血液生化检测各阶段质控影响因素的探讨

目的:探析血液生化检测各阶段质控的影响因素。方法:选择2014年2月-8月期间我院收治的行血液生化检测患者60例为研究对象,对其临床检验资料进行回顾性分析。结果:有诸多因素会影响血液生化检测各阶段质控,其中以年龄、标本采集处理、检测仪器、性别以及药物作用等为主。结论:血液生化检测各阶段质控受到诸多因素的影响,相关检验人员一定要严格按照操作,从检测前、中、后加强质量控制,使出现误差的几率降低,从而有效提高血液生化检验结果的可靠性和精确性,为临床治疗提供有效保障。     

临床检验生化分析的前质量保证探析

目的:分析影响临床检验生化分析前质量的相关因素,总结保证生化检验前质量的相关对策。方法:选取2012年4月~2014年4月在我院进行生化检验的病历资料,对其生化检验分析过程中发生的差错进行回顾性分析,总结影响生化检验分析前质量的相关因素。结果:出现生化检验差错的148例病例中,64.19%发生在分析前,23.65%发生在分析中,112.16%发生在分析后。在影响分析前质量的各项因素中,采样不规范所占比例最高,其次为样本送检不及时,另外患者准备不当、样本处理欠妥也是影响检验分析前质量的主要因素。结论:生化检验分析的前质量会受到多种因素影响,生化检验科应加强前质量管理、控制,以确保检验结果的准确,从而为临床诊断、治疗提供可靠依据。     

关于两种全自动生化分析仪校准周期的对比研究

目的:对日立H7180、奥林帕斯Au640全自动生化分析仪校准周期的对比分析。方法:相同条件下,两生化分析仪进行定标校准后,每隔2小时测定高、中、低3种浓度的质控血清各一次直到24 h,后每间隔24 h测定一次,共测定30 d,检测项目均重复测定4次取平均值。从校准完成后开始计时到累积变异系数(CV)大于1/6 CLIA'88允许误差时终止,确定该项目的校准周期。通过绘制校准周期图获得两种全自动生化分析仪不同检测项目的校准周期,并对结果进行对比分析。结果:以碱性磷酸酶(ALP)为例绘制校准周期图,进行对比分析。各检测项目在日立H7180中,低水平质控CV最先达到校准要求,高水平质控CV最后达到校准要求;而在奥林帕斯Au640中,中水平质控CV最先达到校准要求,高水平质控CV最后达到校准要求。结论:日立H7180和奥林帕斯Au640全自动生化分析仪,其校准周期基本一致,个别项目存在差异。     

科学确立奥林帕斯Au640 全自动生化分析仪校准周期

目的:利用校准周期图科学确立奥林帕斯Au640全自动生化分析仪校准周期。方法:生化分析仪定标校准后,每隔2小时分别测定三种浓度水平的质控血清一次,24小时后每天测定一次,总计测定30天。所有检测项目均重复测定四次取平均值。以积变异系数(CV)大于1/6 CLIA’88为评价标准,绘制校准周期图。结果:碱性磷酸酶(ALP)L1校准周期最短每12 h一次。酶类项目较稳定,校准周期可达30天以上,低水平质控血清必不可少,这样有利于测得更为准确的校准周期。结论:科学、合理地确立各检测项目的校准周期,对生化分析仪检测系统进行定期校准,既能够避免不必要的校准、又能够节省检验工作的时间和成本,保证生化检验项目检测结果可靠性。     

普通外科切口感染危险因素分析

目的:研究普外科切口感染的危险因素。方法:对本院自2012年3月~2013年7月本院进行普外科手术800例患者研究,其中发生感染患者有36例,回顾性探究普外科手术切口感染的主要危险性因素。结果:根据本院的回顾性研究,普通外科切口的感染例数所占的百分比率为4.5%,I类切口患者有326例,II、III类切口例数为474例,其中I类切口感染例数为6例,所占百分率为1.84%,II、III类切口感染例数为30例,所占百分率为6.36%。造成切口感染危险因素与年龄、肥胖、性别、糖尿病、切口分类、手术性质、手术时间等相关。结论:通过加强对普外科切口感染危险因素的监控,可以有效的降低普外科切口发生感染的概率。     

