scholarly journals Influence of dabigatran and rivaroxaban on routine coagulation assays

2015 ◽  
Vol 113 (01) ◽  
pp. 154-164 ◽  
Author(s):  
Els Bailleul ◽  
Bernard Chatelain ◽  
Anne Demulder ◽  
Katrien Devreese ◽  
Jonathan Douxfils ◽  
...  
Keyword(s):  
External Quality Assessment ◽  
Nationwide Survey ◽  
Activated Partial Thromboplastin Time ◽  
Dependent Manner ◽  
Activity Assay ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
Coagulation Assays ