人血清标准物质在改进临床实验室T-Bil测量结果正确度中的价值研究

摘要：目的：研究人血清标准物质对改进临床实验室总胆红素（T-Bil）测量结果正确度的价值。 方法：以北京市12家临床实验室血清T-Bil常规测量系统为例,分别用常规测量系统同时测量人血清T-Bil国家一级标准物质GBW09184、GBW09185,评价测量结果的正确度;再以GBW09184代替常规系统校准品重新测量GBW09185,分析各常规测量系统测量结果的正确度。分别用测量结果计量学可溯源、统计学可接受及临床可接受3个判断标准评价各常规系统测量结果的正确度,同时分析12家实验室测量结果的变异情况。 结果：12家实验室T-Bil常规测量系统GBW09184、GBW09185标准物质测量结果分别为95.7~137.8 μmol/L、35.3～57.4 μmol/L,均值分别为116.6 μmol/L、47.7 μmol/L,偏移分别为+7.9%、+7.0%,总变异分别为10.25%、12.80%;用计量学溯源、统计学可接受、临床可接受标准判断分别有17%（2/12）、33%（4/12）、33%（4/12）的实验室测量结果正确。除4号外的其他11家实验室校准后,T-Bil常规测量系统GBW09185标准物质测量结果为40.7～57.3 μmol/L,均值为46.3 μmol/L,偏移+3.8%,总变异为9.70%;用计量学溯源、统计学可接受、临床可接受标准判断分别有36%（4/11）、64%（7/11）、64%（7/11）的实验室测量结果正确。 结论：北京市80%临床实验室T-Bil常规测量系统测量结果的正确度不能满足ISO17511的溯源要求;人血清T-Bil国家一级标准物质可明显改善各临床实验室测量结果的正确度。     

4种总胆红素检测系统的性能评价

目的评价A~D 4种总胆红素(total bilirubin,T-Bil)检测系统的分析性能。方法用美国临床和实验室标准化协会(CLSI)EP5-A2、EP15-A2、EP7-A2、EP6-A、EP9-A2文件方法评价4种T-Bil检测系统的精密度、正确度、抗干扰性、分析测量范围(AMR)及与Beckman Coulter DXC800重氮法结果的相关性和相对偏差。用美国病理学家协会(CAP)发放的室间质评物(N-A和N-B)评价D系统检测T-Bil正确度,质评物可溯源至临床化学参考方法程序定值。回归分析用Passing-Bablok法,回归线性检测用Cusum法,相关分析用Pearson相关,偏差分析用Bland-Altman法。结果 T-Bil在17~258μmol/L时,4种检测系统(A~D)的不精密度均小于各厂家声明的标准。测定CAP室间质评物显示4种检测系统的相对偏差均小于各厂家声明的标准。Hb、TG、Vit C对各系统均有不同程度干扰。AMR评价浓度分别为733.58、230.18、710.09、459.78μmol/L。A、B、C与D系统比较相关性较好,平均绝对偏差分别为-16.6、3.4、-0.8μmol/L,平均相对偏差分别为-25.32%、-3.49%、-11.75%。结论 T-Bil各检测系统间存在一定偏差,且钒酸氧化法较重氮法检测结果偏低。     

不同正确度验证方法来源的偏移对实验室σ水平的影响

正6σ质量管理方法曾被广泛的应用于世界各大企业的质量管理中。Nevalainen最早将其应用于临床实验室的质量评价当中[1-2]。目前,国内大部分文献在应用公式计算实验室σ水平时使用国家卫生计生委临床检验中心全国常规化学室间质评(external quality assessment,EQA)结果统计偏移,而偏移是反映测试正确度的指标。根据GB/T6379的定义,正确度是指由大量测定结果     

血清肌酐参考方法的建立及其在正确度调查中的应用

目的建立同位素稀释液相色谱串联质谱(ID-LC/MS/MS)测定人血清肌酐的参考方法,并运用于临床实验室正确度调查新鲜冰冻血清样本靶值的确立。方法按照国际检验医学溯源联合委员会(JCTLM)推荐方法,建立本实验室肌酐参考方法,利用参考物质SRM909c及RELA比对样本考察所建方法的精密度与准确度,并将建立的参考方法用于上海地区小分子正确度调查新鲜冰冻血清肌酐靶值的确立。结果参考方法测量参考物质SRM909c相对偏移为0.69%,测量不精密度2%,初步验证了方法的准确度和精密度。正确度调查样本201411、201412、201421、201422酶法检测结果与参考方法测定值的相对偏移分别为14.97%、-2.77%、-1.37%、-1.92%;苦味酸法检测结果与参考方法测定值的相对偏移分别为21.39%、2.10%、6.22%、2.38%。除201411样本(为低浓度样本)外,其余样本不同常规分析系统测定的血清肌酐浓度与参考方法赋值结果的相对偏移均不超过8%。结论建立的ID-LC/MS/MS测定血清肌酐的方法精密度、准确度均较好,靶值的确定对实验室检测结果分析有重要意义,该参考方法的建立有望在上海地区临床实验室正确度计划中发挥一定作用,并建议临床实验室重视低浓度下肌酐测量的准确度和一致性。     