对目前医院检验科生化质控管理工作的现状与改进措施研析

目的:探讨目前医院检验科生化质控管理工作的现状与改进措施。方法:分析我院90例进行生化检验患者,对患者进行常规检查,对生化检验中质控管理情况进行分析,并提出相关改进措施。结果:经过调研,进行生化检查的90例患者中,样品治疗有出现污染现象15例,不合格率为16.67%;门诊质控管理差。结论:检验生化治疗管理在当前的管理过程中还存有较多问题,分析目前医院检验科生化质控管理工作的现状,提出相应的改进措施。     

宫颈癌患者液基细胞学与组织学诊断的比较分析 仇

目的:通过对液基细胞学检测(TCT)与组织学活检的比较分析,探讨TCT出现漏诊的原因。方法:收集83例宫颈癌患者的宫颈活检组织蜡块和宫颈脱落细胞标本,组织蜡块行常规病理切片检查,脱落细胞标本进行TCT检测。结果:和组织病理学诊断结果比较,这些患者的TCT诊断漏诊18例。进行过抗HPV治疗的宫颈癌患者,其TCT漏诊率明显高于未治疗者(P<0.05)。结论:TCT在宫颈癌筛查中存在一定的漏诊,其产生的原因与癌细胞分化程度、宫颈糜烂程度、非诊断细胞的干扰、不当的采集方法及抗HPV治疗有关。     

患者参考样本用于生化自动分析仪室内质控监测的探讨

目的:探讨患者参考样本在生化自动分析仪室内质控检测中的意义。方法:选取就诊患者新鲜血液2-3ml作为血清样本,采用自动生化分析仪对其进行检测。结果:采用不同模式进行检测产生的偏倚程度不同。偏倚程度与测定物质的稳定性、时间延长等因素有关。结论:抽取了患者具有稳定性的新鲜血清作为控制检测的样本,并按时对仪器的运行结果进行仔细观察,做好记录,在更多时间点对试剂和仪器进行监测,能够保证随机质量控制及全程质量控制的目的。     

儿童化学发光免疫分析中稀释方法的探讨

目的:探讨儿童化学发光免疫分析中标本量过少时,用怎样的稀释介质以及稀释方法解决这个问题,分析不同的稀释介质产生的基质效应。方法:本实验以儿童常规筛查检测项目血清三碘甲状腺原氨酸(TT3)为例,选取血清样本30例,分别使用美国贝克曼库尔特公司UniCel DXI800 Access化学发光免疫分析仪测试药盒三碘甲状腺原氨酸(TT3)配套TT3定标液S0(简称TT3S0)、0.9%氯化钠、医用蒸馏水作为稀释介质进行手工2倍(1:1)及4倍(1:3)后测定。计算稀释测定结果与原始数据的差异,观察基质效应对检测结果的影响。寻找实际工作中可运用的稀释介质和稀释倍数。结果:不同稀释组与原始值之间比较,TT3S02倍(t=0.7937,P0.05)、4倍稀释(t=-0.2503,P0.05),以及蒸馏水2倍稀释(t=-0.2845,P0.05)差异均无统计学意义。而0.9%氯化钠2倍(t=-6.4686,P0.05)、4倍稀释(t=-3.9842,P0.05),以及医用蒸馏水4倍稀释(t=-1.9957,P0.05)差异有统计学意义。结论:三碘甲状腺原氨酸TT3S0定标液2倍,4倍稀释方法及医用蒸馏水2倍稀释方法均可以得到较为满意的结果。三碘甲状腺原氨酸(TT3)配套TT3定标液S0可用于标本2倍及4倍稀释。当定标液获取困难,蒸馏水2倍稀释同样可以运用。     

两种方法检测血糖的差异

目的:探讨罗氏ADVANTAGE优越血糖仪与迈瑞-820全自动生化分析仪检测血糖的可比性,为临床提供可靠数据。方法:随机选取本院就诊血糖测定患者,血糖仪标本为静脉血全血,采血后立即测试,血糖仪试条为随机附带,仪器用质控液校正,生化仪为同一标本,采血后2 h内测试,血清是静脉血抽取后离心分离。结果:通过对127例血糖仪与全自动生化分析仪的血糖检测结果进行对比分析,表明两种检测方法在检测血糖中差异无显著(P0.05)。结论:在血糖仪的测定范围内,两种方法都是可靠的,但血糖仪测定范围受限,过高或过低时无数据显示,生化仪会补血糖仪之不足。     

