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1.
Int J Hematol ; 112(5): 614-620, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32929688

RESUMO

Accurate clotting time assay results are vital, as the test is employed to indicate the amount of oral anticoagulant to be prescribed, while it is also used for screening the hemorrhagic and thrombotic diseases. The procedure chosen for preparation of a patient blood sample including centrifugation can contribute to significant differences in the results obtained. Thus, for the purpose of proposing a standardized method to appropriately prepare blood samples prior to assay, the Japanese Society of Laboratory Hematology organized the Working Group for Standardization of Sample Preparation for Clotting Time Assays (WG). Following reviews of previously announced guidelines and original experimental results, consensus was obtained by the WG, with the main findings as follows. (1) The recommended anticoagulant in the blood collection tube is sodium citrate solution at 0.105-0.109 M (3.13-3.2%). (2) Whole blood samples should be stored at room temperature (18-25 ˚C) within 1 h of collection from the patient. (3) For plasma preparation, centrifugation at 1500 × g should be performed for at least 15 min or at 2000 × g for at least 10 min at room temperature. (4) After the plasma sample is prepared, it should be stored at room temperature and assayed within 4 h.


Assuntos
Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/normas , Coleta de Amostras Sanguíneas/métodos , Coleta de Amostras Sanguíneas/normas , Consenso , Manejo de Espécimes/métodos , Manejo de Espécimes/normas , Centrifugação , Humanos
2.
Ann Biol Clin (Paris) ; 78(5): 574-580, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32716002

RESUMO

Laboratories need to set up effective overall management of their internal quality control (IQC) and external quality assessment (EQA) results as key elements in statistical process control. Quality targets need to be defined, with methods to ensure durable control with respect to the relevant specifications. The hemostasis laboratory of the Lyon Hospitals Board (HCL, Lyon, France) uses model 3 from the Milan consensus conference, which is the state of the art in terms of quality targets, and uses a common EQA provider supplying as many real patient samples as possible. Giving priority to adopted methods, the lab optimizes the use of manufacturers' prior data: maximum acceptable inter assay coefficient of variation (CV) and prior IQC target values. Bayesian inference brings the method under control with respect to the manufacturers' prior data without the need for a preliminary phase. It links the IQC and EQA plans by the maximum acceptable CVs defined by the manufacturer.


Assuntos
Testes Hematológicos/estatística & dados numéricos , Testes Hematológicos/normas , Laboratórios Hospitalares/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Teorema de Bayes , Testes de Coagulação Sanguínea/instrumentação , Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/normas , Testes de Coagulação Sanguínea/estatística & dados numéricos , Serviços de Laboratório Clínico/organização & administração , Serviços de Laboratório Clínico/normas , Serviços de Laboratório Clínico/estatística & dados numéricos , França/epidemiologia , Testes Hematológicos/instrumentação , Testes Hematológicos/métodos , Hemostasia/fisiologia , Humanos , Laboratórios Hospitalares/organização & administração , Laboratórios Hospitalares/normas , Ensaio de Proficiência Laboratorial/organização & administração , Ensaio de Proficiência Laboratorial/normas , Ensaio de Proficiência Laboratorial/estatística & dados numéricos , Prática Profissional/organização & administração , Prática Profissional/normas , Prática Profissional/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde/métodos , Garantia da Qualidade dos Cuidados de Saúde/organização & administração , Garantia da Qualidade dos Cuidados de Saúde/normas , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Controle de Qualidade , Estudos Retrospectivos
3.
PLoS One ; 15(7): e0236528, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722691

RESUMO

BACKGROUND AND AIMS: Thromboelastometry (TEM) is superior to standard coagulation tests in the management of bleedings / invasive procedures in patients with liver cirrhosis. In contrast, the role of TEM as a prognostic parameter in liver cirrhosis is not well established. We therefore aimed to assess the role of TEM in predicting survival of outpatients with liver cirrhosis. METHODS: TEM was performed in consecutive outpatients with liver cirrhosis admitted in 2018 and 2019 to the University Hospital Essen. Associations with transplant-free survival were assessed in regression models. RESULTS: A number of 145 outpatients with liver cirrhosis were included, of whom 27 received a liver transplant (N = 7) or died (N = 20) within 6 months of follow-up. None of the TEM values was associated with transplant-free survival in this cohort. However, as expected, the classical coagulation tests INR (OR = 8.69 (95% CI 1.63-46.48), P = 0.01), PTT (OR = 1.15 (95% CI 1.04-1.27), P<0.01), as well as antithrombin (OR = 0.96 (95% CI 0.94-0.99), P<0.01), and protein C (OR = 0.96 (95% CI 0.92-0.99), P<0.01) were significantly associated with transplant-free survival. CONCLUSION: In contrast to the superiority of TEM over classical coagulation tests to guide transfusion of blood products in patients with liver cirrhosis, TEM has no relevance in predicting mortality in outpatients with liver cirrhosis.


