CA-510全自动血凝仪的临床应用

目的：探讨CA-510全自动血凝仪应用于临床检验结果的准确性。方法：收集120例患者,抽取新鲜静脉血浆,分别应用日本Sysmex公司CA-510全自动血凝分析仪及美国IL公司ACL Advance全自动血凝分析仪进行检测。比较两仪器检测凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、凝血酶时间（TT）和纤维蛋白原（Fbg）指标的结果。结果：两台血凝分析仪检测PT,APTT,TT和Fbg指标结果比较,差异无统计学意义。结论：应用CA-510全自动血凝仪检查患者凝血指标结果可靠,对临床诊断出血、血栓性疾病、正确给予治疗措施并观察其治疗效果具有重要的意义。     

Coagulometer international sensitivity index (ISI) derivation,a rapid method using the prothrombin time/international normalized ratio (PT/INR) Line: a multicenter study

Summary. Background: The original WHO procedure for prothrombin time (PT) standardization has been almost entirely abandoned because of the universal use of PT coagulometers. These often give different international normalized ratio (INR) results from the manual method, between individual makes of instruments and with instruments from the same manufacture. Method A simple procedure is required to derive local INR with coagulometers. The PT/INR Line method has recently been developed using five European Concerted Action on Anticoagulation (ECAA) certified plasmas to derive local INR. This procedure has been modified to derive a coagulometer PT/INR Line providing International Sensitivity Index (ISI) and mean normal PT (MNPT) for coagulometers and give local INR. Results have been compared with conventional ISI calibrations at the same laboratories. Results: With human thromboplastins, mean ISI by local calibration was 0.93 (range: 0.77–1.16). With the PT/INR Line, mean coagulometer ISI was higher, for example 0.99 (0.84–1.23) but using the PT/INR Line derived MNPT there was no difference in local INR. Between‐centre INR variation of a certified validation plasma was reduced with human and bovine reagents after correction with local ISI calibrations and the PT/INR Line. Conclusion: The PT/INR Line–ISI with its derived MNPT is shown to provide reliable local INR with the 13 different reagent/coagulometer combinations at the 28 centres in this international study.     

Automated processing of whole blood samples for the determination of immunosuppressants by liquid chromatography tandem-mass spectrometry.

BACKGROUND: Liquid chromatography tandem-mass spectrometry (LC-MS/MS) is an efficient technology for routine determination of immunosuppressants in whole blood; however, time-consuming manual sample preparation remains a significant limitation of this technique. METHODS: Using a commercially available robotic pipetting system (Tecan Freedom EVO), we developed an automated sample-preparation protocol for quantification of tacrolimus in whole blood by LC-MS/MS. Barcode reading, sample resuspension, transfer of whole blood aliquots into a deep-well plate, addition of internal standard solution, mixing, and protein precipitation by addition of an organic solvent is performed by the robotic system. After centrifugation of the plate, the deproteinized supernatants are submitted to on-line solid phase extraction, using column switching prior to LC-MS/MS analysis. The only manual actions within the entire process are decapping of the tubes, and transfer of the deep-well plate from the robotic system to a centrifuge and finally to the HPLC autosampler. Whole blood pools were used to assess the reproducibility of the entire analytical system for measuring tacrolimus concentrations. RESULTS: A total coefficient of variation of 1.7% was found for the entire automated analytical process (n=40; mean tacrolimus concentration, 5.3 microg/L). Close agreement between tacrolimus results obtained after manual and automated sample preparation was observed. CONCLUSIONS: The analytical system described here, comprising automated protein precipitation, on-line solid phase extraction and LC-MS/MS analysis, is convenient and precise, and minimizes hands-on time and the risk of mistakes in the quantification of whole blood immunosuppressant concentrations compared to conventional methods.     

Automated colorimetric determination of 2,3-diphosphoglycerate

An automated colorimetric method for the determination of 2,3-diphosphoglycerate is described. The automated method is accurate when compared with Krimsky's¹ manual technique. It is highly reproducible with a sample rate of 20 tests per hour. Concentrations of substrate and enzyme are low, being of the same order as those required for the fluorimetric determination of 2,3-diphosphoglycerate. Baseline irregularity and drift have been successfully eliminated.     

