质控品进行精密度、准确度试验。结果 40份标本分析得到相同的趋势结果,pH值、PO2和PCO2检测结果差异无统计学意义(P>0.05)。各检测项目医学决定水平处的系统误差均在允许误差内。且质控品批内变异系数小于1.0%。2台血气分析仪均具有高精密度及准确度。结论 2台仪器精密度、准确度间差异均在临床可接受范围内,相关性良好,均可向临床提供准确一致的报告。     

即刻床旁血气分析仪与中心实验室血气分析仪的一致性评价

目的 评价即刻床旁血气分析仪与实验医学科临床生化实验室血气分析仪测定结果的一致性.方法 参考医疗机构临床实验室管理办法和临床实验室标准协会(CLSI)提出的比对建议设计比对方案,对血气分析直接测定的指标pH值,氧分压(PO2)和二氧化碳分压(PCO2)进行分次比对,使用SPSS11.0软件进行F检验,分析多台仪器之间差异,并参照各项目的 临床总允许误差(TEa).结果 三个项目中,每台仪器测定结果间的差异均无统计学意义(P>0.05),即刻床旁血气分析仪与临床生化实验室血气分析仪PCO2的测定结果绝对偏差小于1/2 TEa,pH值比对结果绝对偏差小于TEa,PO2测定结果的绝对差值大部分不在TEa范围内.结论 pH值和PO2存在系统偏差,需调试即刻床旁检测仪并对病房使用即刻床旁检测仪器相关人员进行规范化培训,才能有效控制分析前的变异,以保证POCT与中心实验室测定结果的一致性.     

雅培 i-STAT 与 AVL CPMPACT3血气分析仪检测结果的可比性分析

目的：探讨雅培 i-STAT 血气分析仪与 AVL CPMPACT3血气分析仪检测结果的可比性。方法以 AVL COM-PACT3血气分析仪作为参考系统,以雅培 i-STAT 血气分析仪作为待测系统,对比分析2个检测系统测定 pH、氧分压（PO2）、CO2分压（PCO2）等项目的一致性。结果2个检测系统重复测定质控品 pH、PO2、PCO2的变异系数（CV）均小于其对应的1/2允许总误差（TEa）。2个检测系统测定 pH、PO2、PCO2的检测结果差异无统计学意义（P ＞0．05）。2个检测系统测定 pH、PO2、PCO2在不同医学决定水平（Xc）处的系统误差（SE ）均小于其对应的1/2TEa。结论AVL COMPACT3血气分析仪与雅培 i-STAT 血气分析仪检测患者样本结果具有可比性,可以向临床提供一致的报告。     

不同检测系统电解质测定结果的正确度性能评价

目的评价IMS972电解质分析仪与强生Vitros-350生化分析仪两种测量方法测定钾(K)、钠(Na)、氯(Cl)3项之间的偏倚,并确定其偏倚是否在可接受的范围内。方法根据美国临床实验室标准化协会(NCCLS)的EP9-A2文件,以IMS972电解质分析仪为比较方法,强生Vitros-350生化分析仪为实验方法,测定K、Na、Cl 3个项目,分别以美国临床实验室修正法规(CLIA′88)规定允许误差的1/2作为评价标准和生物学变异导出的分析质量目标作为可接受标准,分析两种分析仪测定结果之间的相关性和偏倚,评估测定结果之间的可比性。结果两种分析仪检测K+、Na+、Cl-结果具有较好的一致性,预期偏倚可以接受。结论不同分析仪检测同一项目时,需进行方法学比对实验作出偏倚评估,确保检测结果的一致性。     

不同全自动生化分析仪血脂检测实验比对和偏倚评估

目的探讨AU5400和AU2700全自动生化分析仪血脂指标检测结果是否具有可比性。方法依据美国临床和实验室标准化协会(CLSI)EP9-A2文件,以美国临床实验室修正法规(CLIA′88)对室间评估允许误差的1/2为临床可接受依据,评价2台生化分析仪血脂指标检测结果的可比性。结果 2台分析仪血脂指标检测结果具有较好相关性(r>0.975),相对偏差均符合CLIA′88要求。结论应对不同分析系统相同指标检测结果进行比对分析及偏倚评估,判断其一致性,以保证检测结果的可比性。     