Assuntos
Testes de Coagulação Sanguínea/normas , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico , Tromboelastografia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Padrões de Referência , Análise de Sobrevida , Adulto Jovem
4.
J Med Vasc ; 45(3): 125-129, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32402426

RESUMO

OBJECTIVE: The clinical relevance of hereditary thrombophilia (HT) testing in venous thromboembolic disease (VTE) is limited to specific guidelines. The present study aimed to evaluate the consistency of HT prescriptions in clinical practice according to the current French guidelines. METHODS: This study was conducted from April 2017 to February 2018 in a specialized haemostasis centre and included 58 consecutive patients referred by their clinicians for thrombophilia screening (56 patients following a personal VTE event and 2 asymptomatic relatives of a first-degree patient who had had VTE). One experienced clinician met every patient and assessed a pre-test prediction for the presence or absence of HT based on the clinical characteristics of VTE which was compared to the HT biological results. RESULTS: Among the 58 patients referred to our specialized haemostasis centre, 60% were outside the scope of recommendations for thrombophilia screening. Eight patients were diagnosed with HT. Six out of 8 (75%) patients with diagnosed HT had a history of unprovoked VTE event. Familial history with VTE was a poor predictor for positive HT testing among relatives. The positive and negative predictive values of the clinical prediction were respectively of 19% and 89%. CONCLUSION: The present results underline that screening for HT remains too largely prescribed. Pre-test physician's feeling for the presence of HT was neither sensitive nor specific. Increasing physicians' awareness on this issue and current recommendations should limit prescriptions of HT tests while providing the best possible care for patients with VTE.


Assuntos
Testes de Coagulação Sanguínea/normas , Coagulação Sanguínea , Fidelidade a Diretrizes/normas , Técnicas de Diagnóstico Molecular/normas , Guias de Prática Clínica como Assunto/normas , Encaminhamento e Consulta/normas , Trombofilia/diagnóstico , Tromboembolia Venosa/diagnóstico , Adolescente , Adulto , Idoso , Tomada de Decisão Clínica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Trombofilia/sangue , Trombofilia/genética , Tromboembolia Venosa/sangue , Tromboembolia Venosa/genética , Adulto Jovem
5.
Am J Emerg Med ; 38(6): 1226-1232, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32029342

RESUMO

BACKGROUND: Coagulation panels are ordered for a variety of conditions in the emergency department (ED). OBJECTIVE: This narrative review evaluates specific conditions for which a coagulation panel is commonly ordered but has limited utility in medical decision-making. DISCUSSION: Coagulation panels consist of partial thromboplastin time (PTT) or activated partial thromboplastin time (aPTT), prothrombin time (PT), and international normalized ratio (INR). These tests evaluate the coagulation pathway which leads to formation of a fibrin clot. The coagulation panel can monitor warfarin and heparin therapy, evaluate for vitamin K deficiency, evaluate for malnutrition or severe systemic disease, and assess hemostatic function in the setting of bleeding. The utility of coagulation testing in chest pain evaluation, routine perioperative assessment, prior to initiation of anticoagulation, and as screening for admitted patients is low, with little to no change in patient management based on results of these panels. Coagulation testing should be considered in systemically ill patients, those with a prior history of bleeding or family history of bleeding, patients on anticoagulation, or patients with active hemorrhage and signs of bleeding. Thromboelastography and rotational thromboelastometry offer more reliable measures of coagulation function. CONCLUSIONS: Little utility for coagulation assessment is present for the evaluation of chest pain, routine perioperative assessment, initiation of anticoagulation, and screening for admitted patients. However, coagulation panel assessment should be considered in patients with hemorrhage, patients on anticoagulation, and personal history or family history of bleeding.