Quality control in hematology

A quality control (QC) protocol for hematology, as for other sections of the laboratory, should encompass both internal and external QC programs. The extent to which a hematology laboratory should be involved depends upon various factors, including availability of facilities, financial resources, range of tests, workload, the number of staff and their levels of training, and the overall organization of the laboratory. To ensure quality patient care, the intralaboratory QC program must include at least the minimal measures of monitoring and control at each step from collection of blood specimens, through the actual processing and analysis, to reporting of the results. The protocol should be written concisely and in simple language; the procedure manual should offer all of the pertinent information along with references; all concerned personnel should be well trained and competent; and adequate facilities and time should be available for the purpose of QC. Continuing education is also an integral part of an effective QC program. Three very important aspects of QC in hematology are calibration of automated instruments, monitoring of accuracy and precision of instruments and procedures, and verifying the reliability of test results. In the absence of a true primary reference/standard for calibration of instruments for the CBC, the most commonly performed hematologic test, the use of commercial calibrators is acceptable. A combination of commercial controls (three levels) and retained or fresh patient blood specimens is recommended for monitoring of accuracy and precision on a long- and short-term basis. Patient red-cell indices moving average data allow continuous monitoring of instrument performance and should be used as an adjunct to other QC approaches to detecting instrument calibration drift. Correlation of results of related parameters and careful review of blood films remain the two most important and widely used approaches to ensure reliability of results obtained from automated hematology instruments. Participation in an external QC program offers the most practical means of monitoring overall work performance in comparison with instrument, method, and/or reagent-based peer group data. A laboratory may choose to participate in one or more national and/or regional QC programs, depending upon the range of tests it performs and the requirements of accreditation and regulatory agencies. Most of the accreditation agencies require participation in programs covering at least all of the routinely or frequently performed tests and, if available, also in those for infrequently performed tests.(ABSTRACT TRUNCATED AT 400 WORDS)     

孕中期孕妇凝血功能检测的临床意义

目的探讨孕中期孕妇凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(FIB)、抗血酶Ⅲ(ATⅢ)、蛋白C(PC)、蛋白S(S)、纤维蛋白降解产物(FDP)和D二聚体(DD)检测的临床意义。方法PT、APTT、TT、Fib测定均为凝固法,所有指标均由SYSMEXCA-1500全自动血凝仪进行测定。结果对55例孕中期孕妇(实验组)与55例正常非妊娠妇女(对照组)的凝血功能进行比较分析。孕中期孕妇组PT、APTT、TT、Fib、ATⅢ、PC、PS、FDP和DD值与对照组比较差异有显著性(P<0.01)。结论在妊娠中期孕产妇凝血功能发生了显著变化,表现为妊娠相关的高凝血状态和存在血栓并发症风险,孕产妇需要监测凝血功能。     

Practical recommendations for the use of coagulometers

The paper describes the basic stages of operation on APH2-02, APH2-02-P, and APH4-02-P coagulometers. The operating sequence is considered when carrying out the prothrombin test, the most common coagulology test in the laboratories of Russia. In addition, recommendations are given, which allow the most typical errors to be avoided.     

Staged reflexive artificial intelligence driven testing algorithms for early diagnosis of pituitary disorders

BackgroundSellar masses (SM) frequently present with insidious hormonal dysfunction. We previously showed that, by utilizing a combined reflex/reflecting approach involving a laboratory clinician (LC) on common endocrine test results requested by non-specialists, and subsequently adding further warranted tests, previously undiagnosed pituitary disorders can be identified. However, manually employing these strategies by an LC is not feasible for wider screening of pituitary disorders.ObjectiveThe aim of this study was to compare the accuracy and financial impact of an Artificial Intelligence (AI) based, fully computerized reflex protocol with manual reflex/reflective intervention protocol led by an LC.MethodsWe developed a proof-of-concept AI-based framework to fully computerize multi-stage reflex testing protocols for pituitary dysfunction using automated reasoning methods. We compared the efficacy of this AI-based protocol with a reflex/reflective protocol based on manually curated retrospective data in identifying pituitary dysfunction based on 12 months of laboratory testing.ResultsThe AI-based reflex protocol, as compared with the manual protocol, would have identified laboratory tests for add-on that either directly matched or included all manual add-on tests in 92% of cases, and recommended a similar specialist referral in 90% of the cases. The AI-based protocol would have issued 2.8 times the total number of manual add-on laboratory tests at an 85% lower operation cost than the manual protocol when considering marginal test costs, technical staff and specialist salary.Conclusion/DiscussionOur AI-based reflex protocol can successfully identify patients with pituitary dysfunction, with lower estimated laboratory cost. Future research will focus on enhancing the protocol’s accuracy and incorporating the AI-based reflex protocol into institutional laboratory and hospital information systems for the detection of undiagnosed pituitary disorders.     

Blood parasites: problems in diagnosis using automated differential instrumentation

To examine potential problems inherent in using automated differential instruments, we have reviewed herein two cases where blood parasites, Plasmodium vivax and Plasmodium falciparum, were completely missed by use of this method. Diagnosis of these infections was made when blood was sent to the parasitology laboratory after having been missed prior to that time. The first problem involved the laboratory request slip; no indication was made concerning possible suspect organisms. Therefore, peripheral blood examinations were performed using automated equipment. The number of fields scanned by a technologist on these smears is quite low; thus failure to pick up a light parasitemia is almost guaranteed. In both cases, after diagnosis had been made on smears submitted to the parasitology division, all previous smears examined by the automated system were reviewed and found to be positive for parasites. Failure to make the diagnosis resulted in delayed therapy. Although these instruments are not designed to detect intracellular blood parasites, the inability of the automated systems to discriminate between uninfected red blood cells and those infected with parasites may pose serious diagnostic problems.     

急性脑梗死患者血栓弹力图与常规凝血试验相关性分析

目的探讨血栓弹力图(TEG)各参数与常规凝血试验各指标间的相关性,评价2种方法在检测急性脑梗死患者凝血状况中的共性和差异性。方法选择107例急性脑梗死患者,所有患者住院期间均进行TEG检测,并同时与常规凝血试验做同步测定。结果显示急性脑梗死患者的反应时间(R值)和凝血酶形成时间(K值)较对照组明显缩短,血浆凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)检测指标偏低,且TEG检测的多项参数与常规凝血试验指标存在相关性。TEG参数中R值和K值与PT-国际标准化比率(PT-INR)呈正相关,与纤维蛋白原(FIB)水平呈负相关。α角和血栓最大弹力度(MA值)与PT-INR呈负相关,与FIB水平呈正相关。结论 TEG检测参数不仅能较全面地反映体内的凝血变化过程,而且与急性脑梗死患者的常规凝血试验指标间的水平存在相关性,与常规凝血试验同时检测,可起到互补作用。     

Correction of instrument- and reagent-based differences in determination of the International Normalized Ratio (INR) for monitoring anticoagulant therapy

As recommended by the World Health Organization, standardization of prothrombin time assays involves conversion of prothrombin times into International Normalized Ratios (INR). We investigated the effect of two different methods (Nycomed's Thrombotest, and Instrumentation Laboratory's PT-fibrinogen) and three coagulation instruments (Schnitger & Gross, KC-10, and ACL) on calculations of INR. The INR plots showed considerable scatter of individual values around the regression lines when the two different methods were compared. Systematic differences in the outcome of INR calculation were related to the use of the different coagulation instruments. Prothrombin times obtained with the different instruments were linearly correlated. We used the bias of these lines to correct results for both the patients' samples and the reference samples. This correction yielded INR values from the different instruments that agreed well.     

Tissue factor pathway inhibitor as a universal anticoagulant for use in clinical laboratory tests.

Tissue factor pathway inhibitor (TFPI) is a protease inhibitor of extrinsic coagulation. The present study investigates the possibility of utilizing TFPI as a universal anticoagulant in clinical laboratory tests. The optimal concentration of TFPI for use in clinical laboratory tests was found to be 1 microl TFPI/ml blood (100 mmol TFPI/ml blood); the subsequent analyses were conducted at this concentration. In hematological tests, complete blood cell count and differential white blood cell count were done with an automatic blood analyzer. The results except for platelet and white blood cell counts were similar for ethylenediaminetetraacetic acid (EDTA)-treated and TFPI-treated samples. The effects of TFPI on platelet count were more pronounced when blood samples were stored at 4 degrees C than at room temperature. The effects of TFPI on cell morphology were evaluated by spreading blood samples into thin films and applying a Giemsa stain. The results showed that TFPI did not alter the morphology of blood cells. An automatic biochemical analyzer performed seventeen basic biochemical tests on serum samples and TFPI-treated plasma samples. The results of seventeen tests were comparable between TFPI-treated samples and EDTA-treated samples. The prothrombin time for TFPI-treated plasma samples was longer than that for citrated plasma samples. Nonetheless, in activated partial thromboplastin time tests, the addition of the reagent caused turbidity and partial coagulation, thus demonstrating that TFPI is not suitable for this assay. These findings suggest that although some tests cannot be performed with TFPI, this compound may be useful as a universal anticoagulant in the future.     

Automated tests for the assessment of thyroid function.

Fully automated methods have been developed for the determination of thyroxine and triiodothyronine levels, antibodies to thyroglobulin and the assessment of thyroid hormone binding proteins in serum, using a continuous flow radioimmunoassay system. In addition the feasibility of a partially automated assay for thyrotrophin levels has been demonstrated. These employ Auto Analyzer modules and antibodies covalently linked to a magnetisable solid phase support. Separation of bound and free antigen is achieved by applying an external magnetic field. The system currently operates at a rate of 30 samples/h and requires only 10 minutes incubation since it is not necessary to reach equilibrium. The results are similar to those obtained by conventional manual techniques, however the precision is improved and operator error eliminated.     

Reference intervals for coagulation tests in adults with different ABO blood types

IntroductionCoagulation tests are affected by many factors, such as age, race, and gestation. Although coagulation test results vary by ABO blood type, reference intervals of different ABO blood groups remain to be determined. This study aims to investigate the reference ranges of coagulation tests for different ABO blood groups in the Han population in South China.MethodsA retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College. In all, 9600 individuals aged between 20 and 79 years were included. Coagulation tests, including prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), thrombin time, and fibrinogen, were performed.ResultsThere was a significant difference in PT, INR, and aPTT among ABO blood groups. PT and INR varied slightly between ABO blood groups. There was a higher aPTT value in individuals in the O blood group than in those in non‐O blood groups, in both males and females across the included age range. No differences were found in thrombin time and fibrinogen between the ABO blood groups.ConclusionThe study provides reference data on coagulation tests from ABO blood groups in South China. The established reference intervals specific to ABO blood type, sex, and age may improve clinical decisions based on coagulation tests.     

Massive blood transfusion in the elective surgical setting.

Massive haemorrhage in elective surgery can be either anticipated (e.g. organ transplantation) or unexpected. Management requires early recognition, securing haemostasis and maintenance of normovolaemia. Transfusion management involves the transfusion of packed red cells, platelet concentrates and plasma (fresh frozen plasma and cryoprecipitate). Blood product support should be based on clinical judgment and be guided by repeated laboratory tests of coagulation. Although coagulation tests may not provide a true representation of in vivo haemostasis, they do assist in management of haemostatic factors. Below critical levels (prothrombin time or activated partial thromboplastin time >1.8; fibrinogen <1.0 g/l; platelet count < 80 x 10(9) 1(-1)) it is difficult to achieve haemostasis. Despite seemingly adequate blood component therapy there remain situations where haemorrhage is uncontrollable. In this setting, alternative approaches must be considered. These include the use of other blood products (e.g. prothrombin complex concentrates; fresh whole blood; fibrin glue) and pharmacological agents (e.g. aprotinin). Complications of massive transfusion result in significant morbidity and mortality. These may be secondary to the storage lesion of the transfused blood products, disseminated intravascular coagulation, hypothermia or hypovolaemic shock. The use of fresh blood products and leucocyte-reduced packed red cells and platelets, may minimise some of the adverse clinical sequelae.     

Plasma transfusion for bedside, radiologically guided, and operating room invasive procedures

Frozen plasma (FP) is commonly used in an attempt to correct coagulation defects before performing bedside, radiologically guided, or operating room procedures. Use of FP prophylactically is closely linked to results for standard coagulation tests in the laboratory, including prothrombin time, but there is a general lack of evidence supporting the predictive value of abnormalities of these tests for bleeding. Use of FP has little effect on correcting abnormal coagulation tests when mild and moderate results are recorded. There is no support for evidence of effectiveness for the prophylactic use of FP when reviewing the wider randomized controlled trial literature. When the lack of clinical effectiveness is combined with the risks of FP transfusion, such as transfusion-related acute lung injury and transfusion-associated circulatory overload, the need to challenge continued preprocedure prophylactic use of FP becomes pressing. In clinical practice, abnormalities of standard coagulation tests should not be interpreted in isolation, but alongside review of clinical bleeding history and other hemostatic markers such as platelet count. A more appropriate transfusion strategy may be one that emphasizes the therapeutic use of FP.     