Improving the accuracy of death certification

BACKGROUND: Population-based mortality statistics are derived from the information recorded on death certificates. This information is used for many important purposes, such as the development of public health programs and the allocation of health care resources. Although most physicians are confronted with the task of completing death certificates, many do not receive adequate training in this skill. Resulting inaccuracies in information undermine the quality of the data derived from death certificates. METHODS: An educational intervention was designed and implemented to improve internal medicine residents'' accuracy in death certificate completion. A total of 229 death certificates (146 completed before and 83 completed after the intervention) were audited for major and minor errors, and the rates of errors before and after the intervention were compared. RESULTS: Major errors were identified on 32.9% of the death certificates completed before the intervention, a rate comparable to previously reported rates for internal medicine services in teaching hospitals. Following the intervention the major error rate decreased to 15.7% (p = 0.01). The reduction in the major error rate was accounted for by significant reductions in the rate of listing of mechanism of death without a legitimate underlying cause of death (15.8% v. 4.8%) (p = 0.01) and the rate of improper sequencing of death certificate information (15.8% v. 6.0%) (p = 0.03). INTERPRETATION: Errors are common in the completion of death certificates in the inpatient teaching hospital setting. The accuracy of death certification can be improved with the implementation of a simple educational intervention.     

Calibration characteristics of a video dimension analyser (VDA) system.

A comprehensive calibration and error analysis of a video dimension analyser (VDA) system was carried out to determine the effects of various parameters relevant to actual test conditions on the characteristics of the system. The parameters considered were: (1) varying distances or angles between the test specimen and the camera; (2) refractive effects of glass tank and physiologic solutions; and (3) dynamic response of the VDA system. The error analysis shows that, at low strain levels, the strain computed by the VDA is sensitive to camera placement and orientation as well as the media through which the object is observed. Very large errors can occur at small nominal strains, depending on the system parameters (e.g. 80% error at 1% nominal strain for one set of parameters). At higher strain levels, the sensitivity of the system is reduced, and the strain computed by the VDA system approaches the nominal strain (10% error at 10% nominal strain).     

Influence of loading rate and cable migration on fiberoptic measurement of tendon force

Several investigators have recently used fiberoptic cables to measure tendon forces in situ. The technique may be subject to significant error due to cable migration and differences in the loading rates used for calibration and those experienced during measurement. This in vitro study examined the impact of these potential sources of error on transducer accuracy. A fiberoptic cable was passed perpendicular to the fibers of four Achilles tendons in the mediolateral direction and each specimen was cyclically loaded to 1000 N. The influence of loading rate on transducer output was investigated by comparing results from tests conducted at 20, 200 and 1000 N/s. The effect of cable migration was examined by comparing the outputs obtained after displacing the cable one tendon width medially and laterally along its path in the tendon and then repeating the 200 N/s testing protocol. It was possible to obtain nonlinear specimen-specific relationships between the fiberoptic output and tendon force. Differences in loading rate resulted in root-mean-square (RMS) errors not larger than 17% maximum load. Hysteresis effects caused RMS errors smaller than 5% maximum load. Cable migration errors were less than 27%. The total RMS error due to the combined effects of loading rate difference and cable movement was less than 32%. Fiberoptic measurement of tendon force is attractive due to its low cost, easy implementation and comparable accuracy relative to other implantable force transducers. Although additional factors such as cable placement, edge artifacts due where the transducer exits the skin and non-uniform loading may also influence fiberoptic output, careful control of loading rate and transducer movement during calibration is imperative if maximum accuracy is to be achieved.     