Assuntos
Anticoagulantes/análise , Testes de Coagulação Sanguínea/normas , Medicina de Emergência/métodos , Anticoagulantes/uso terapêutico , Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/estatística & dados numéricos , Dor no Peito/sangue , Dor no Peito/diagnóstico , Serviço Hospitalar de Emergência/organização & administração , Heparina/análise , Heparina/uso terapêutico , Humanos , Coeficiente Internacional Normatizado/métodos , Coeficiente Internacional Normatizado/normas , Complicações Intraoperatórias/sangue , Complicações Intraoperatórias/diagnóstico , Tempo de Tromboplastina Parcial/métodos , Tempo de Tromboplastina Parcial/normas , Tempo de Protrombina/métodos , Tempo de Protrombina/normas , Varfarina/análise , Varfarina/uso terapêutico
6.
Blood Coagul Fibrinolysis ; 31(2): 145-151, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31977327

RESUMO

: Blood sampling via heparin-locked central venous catheter, including coagulation tests, is possible in accordance with the Clinical & Laboratory Standards Institute guidelines. However, differences exist between the test values of samples obtained from central venous catheter and those obtained from peripheral veins, even the guidelines are followed. To compare the coagulation time between blood samples from the heparin-locked central venous catheter and peripheral veins. In total, 72 hospitalized patients using heparin-locked Hickman catheters were enrolled. Blood samples for coagulation testing were simultaneously obtained via the peripheral veins and heparin-locked Hickman catheters. For sampling from the catheters, 0.9% sodium chloride flushing was performed and 10 or 23 ml of blood was discarded prior to collecting the coagulation test samples. Correlation, Bland-Altman plot, covariate, and regression analysis were performed for data analyses. Despite following the guidelines, the activated partial thromboplastin time test values differed. In the 10 ml of blood discard group, a correlation coefficient of 0.378 and a mean bias of 6.46 s were determined, while and in the 23 ml blood discard group, a correlation coefficient of 0.80 and a mean bias of 2.518 s were determined. Therefore, the volume of blood discarded from the heparin-locked Hickman catheters may affect the activated partial thromboplastin time test values.


Assuntos
Testes de Coagulação Sanguínea/normas , Cateteres Venosos Centrais , Flebotomia , Viés , Testes de Coagulação Sanguínea/métodos , Coleta de Amostras Sanguíneas , Correlação de Dados , Heparina , Humanos , Tempo de Tromboplastina Parcial
7.
Diagnosis (Berl) ; 7(1): 55-60, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31421038

RESUMO

Background Filling of citrate tubes with appropriate amount of blood is essential for obtaining reliable results of coagulation testing. This study aimed to verify whether results of routine coagulation tests are comparable when the new Becton Dickinson Vacutainer® Citrate Plus tubes are filled at minimum or optimal volume. Methods The study population consisted of 133 patients (40 on oral anticoagulant therapy), who had blood collected for routine coagulation testing. Two sequential Vacutainer® Citrate Plus tubes of the same type and lot were drawn. The first tube was collected after a butterfly needle was inserted into the vein, so that the air in the tubing was aspirated into the tube before blood (minimum fill volume), whilst the second was drawn at optimal fill volume. Experiments were repeated using 2.7-mL (n = 86) and 1.8-mL (n = 47) tubes. Results Prothrombin time (PT) and fibrinogen values were slightly but significantly decreased in tubes with minimum than in those with optimal fill volume. The activated partial thromboplastin time (APTT) was slightly prolonged in tubes with minimum than in those with optimal fill volume, but the difference was not statistically significant. An identical trend was noted in separate analyses for the 2.7-mL and 1.8-mL tubes. Spearman's correlations between the two fill volumes were always >0.94 and bias was always within the quality specifications. Conclusions Blood drawing into Vacutainer® Citrate Plus tubes at minimum fill volume does not clinically bias routine coagulation testing.


Assuntos
Anticoagulantes/farmacologia , Testes de Coagulação Sanguínea/instrumentação , Coleta de Amostras Sanguíneas/métodos , Ácido Cítrico/farmacologia , Flebotomia/instrumentação , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Testes de Coagulação Sanguínea/normas , Ácido Cítrico/administração & dosagem , Feminino , Fibrinogênio/análise , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Tromboplastina Parcial/instrumentação , Tempo de Tromboplastina Parcial/métodos , Tempo de Protrombina/instrumentação , Tempo de Protrombina/métodos
8.
Am J Hematol ; 95(1): 117-128, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31674066

RESUMO

Coagulation testing underpins the investigation of hemostasis and/or monitoring of anticoagulation therapy for prevention and/or treatment of thrombosis related pathology. Assessment of coagulation results requires comparison against a normal reference range or interval (NRR/NRI). Results flagged as "abnormal" (ie, above the NRR/NRI for patients not on anticoagulant therapy), typically require further evaluation. eg, follow up or reflexive testing is used to identify the reason for prolongation, especially when supported by clinical context (eg, bleeding). Mixing tests may have utility to help identify the pathway of follow-up testing (ie, towards investigation of factor deficiencies, or else inhibitors), and are also useful for investigation of lupus anticoagulants (LA). In general, mixing tests that "correct" tend to suggest the presence of factor deficiencies, where as those that do not correct suggest the presence of "inhibitors". Various approaches can be used to identify correction/non-correction, and all have strengths and limitations. Furthermore, eventual identification of causal factor deficiencies or even "inhibitors" may (eg, factor VIII or IX deficiencies or inhibitors) or may not (eg, factor XII deficiency) be clinically important. Ultimately, mixing studies performed in view of appropriate clinical scenarios (eg, bleeding patient) and for LA investigations in symptomatic patients will have best utility.