A Comparison of Autoanalyzer and Manual Methods for Red Cell Antibody Screening

A method for antibody screening using reagent red blood cells and the Technicon 15 Channel Blood Typing System is compared to the manual enzyme method of Löw. Of 17,473 donor units tested, 205 were found to be positive by the automated enzyme method, while only 45 were positive by the manual enzyme method. Further investigation revealed that 91 per cent of the specimens positive by the manual enzyme method showed specificity for red blood cell antigens, whereas only 40 per cent of those positive by the automated method were found to be specific antibodies. Antibodies specific for red blood cell antigens were detected by the automated method which were not detected by the manual enzyme method. However, all of these antibodies were detected in other phases (saline, albumin, or antiglobulin) of the routine manual antibody screening procedure. Thus, the use of the 15 Channel Blood Typing System to replace the manual enzyme method for antibody screening is not indicated because of the large number of false positive reactions which occur.     

Automated versus manual blood pressure measurement: a randomized crossover trial

This study evaluated the accuracy and reliability of the Dinamap 8100 automated blood pressure machine against three internationally recognized criteria. Systolic and diastolic blood pressures were taken concurrently by two nurses using the automated machine and a manual sphygmomanometer. Results demonstrated agreement between automated and manual readings on one set of criteria for both systolic and diastolic pressures, and support for systolic readings only on one other criterion. Comparison of mean differences between automated and manual measures showed the automated machine consistently under-read both systolic and diastolic blood pressures. The conclusion from this study was that the Dinamap 8100 machine can be used with some degree of confidence to assess systolic blood pressures in a general population of adult hospital inpatients, but with caution when taking diastolic readings.     

临产孕妇凝血及血细胞常规分析结果的意义

目的了解临产孕妇凝血常规4项指标及全血细胞发生生理性变化的状态，探讨其对分娩过程和产后发生凝血功能障碍的关联及影响。方法采用日本Sysmex CA-50自动血凝仪及迈瑞BC-3000plus自动血细胞分析仪对316例临产孕妇和130例健康非妊娠妇女进行凝血常规4项及全血细胞检测和分析。结果1）临产孕妇的凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）低于健康对照组（P〈0．05）；纤维蛋白原（Fbg）明显高于健康对照组（P〈0．01），凝血酶时间（TT）差异无统计学意义（P〉0．05）；2）临产孕妇的血红蛋白、红细胞计数及红细胞参数低于健康对照组（P〈0．01）；白细胞总数高于健康对照组，且以中性粒细胞为主（P〈0．01）；血小板计数低于健康对照组，平均血小板体积（MPV）及血小板分布宽度（PDW）高于健康对照组（P〈0．05）。结论临产孕妇血液处于高凝状态，动态监测凝血及血细胞指标，对预防和诊断分娩过程或产后发生的DIC及异常出血有重要意义。     

Significant increase of activated partial thromboplastin time by heparinization of the radial artery catheter flush solution with a closed arterial catheter system

OBJECTIVE: Evaluate whether the use of a heparinized flush for an arterial catheter with a closed-loop blood sampling system leads to erroneous coagulation studies. DESIGN: Prospective study. SETTING: Twenty-two-bed surgical adult intensive care unit in a university hospital. PATIENTS: Sixty patients, 30 in each phase of the study. INTERVENTIONS: Phase 1: coagulation studies on a blood sample from a venous puncture and an arterial blood sample from an arterial catheter with heparinized flush. Phase 2: the same protocol but the arterial catheter was flushed with saline. MEASUREMENTS: Activated partial thromboplastin time, fibrinogen, percentage of prothrombin time, and international normalized ratio of prothrombin time on the venous and arterial samples. MAIN RESULTS: Activated partial thromboplastin time in the arterial blood samples taken from an arterial catheter with heparinized flush was significantly prolonged compared with the venous controls. This was not the case in blood samples from an arterial catheter with saline flush. The magnitude of this difference found by the Bland and Altman analysis was clinically significant. In 23.3% of the patients in phase 1, there was a difference of >50% between the arterial and venous sampled activated partial thromboplastin time, compared with 0% of the patients in phase 2 (p =.018). There was no difference between the venous and the arterial blood samples for the non-heparin-sensitive coagulation studies in both phases of the study. An explanation for these findings could be that there was release of heparin bound to the arterial catheter into the blood sample. CONCLUSION: A heparinized flush solution for the arterial catheter, when used together with a closed-loop blood sampling system, leads to erroneous results of heparin-sensitive coagulation studies. Heparin-sensitive coagulation studies, therefore, should not be analyzed on blood samples from such a system if a heparinized flush solution is used.