血清尿酸参考测量程序的优化及其在常规系统中的应用

目的 优化血清尿酸参考测量程序(简称参考方法),为尿酸常规测量系统的建立提供参考。方法 建立美国临床化学协会(AACC)推荐的血清尿酸参考方法,并进行优化(离心40 min后再次离心15 min),采用美国国家标准和技术研究院(NIST)标准品SRM 909C和国际比对样本RELA20B、RELA21A进行正确度验证。通过高、中、低值临床剩余血清样本验证精密度。配置6个浓度梯度进行线性评估。采用优化后的参考方法和临床常规方法同时测量40份单人份血清样本,将2种方法检测结果进行回归分析。根据美国临床实验室标准化学会(CLSI)EP14-A3文件要求对常规方法使用的校准品进行互换性分析。比较优化前后尿酸检测结果。结果 尿酸参考方法优化前后SRM 909C、RELA20B、RELA21A的测定结果均在国际临床化学和检验医学联合会(IFCC)等效限范围内(±3.25%),SRM 909C优化前后的测量结果均在其证书范围内[(278.57±5.95)μmol/L]。优化后的重复性明显提高,实验室内精密度虽然改善不明显,但其低值精密度有很大改善,达到实验室对精密度的要求[变异系数(CV)<2...     

反相高效液相色谱紫外法检测人血清尿酸

目的探讨日本临床化学会(JSCC)推荐的检测人血清尿酸(UA)的反相高效液相色谱紫外(HPLC-UV)法是否可作为候选参考方法来验证同位素稀释质谱法、评价常规方法。方法对反相HPLC-UV法进行复现并进行方法学评价。观察尿酸酶处理人血清样本后的色谱以评价其特异性;检测系列标准液的UA水平并绘制标准曲线,观察线性范围;用朗道公司质控品评价精密度;用UA标准液评价回收率;分别用有证参考物SRM 909b(Ⅰ和Ⅱ)、国家一级标准物质GBW 09176、GBW 09175、GBW 09174评价正确度,并与2008年国际临床化学与检验医学联合会(IFCC)参考实验室RELA(ring trials for reference labora-tories)结果进行比对;用改良Bland-Altman图评价5种常规检测系统与反相HPLC-UV法间的偏差。结果尿酸酶处理后UA色谱峰消失;本法的线性范围为2.08～1 785μmol/L;批内变异系数(CV)均<0.3%,批间CV均<0.4%,日间CV均<2.3%,总CV均<2.7%;平均相对回收率为96.0%～100.6%;与SRM909bⅠ和Ⅱ靶值的偏移分别为-2.5%、-2.3%;与GBW09176、GBW 09174、GBW 09175靶值的偏移分别为0.29%,-0.74%和0.06%;与参加RELA比对的另3家实验室的平均值进行比较,水平1偏移为0.35%,水平2为-0.69%;Hitachi、Beckman Coulter、Roche、Dade、Vitros常规检测系统检测人血清UA与反相HPLC-UA法的相关系数分别为0.998 9、0.996 5、0.999 2、0.999 2和0.998 7,与反相HPLC-UA法的偏差均小于5%的生物学变异。结论本法特异、简便、快速,精密度好,正确度高,与具有良好溯源的常规测定系统具有良好的相关性和一致性,可推荐作为人血清UA测定的候选参考方法。     