Assuntos
Testes de Coagulação Sanguínea/métodos , Inibidor de Coagulação do Lúpus/sangue , Algoritmos , Transtornos da Coagulação Sanguínea/diagnóstico , Testes de Coagulação Sanguínea/normas , Hemostasia , Humanos
9.
Clin Biochem ; 75: 78-82, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31770522

RESUMO

BACKGROUND: Till date, China has not issued industry standards for reference intervals (RIs) of pediatric blood coagulation indices. Here, we evaluated changes in the coagulation indices in the venous blood of healthy children aged 29 days to 12 years derived using the ACL Top 700 system and established appropriate RIs. METHODS: We analyzed venous blood from 1770 healthy children for five coagulation indices. RIs were established according to the Clinical and Laboratory Standards Institute C28-A3c guideline. RESULTS: The coagulation indices were grouped by age. For prothrombin time (PT) and international normalization ratio (INR), the RIs of infants and toddlers were identical; preschool children had the same RI as school-age children. Pediatric RIs for PT and INR were slightly lower than those for adults. The RIs of activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FIB) in childhood were divided into two groups by age (1 month to 1 year and 1-12 years). The RI of APTT in infants was the widest; the overall level of FIB in infants was the lowest; children's APTT and FIB RIs were lower than those of adults. The pattern of TT values and RI trends in childhood were similar to those of APTT. CONCLUSIONS: There were minor changes in the RIs of coagulation indices for children. The RIs of PT, INR, APTT, TT, and FIB must be grouped by age. The RIs of coagulation indices for children were different from those for adults; therefore, establishing separate RIs for children is necessary.


Assuntos
Testes de Coagulação Sanguínea/normas , Coagulação Sanguínea/fisiologia , Criança , Pré-Escolar , China/epidemiologia , Feminino , Voluntários Saudáveis , Humanos , Lactente , Recém-Nascido , Masculino , Valores de Referência
10.
Biochem Med (Zagreb) ; 30(1): 010702, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31839722

RESUMO

Introduction: Clinical application of rivaroxaban and apixaban does not require therapeutic monitoring. Commercial anti-activated factor X (anti-FXa) inhibition methods for all anti-FXa drugs are based on the same principle, so there are attempts to evaluate potential clinical application of heparin-calibrated anti-FXa assay as an alternative method for direct FXa inhibitors. We aimed to evaluate relationship between anti-FXa methods calibrated with low molecular weight heparin (LMWH) and with drug specific calibrators, and to determine whether commercial LMWH anti-FXa assay can be used to exclude the presence of clinically relevant concentrations of rivaroxaban and apixaban. Materials and methods: Low molecular weight heparin calibrated reagent (Siemens Healthineers, Marburg, Germany) was used for anti-FXa activity measurement. Innovance heparin (Siemens Healthineers, Marburg, Germany) calibrated with rivaroxaban and apixaban calibrators (Hyphen BioMed, Neuville-sur-Oise, France) was used for quantitative determination of FXa inhibitors. Results: Analysis showed good agreement between LMWH calibrated and rivaroxaban calibrated activity (κ = 0.76) and very good agreement with apixaban calibrated anti-Xa activity (κ = 0.82), respectively. Low molecular weight heparin anti-FXa activity cut-off values of 0.05 IU/mL and 0.1 IU/mL are suitable for excluding the presence of clinically relevant concentrations (< 30 ng/mL) of rivaroxaban and apixaban, respectively. Concentrations above 300 ng/mL exceeded upper measurement range for LMWH anti-FXa assay and cannot be determined by this method. Conclusion: Low molecular weight heparin anti-FXa assay can be used in emergency clinical conditions for ruling out the presence of clinically relevant concentrations of rivaroxaban and apixaban. However, use of LMWH anti-FXa assay is not appropriate for their quantitative determination as an interchangeable method.