Errors in microdensitometry

Summary Microdensitometric errors can originate in the instrument, in the specimen or in the human operator. Instrumental sources of systematic error mostly reduce the apparent integrated absorbance, especially of relatively small and highly absorbing objects. They can be assessed, minimized or eliminated by available techniques, but with modern apparatus are in general important only if results of high accuracy are required. Instrument errors include: (a) distributional error, due to the use of too large a measuring spot or the specimen being out of focus; (b) glare (stray light), due mainly to multiple reflections in the microscope objective; (c) monochromator error (the use of insufficiently pure light); (d) calibration errors; and (e) errors resulting from lack of photometric linearity, or the specimen absorbance exceeding the measuring range of the instrument.Specimen errors, including problems of stain specificity and stoichiometry, are now the most important obstacles to a wider use of microdensitometry in histochemistry. The following selected topics are briefly discussed: fading; rate of staining; Beer's law deviations and the microdensitometry of opaque particles.Human errors include faulty logic, and failing to attempt an investigation because of anticipated difficulties which are in fact exaggerated or imaginary. The significance of microdensitometric results should, in general, be assessed by biological criteria rather than merely statistically; the use is urged of appropriate internal biological controls and standards wherever possible.     

An algorithm for automated analysis of ultrasound images to measure tendon excursion in vivo

The accuracy of an algorithm for the automated tracking of tendon excursion from ultrasound images was tested in three experiments. Because the automated method could not be tested against direct measurements of tendon excursion in vivo, an indirect validation procedure was employed. In one experiment, a wire "phantom" was moved a known distance across the ultrasound probe and the automated tracking results were compared with the known distance. The excursion of the musculotendinous junction of the gastrocnemius during frontal and sagittal plane movement of the ankle was assessed in a single cadaver specimen both by manual tracking and with a cable extensometer sutured to the gastrocnemius muscle. A third experiment involved estimation of Achilles tendon excursion in vivo with both manual and automated tracking. Root mean squared (RMS) error was calculated between pairs of measurements after each test. Mean RMS errors of less than 1 mm were observed for the phantom experiments. For the in vitro experiment, mean RMS errors of 8-9% of the total tendon excursion were observed. Mean RMS errors of 6-8% of the total tendon excursion were found in vivo. The results indicate that the proposed algorithm accurately tracks Achilles tendon excursion, but further testing is necessary to determine its general applicability.     

A suggestion for computing objective function in model calibration

A parameter-optimization process (model calibration) is usually required for numerical model applications, which involves the use of an objective function to determine the model cost (model-data errors). The sum of square errors (SSR) has been widely adopted as the objective function in various optimization procedures. However, ‘square error’ calculation was found to be more sensitive to extreme or high values. Thus, we proposed that the sum of absolute errors (SAR) may be a better option than SSR for model calibration. To test this hypothesis, we used two case studies—a hydrological model calibration and a biogeochemical model calibration—to investigate the behavior of a group of potential objective functions: SSR, SAR, sum of squared relative deviation (SSRD), and sum of absolute relative deviation (SARD). Mathematical evaluation of model performance demonstrates that ‘absolute error’ (SAR and SARD) are superior to ‘square error’ (SSR and SSRD) in calculating objective function for model calibration, and SAR behaved the best (with the least error and highest efficiency). This study suggests that SSR might be overly used in real applications, and SAR may be a reasonable choice in common optimization implementations without emphasizing either high or low values (e.g., modeling for supporting resources management).     