两台生化分析仪检测结果的可比性评价

目的 通过对同一临床实验室不同生化分析系统进行方法比对和预期偏差评估,探讨不同生化分析系统之间检测结果是否具有可比性和检测结果的偏差是否在允许的范围内.方法 按照美国临床实验室标准化协会(CLSI)EP9-A文件要求,以奥林巴斯AU400为参比检测系统,迈瑞BS300为待评检测系统,每天取8份新鲜血清标本,分别用奥林巴斯AU400生化分析仪和迈瑞BS300生化分析仪2套检测系统测定标本天冬氨酸氨基转移酶(AST)、肌酸肌酶(CK)、尿素(UREA)、尿酸(UA)、血糖(GLU)含量,共测定5 d,记录检验结果,计算相关系数(r)、回归方程以及预期偏倚,并对偏倚进行分析评估.结果 两检测系统的测定结果有良好的可比性.结论 相同项目在同一临床实验室不同生化分析系统测定时,至少每半年应对其进行方法对比和偏差评估,对预期偏差不能接受的项目应采取相应的改进措施.     

同室2台全自动生化分析仪常规项目检测结果比对和偏差评估

目的通过对本实验室OLYMPUS AU640和BECKMAN AU5821全自动生化分析仪部分项目检测结果进行比对和偏差评估,探讨2台生化分析仪检测结果是否具有可比性。方法参考美国临床实验室标准化委员(NCCLS)的EP9-A2文件要求,分别在2台仪器上测定新鲜临床混合血清和质控血清,以OLYMPUS AU640为参考仪器,BECKMAN AU5821作为比对仪器,利用相关回归分析和配对t检验对相同项目的检测结果进行比对和偏差评估,以美国临床实验室改进修正案能力验证(CLIA′88)允许总误差的1/2为标准,评价检测结果是否具有可比性。结果 2台生化分析仪的大部分检测结果具有较好的一致性。结论通过对不同生化分析仪测定结果进行比对和偏差分析,可以验证相同项目检测结果间的相关性,有助于对仪器评价、校正,以满足临床需求。     

血细胞分析仪两种模式检测结果比对分析和偏倚评估

目的通过对BC-1800血细胞分析仪全血模式和预稀释模式进行方法比对和预期偏倚评估,探讨两种模式之间检测结果是否具有可比性,或检测结果的偏差是否在允许范围内。方法依据美国国家临床实验室标准化协会EP9-A2文件要求,以全血模式为比较方法,预稀释模式为实验方法,对白细胞(WBC)、红细胞(RBC)、血红蛋白(Hb)和血小板(PLT)进行方法学比对、相关性分析和预期偏倚估计,判断偏倚是否可以接受。结果所有项目均具有良好的相关性(r≥0.75),预期偏差均未超出允许偏差范围,偏倚可以接受。结论在严格按照操作规程做好质控的基础上,BC-1800血细胞分析仪两种模式对WBC、RBC、Hb和PLT的检测结果具有可比性。     

不同生化分析仪测定结果的比对分析及偏倚评估

目的通过对本科室OLYMPUS AU5400与罗氏Cobas c311生化分析仪的比对分析和预期偏倚评估,探讨两台生化分析仪之间的检测结果的可比性,以保证检测结果的准确。方法按照美国临床实验室标准化协会(CLSI)EP9-A2文件的要求,以OLYMPUS AU5400生化分析仪作为比较方法,罗氏Cobas c311生化分析仪作为实验方法,用患者血清对AST、CK等7个项目进行检测,在医学决定水平处计算其系统间的偏倚,以美国CLIA’88规定的允许误差的1/2作为标准进行评估。结果所测定的7个项目的回归系数r均大于0.975,两台仪器在医学决定水平处的预期偏倚和相对偏倚均小于1/2 CLIA’88的允许误差。结论AST、CK等7个项目在两台生化分析仪上的检测结果是一致的,具有可比性。     

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.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.