Assuntos
Anticoagulantes/química , Testes de Coagulação Sanguínea/métodos , Heparina de Baixo Peso Molecular/química , Pirazóis/química , Piridonas/química , Rivaroxabana/química , Anticoagulantes/metabolismo , Área Sob a Curva , Testes de Coagulação Sanguínea/normas , Calibragem , Compostos Cromogênicos/química , Fator Xa/química , Fator Xa/metabolismo , Inibidores do Fator Xa/química , Inibidores do Fator Xa/metabolismo , Heparina de Baixo Peso Molecular/metabolismo , Humanos , Pirazóis/metabolismo , Piridonas/metabolismo , Curva ROC
12.
Spine Deform ; 7(6): 910-916, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31732001

RESUMO

STUDY DESIGN: Prospective, observational cohort study. OBJECTIVE: To improve the understanding of coagulation and bleeding mechanisms during spinal deformity surgery. SUMMARY OF BACKGROUND DATA: Fibrinolysis is the mechanism of bleeding for adolescent idiopathic scoliosis undergoing posterior spinal fusion. Antifibrinolytics have become popular; however, literature to support their use remains mixed. The mechanism of action has not been demonstrated. METHODS: The coagulation profile of 88 adolescent idiopathic scoliosis patients undergoing posterior spinal fusion was analyzed. Standard coagulation laboratory investigations and thromboelastograms were drawn hourly through the case. Fifty-eight patients received no antifibrinolytic, whereas 30 patients received tranexamic acid by standardized protocol. The coagulation parameters, estimated blood loss, and transfusion requirements were compared in the two groups. RESULTS: The two cohorts had no differences in demographic or surgical characteristics. Mean age was 13.6 years, 83% were female, a mean of 11.1 levels were fused, and the mean duration of surgery was 209 minutes. The tranexamic acid cohort did not demonstrate a decrease in blood loss. The transfusion rate, however, dropped from 47% in the non-tranexamic acid cohort to 23% in the tranexamic acid cohort (p = .03). Standard coagulation parameters did not differ between the groups. Fibrinolysis was diminished in the tranexamic acid cohort as measured by a Fibrinolysis score (mean maximum value 2.0 without tranexamic acid vs. 0.7 with tranexamic acid, p < .0001) and the lysis percent at 30 minutes by thromboelastogram (elevated to 3.9% without tranexamic acid vs. 1.2% with tranexamic acid at the 3-hour mark, p = .05). CONCLUSIONS: This study provides confirmation of antifibrinolytic activity during posterior spinal fusion for adolescent idiopathic scoliosis. The presented data of fibrinolysis are proposed as standard measurements for future work on controlling blood loss during scoliosis surgery. LEVEL OF EVIDENCE: Level 2, prospective comparative study.


Assuntos
Antifibrinolíticos/uso terapêutico , Escoliose/sangue , Escoliose/cirurgia , Fusão Vertebral/métodos , Ácido Tranexâmico/uso terapêutico , Adolescente , Antifibrinolíticos/administração & dosagem , Testes de Coagulação Sanguínea/normas , Perda Sanguínea Cirúrgica/prevenção & controle , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Transfusão de Sangue/estatística & dados numéricos , Criança , Feminino , Fibrinólise/efeitos dos fármacos , Humanos , Masculino , Duração da Cirurgia , Estudos Prospectivos , Escoliose/tratamento farmacológico , Fusão Vertebral/tendências , Tromboelastografia/estatística & dados numéricos , Ácido Tranexâmico/administração & dosagem
13.
Clin Appl Thromb Hemost ; 25: 1076029619876030, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31530176

RESUMO

Clinical uncertainty exists regarding which assay should be designated as the standard monitoring coagulation test for intravenous unfractionated heparin (UFH). Several studies have compared the use of activated partial thromboplastin time (aPTT) and antifactor-Xa (anti-Xa) and have come out with varying results. The correlation between these 2 tests varied, markedly from strong to weak. Some have demonstrated that monitoring with anti-Xa heparin assay leads to fewer dose adjustments, resulting in fewer laboratory tests, while others have not. In the current study, we evaluated the correlation between aPTT and anti-Xa values to guide clinical management of UFH, with the intention to develop a new correlation nomogram.