应用溶血指数探讨溶血对多个生化项目的干扰情况

目的:探讨标本溶血对生化项目检测结果的影响,并使用溶血指数对影响程度进行量化,并探讨其临床意义。方法:总蛋白(TP)、尿酸(UA)、肌酸激酶(CK)、乳酸脱氢酶(LDH)、总胆红素(TBIL)均参考美国临床实验室标准化委员会(CLSI)制定的评价方案EP7-A2文件的标准程序,每个项目收集20份新鲜混合血清(TBIL<17.1μmol/L和TBIL>150μmol/L分别收集),包括参考值范围内的10份、低值和高值各5份,每份新鲜混合血清用3~4份入选血样混合成约8 mL。每份新鲜混合血清分成若干份,分别与洗涤好红细胞配制的溶血液制成5个不同浓度的溶血模型(试验组)及与之配对的无溶血模型(对照组),然后分别测定试验组、对照组及分出的1份混合血清原样的血红蛋白浓度,并在罗氏cobasC501全自动生化分析仪上测定3次所需项目和溶血指数,计算血红蛋白浓度与溶血指数之间的关系,以及溶血对TP、UA、CK、LDH、TBIL检测结果影响的大小。参考EP7-A2文件的统计方法,计算最大允许偏差对应的干扰物浓度,以每份测试混合血清的溶血指数为x轴、其对应的检测项目变化值(干扰值)为y轴绘制干扰曲线。结果:对每项目20份混合血清的660个测试、5个项目3960检测结果用假设检验统计,TP、CK、LDH、TBIL(<17.1μmol/L和>150μmol/L)的μ值分别为4.42、2.34、2.20、2.76、2.93,P值均小于0.05,说明溶血对TP、UA、CK、LDH、TBIL均存在显著干扰。通过回归分析统计出不同溶血程度的溶血指数值对应的干扰变化值的干扰剂量反应曲线。TP、CK、LDH、TBIL的干扰剂量回归方程分别为y=0.0099x-0.065、y=0.1001x-2.42、y=1.1406x-1.3303、y=1.78×10-5x2-0.011x-0.235、y=1.88×10-5x2-0.048x-4.169。从干扰剂量反应曲线可看出溶血对LDH、CK、TP检测产生正干扰,对TBIL检测产生负干扰。同时发现溶血对UA结果的干扰很不稳定,即溶血对尿酸检测结果存在正干扰及负干扰,这一结果得到相关文献印证。结论:溶血指数可作为标本是否合格的客观指标,避免主观判断的误差;利用测得的溶血指数,可从干扰剂量曲线或回归方程求出检测结果的变化值,使临床通过干扰曲线判断溶血对检测项目产生的影响,从而做出准确客观的判断。     

不同麻醉方式处理休克病人的46 例临床研究

目的：观察并分析对休克病人实施不同的麻醉处理方式的临床效果。方法：选取2012 年2 月至2013 年2 月我院收治的临 床休克患者46 例，选择性的实施不同的麻醉方式进行处理。比较患者麻醉前后各项监测指标的变化情况。结果：实施麻醉术后， 有43 例患者表现为正常；2 例因大出血抢救无效而死亡；1 例因多器官功能发生衰竭而死亡；术中未发生因麻醉不当而导致的患 者死亡。术后生命体征正常的患者明显高于死亡的患者，差异有统计学意义(P＜0.05)。患者手术之后各项指标显著优于手术前，差 异有统计学意义(P＜0.05)。结论：对临床休克病人采取合适的麻醉方式，可以有效的辅助手术顺利进行，提高手术的成功率和患 者的存活率，值得临床推广。     

良性中心气道狭窄支气管镜介入治疗术后近远期再狭窄相关因素分析

目的探讨良性中心气道狭窄支气管镜介入治疗术后近远期再狭窄相关因素。方法对2011年2月~2015年2月我院收治的60例良性中心气道狭窄患者经支气管镜下介入治疗,治疗方式包括高频电刀、冷冻、球囊扩张、金属覆膜支架置入等。治疗后对患者的治疗时机、局部感染情况、治疗方法、气道狭窄病因、年龄、性别、基础疾病等情况进行分析,随访观察评估术后疗效、出现再狭窄的时间,探讨近远期再狭窄的危险因素。结果 Cox回归分析表明,患有基础疾病(高血压、糖尿病)、球囊扩张、支架置入、治疗时机不当(溃疡坏死增值阶段)、局部感染是良性气管狭窄支气管镜下腔内介入治疗术后近期再狭窄的相关危险因素,其对再狭窄影响的风险比(OR值)依次为6.715、2.197、5.820、6.914、5.345。支架置入和治疗时机不当(溃疡坏死增值阶段)是良性气管狭窄支气管镜下腔内介入治疗术后远期再狭窄的相关危险因素,其对再狭窄影响的风险比(OR值)分别为6.706,7.154。结论良性中心气道狭窄患者支气管镜下腔内介入治疗术后近期再狭窄的危险因素是基础疾病、球囊扩张、支架置入、局部感染、治疗时机不当,远期再狭窄危险因素是支架置入和治疗时机不当。