三种临床血清酶国际、国内实验室比对结果分析及其参考方法的评估

目的分析2006年度至2007年度连续2年参加国际临床化学联合会（IFCC）的参考实验室丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、乳酸脱氢酶（LDH）的室间质评（RELA）结果及卫生部临床检验标准委员会（以下简称卫生部）的酶学室间比对结果,评估其所用测定参考方法的检测质量及其完善程度。方法根据IFCC公布的ALT、AST、LDH的测定参考方法的标准操作程序（SOP）进行测定,根据《分析测量中不确定度的量化》（QUAM2000）计算合成标准不确定度,用日本临床检验标准协议会（JCCLS）旭化成株式会社认证酶标准物质评估参考方法的分析性能（准确度与不精密度）。结果2006年度的国际RELA与卫生部酶学室间比对结果室内变异系数（CV）均在1．5％～2．1％,2007年度的国际RELA结果与卫生部酶学室问比对结果室内CV均在1．1％以下,且本实验室与总体均值的偏倚整体低于2006年度,除2006年度卫生部酶学室间比对结果有3个值与总体均值的偏倚（7．99％,-7．02％,-13．97％）超过允许偏倚外,其余值均在允许偏倚范围内。ALT、AST、LDH标准物质室内CV均在1％以下,且均值偏倚靶值均低于1％。结论本实验室所用测定ALT、AST、LDH的参考方法已比较成熟稳定,2007年度的实验室比对结果优于2006年度。     

双水平校准纠正苦味酸法肌酐检测偏移

目的通过临床检验实验室间质量评价(室间质评)分析苦味酸法检测肌酐的偏移及校准对偏移的影响。方法利用重庆市临床检验室间质评数据,开展冰冻混合人源血清(参考方法赋值)调查,分析苦味酸法与酶法肌酐检测结果间的差异及偏移;用双浓度水平冰冻混合人源血清(参考方法赋值)校准常规检测系统后检测室间质控品。结果 2012年至2016年重庆市苦味酸法肌酐检测实验室数下降;苦味酸法实验室稳健均值与酶法存在差异,且差值与肌酐水平有相关性(r=0.774 6);冰冻混合人源血清(参考方法赋值)调查及国家卫计委临床检验中心正确度验证结果均显示,苦味酸法肌酐在低浓度存在正偏移(最大达10.39%和13.31%),且偏移与浓度相关(r=0.988 9),而酶法肌酐的偏移较小(最大达1.04%和1.49%);用冰冻混合人源血清校准常规检测系统后,苦味酸法肌酐检测在低浓度的正偏移被抵消。结论苦味酸法肌酐检测在低值范围存在正偏移,双浓度水平校准可纠正此偏移。     

降钙素原定量检测系统的性能验证

目的对南京诺尔曼公司降钙素原(PCT)定量检测系统进行用于临床检测前的性能验证。方法收集临床标本,验证批内和总不精密度、分析测量范围、检测限、临床常见干扰物干扰性能指标,是否符合实验室质量目标或产品说明书要求,并与已得到认可的检测系统进行比对,同时进行参考区间的初步验证。结果高、中和低浓度PCT样品的批内不精密度分别为5.75%、2.79%和1.50%,总不精密度分别为6.10%、4.22%和1.67%;分析测量范围高限至少达到90.27 ng/m L;检测限为0.018 ng/m L;可抵抗类风湿因子(RF)1 380 U/L、胆红素(T-Bil)600μmol/L、溶血(Hb 10g/L)和脂肪乳(TG 20 g/L)的干扰;与Roche检测系统比对相关系数r=0.998,回归方程:Y=0.994X+0.018,医学决定水平浓度(Xc=0.5、2和10 ng/m L)的偏移可以接受(实验室质量目标PCT最大允许偏移为10%);20例无感染的健康体检者结果均在正常参考区间范围内。结论该PCT检测系统能抗常见干扰物的干扰,其精密度、正确度、分析测量范围、检测限和正常参考区间符合实验室质量要求,可用于临床样本常规检测。     

基于离子色谱技术对血清氯离子常规系统的正确度评价

目的：以离子色谱法为比对方法,评价电极法和硫氰酸汞法测定血清氯离子的正确度。方法用离子色谱法测定2011～2013年的 RELA 样本,27份新鲜单份血清和校准品中的氯离子,同时采用电极法和硫氰酸汞法在自动生化分析仪上检测血清中氯离子和校准品中的氯离子,测定结果依据 EP9-A2文件进行方法学比对进行评价。结果电极法和硫氰酸汞法与离子色谱法比对的直线方程分别为Y ＝1.0181X ＋2.2780,Y ＝0.6793X ＋34.222平均偏移分别为4.05％和1.59％。结论离子色谱法能准确测定血清中氯离子的含量。依据 EP9-A2文件,电极法与离子色谱法的正确度性能一致,硫氰酸汞法与离子色谱法的正确度性能不一致。为保证临床样本的准确测量,各厂家和临床界都急需建立常规检测项目的测量正确度评价方法来评价常规测量系统的正确度。     

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.     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.