Assuntos
Testes de Coagulação Sanguínea/métodos , Heparina/uso terapêutico , Testes de Coagulação Sanguínea/normas , Inibidores do Fator Xa/análise , Feminino , Heparina/administração & dosagem , Humanos , Bombas de Infusão , Masculino , Pessoa de Meia-Idade , Tempo de Tromboplastina Parcial
14.
Int J Lab Hematol ; 41(6): 772-777, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31508901

RESUMO

INTRODUCTION: Lipemia in samples can cause analytical errors in coagulation tests using photometric assays. To define the level of this interference, some studies assessed lipemic interferences by in vitro 'spiking' of different types of lipids obtaining interesting information, but spiked samples do not represent a real-world situation as natively lipemic samples do. METHODS: A total of 101 samples flagged as 'lipemic' by a Sysmex CS-5100 coagulometer were analyzed for PT, aPTT, fibrinogen Clauss assay, antithrombin activity, D-dimer concentration, before and after a double high-speed centrifugation procedure to reduce lipemic interference. We evaluated using Bland-Altman test if high-speed centrifugation and retesting are justified, considering that's a resource-consuming procedure; when a statistically significant difference was found, quality specification for imprecision was considered and compared to the observed delta. RESULTS: Statistically significant differences were found for PT, antithrombin activity and fibrinogen. Considering the Bland-Altman plot, fibrinogen results were split into two groups, and statistically significant difference was confirmed only for samples >2 g/L. CONCLUSIONS: For PT and antithrombin activity a mean percentual difference between the two determinations lower than within-subject biologic variation and one of the Fraser's quality specifications can be considered as a confounding 'noise' factor that is neither analytically nor clinically relevant. If the instrument determines a result on the first run, for PT, aPTT, D-dimer concentration and antithrombin activity tests, the double plasma high-speed centrifugation is unnecessary. It is instead necessary if fibrinogen >2 g/L or if the instrument cannot determine a result on the first run.


Assuntos
Testes de Coagulação Sanguínea/instrumentação , Erros de Diagnóstico , Hiperlipidemias/sangue , Testes de Coagulação Sanguínea/normas , Centrifugação , Testes Diagnósticos de Rotina , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Fibrinogênio/análise , Tempo de Tromboplastina Parcial , Tempo de Protrombina
15.
Int J Lab Hematol ; 41(6): 731-737, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31487100

RESUMO

INTRODUCTION: The STA R Max® 2 is a new coagulation analyser developed by Diagnostica Stago, able to perform clotting, chromogenic and immuno-turbidimetric tests. A pre-analytical module build into the cap-piercing needle performs the sample integrity verification (sample tube filling and measurement of haemolysis, icterus, lipaemia). The STA R Max® 2 analyser incorporates an accreditation program tools to assist technical validation of the analyser. We assessed the analytical performance of the STA R Max® 2. MATERIALS AND METHODS: The following tests were assessed: prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, factor V (FV), antithrombin (AT), D-dimers (DDI) and von Willebrand factor antigen. The assay precisions were assessed using fresh plasma samples or internal quality controls. An inter-analyser comparison was performed with a STA-R Evolution® analyser or, for the FV, with a BCS® XP System. Haemolysis and icterus detection were also verified. RESULTS: For the intra-assay precision, the coefficients of variation (CV%) were all less than 5% and for DDI, the standard deviation (SD) was less than 0.1. For the inter-assay study, all CV% were less than 5%, with the exception of FV and AT (FV: 6.68% and 5.27%; AT: 7% and 12.14% for normal and pathological values, respectively). SD was less than 0.1 for DDI. The inter-analyser comparison demonstrated good results. Haemolysis and icterus were detected correctly for all our assessed samples. CONCLUSION: According to our methods validation's recommendations, the results demonstrated a good technical and analytical performance of the STA R Max® 2 analysers for the tests assessed.


Assuntos
Testes de Coagulação Sanguínea/instrumentação , Hemostasia , Testes de Coagulação Sanguínea/normas , Hemólise , Humanos , Icterícia/diagnóstico , Nefelometria e Turbidimetria , Controle de Qualidade , Reprodutibilidade dos Testes
16.
Int J Lab Hematol ; 41(6): 738-744, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31487115

RESUMO

INTRODUCTION: Direct oral factor Xa inhibitors (xabans) induce false positive results for lupus anticoagulant (LA) diagnosis. Consequently, it is suggested not to perform LA testing in xabans patients although it may be useful in selected patients. In this monocentric study, we evaluated xabans impact at trough levels (ie, just before the next intake) on LA diagnosis in treated patients using dilute Russell viper venom time (dRVVT) and two LA sensitive activated partial thromboplastin time (aPTT). METHODS: Sixty patients receiving rivaroxaban (30) or apixaban (30) were included. Plasma concentrations were measured using specific anti-Xa assays. LA testing was performed using one dRVVT (LAC-Screening® /Confirm® ; Siemens) and two LA sensitive aPTT-based assays (Hemosil® Silica Clotting Time (SCT) Screen/Confirm; Werfen and Dade® Actin® Factor Sensitivity FSL/FS (Actin F); Siemens). RESULTS: Median [min-max] concentrations were 23 [<18-68] for rivaroxaban and 42 ng/mL [19-99] for apixaban. dRVVT was positive in 93% of rivaroxaban and 40% of apixaban samples. SCT was positive in 40 and 30% and Actin F in 17 and 20% of samples respectively. Xabans affected more significantly dRVVT than aPTT-based assays (P < .001) with less false positive results with apixaban than with rivaroxaban samples irrespective of the assay used. CONCLUSION: lupus anticoagulant diagnosis in rivaroxaban and apixaban samples drawn at trough levels remains questionable whenever positive results are obtained. If LA testing in apixaban samples might be useful to rule-out LA using dRVVT and/or aPTT-based assays, the wide majority of rivaroxaban samples would give false positive results.


Assuntos
Inibidores do Fator Xa/administração & dosagem , Inibidor de Coagulação do Lúpus/sangue , Administração Oral , Síndrome Antifosfolipídica/sangue , Síndrome Antifosfolipídica/diagnóstico , Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/normas , Inibidores do Fator Xa/uso terapêutico , Reações Falso-Positivas , Humanos , Tempo de Tromboplastina Parcial , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Piridonas/farmacologia , Piridonas/uso terapêutico , Rivaroxabana/farmacologia , Rivaroxabana/uso terapêutico
17.
Clin Chim Acta ; 499: 108-114, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31513787

RESUMO

BACKGROUND: Appropriate reference intervals are essential when evaluating laboratory test results. However, establishment of reference intervals is challenging, especially for coagulation screening tests, and uncertainty exists regarding age- and sex-dependency of test results. Data mining of laboratory information systems is an emerging approach to reference interval determination, and we evaluated its applicability to coagulation tests. METHODS: We analyzed measurements of activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), thrombin time (TT), and fibrinogen performed during clinical care in the University Hospital Erlangen, Germany (1,778,738 samples from 116,754 adult patients, 45,577-509,859 samples per analyte). We identified the proportion of samples from healthy individuals using an established statistical approach (Reference Limit Estimator), in which the distribution of physiological test results is approximated using a parametrical function, and used for the calculation of reference intervals. RESULTS: We established age- and sex specific reference intervals for aPTT, PT, INR, TT, and fibrinogen, and created batch- and reagent-specific aPTT-reference intervals. Additionally, we evaluated the sensitivity of the established aPTT reference intervals for the detection of factor VIII, IX, XI, XII deficiencies. CONCLUSION: Data mining of laboratory test results allows the creation of age- and sex-reference intervals for coagulation tests that are specific to the examined population, analytical framework, and reagent. This approach can complement conventional methods when establishing reference intervals and improve clinical decision-making based on coagulation tests. The reference intervals established in this study show only minor variation with sex and age, supporting the practice of providing a common reference interval for adult women and men.


Assuntos
Testes de Coagulação Sanguínea/normas , Mineração de Dados , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Adulto Jovem
18.
Int J Lab Hematol ; 41(6): 745-753, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549775

RESUMO

INTRODUCTION: The currently recommended preanalytical conditions for lupus anticoagulant (LA) analysis require analyzing samples in fresh or freshly frozen platelet-poor plasma. The aim of this study was to evaluate whether alternative and less cumbersome preanalytical procedures for LA testing give significantly different results compared to recommended conditions. MATERIALS AND METHODS: Citrated blood samples were drawn from 29 study participants, 15 with negative and 14 with positive LA results. The samples were processed according to the ISTH guideline for LA testing and compared to several alternative preanalytical conditions. Measurements were performed using the dilute Russell's viper venom time (DRVVT) and silica clotting time (SCT), both screen and confirm, on a STA-R Evolution analyzer. Stability criteria were based upon biological variation. RESULTS: All DRVVT tests (normalized screen, confirm, and screen/confirm ratio) met the stability criteria for all the preanalytical conditions. The SCT tests (normalized screen, confirm, and screen/confirm ratio) met the stability criteria only when treated according to the ISTH guideline, except for SCT normalized screen/confirm ratio which also met the stability criteria for double-centrifuged aliquoted plasma stored in room temperature for 24 hours and then analyzed "fresh" or after being frozen. One warfarin-treated patient was reclassified from positive to negative for DRVVT after the preanalytical modifications, while 2 of 29 participants became falsely positive for 2 of 8 conditions for SCT. CONCLUSIONS: The DRVVT assays met the criteria for stability for all preanalytical conditions tested, while the SCT assays should be interpreted with caution if the preanalytical guidelines from ISTH are not followed.


Assuntos
Testes de Coagulação Sanguínea/métodos , Inibidor de Coagulação do Lúpus/sangue , Síndrome Antifosfolipídica/sangue , Síndrome Antifosfolipídica/diagnóstico , Testes de Coagulação Sanguínea/normas , Coleta de Amostras Sanguíneas , Células Cultivadas , Centrifugação , Reações Falso-Positivas , Humanos
19.
BMC Med Inform Decis Mak ; 19(1): 123, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31269951

RESUMO

BACKGROUND: The autoverification system for coagulation consists of a series of rules that allow normal data to be released without manual verification. With new advances in medical informatics, the laboratory information system (LIS) has growing potential for the autoverification, allowing rapid and accurate verification of clinical laboratory tests. The purpose of the study is to develop and evaluate a LIS-based autoverification system for validation and efficiency. METHODS: Autoverification decision rules, including quality control, analytical error flag, critical value, limited range check, delta check and logical check, as well as patient's historical information, were integrated into the LIS. Autoverification limited range was constructed based on 5 and 95% percentiles. The four most commonly used coagulation assays, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FBG), were followed by the autoverification protocols. The validation was assessed by the autoverification passing rate, the true-positive cases, the true-negative cases, the false-positive cases, the false-negative cases, the sensitivity and the specificity; the efficiency was evaluated in the turnaround time (TAT). RESULTS: A total of 157,079 historical test results of coagulation profiles from January 2016 to December 2016 were collected to determine the distribution intervals. The autoverification passing rate was 77.11% (29,165/37,821) based on historical patient data. In the initial test of the autoverification version in June 2017, the overall autoverification passing rate for the whole sample was 78.75% (11,257/14,295), with 892 true-positive cases, 11,257 true-negative cases, 2146 false-positive cases, no false-negative cases, sensitivity of 100% and specificity of 83.99%. After formal implementation of the autoverification system for 6 months, 83,699 samples were assessed. The average overall autoverification passing rate for the whole sample was 78.86% and the 95% confidence interval (CI) of the passing rate was [78.25, 79.59%]. TAT was reduced from 126 min to 101 min, which was statistically significant (P < 0.001, Mann-Whitney U test). CONCLUSIONS: The autoverification system for coagulation assays based on LIS can halt the samples with abnormal values for manual verification, guarantee medical safety, minimize the requirements for manual work, shorten TAT and raise working efficiency.


Assuntos
Testes de Coagulação Sanguínea , Sistemas de Informação em Laboratório Clínico , Técnicas de Laboratório Clínico , Aplicações da Informática Médica , Segurança , Testes de Coagulação Sanguínea/normas , Sistemas de Informação em Laboratório Clínico/normas , Técnicas de Laboratório Clínico/normas , Humanos , Segurança/normas , Design de Software
20.
Int J Lab Hematol ; 41(5): 642-649, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31271498

RESUMO

INTRODUCTION: Haemostasis laboratories play a critical role in diagnosis and treatment of individuals with bleeding or thrombotic disorders. Routine coagulation assays such as prothrombin time (PT)/ international normalized ratio (INR), and activated partial thromboplastin time (APTT), are used in monitoring of anticoagulant therapy, as provided for treatment/prevention of thromboembolic disease, and also inform on potential haemostasis dysfunction. Increasing pressure is applied on clinical laboratories to improve response (test turnaround) times, reduce error rates and standardize policies. To this end, we describe our experience with the development and implementation of an automated process for reflex testing and validation of routine coagulation test results in a large pathology network compromising 27 laboratories. METHODS: Custom-built expert rules were created to perform reflex testing and fully automate routine test validation. These rules were developed/implemented over a 15-month period, including 6 months for development/ testing and 9 months for training/implementation of >100 personnel at 27 sites. RESULTS: These rules have enabled adherence of standardized pre-analytical (sample integrity) checks, automated reflex decisions, automated verification and overall alignment of network practices. In addition, clinically significant results are immediately referred to haematologists. We report an improvement in test turnaround times, also reflecting savings in operator time. CONCLUSION: The process was generally well received and generally beneficial to most laboratories in the network.


Assuntos
Anticoagulantes/farmacologia , Automação Laboratorial/normas , Testes de Coagulação Sanguínea/normas , Coagulação Sanguínea/efeitos dos fármacos , Testes Diagnósticos de Rotina/normas , Automação Laboratorial/métodos , Testes de Coagulação Sanguínea/métodos , Testes Diagnósticos de Rotina/métodos , Hemostasia/efeitos dos fármacos , Humanos , Coeficiente Internacional Normatizado , New South Wales , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Padrões de Referência , Reflexo , Reprodutibilidade dos Testes
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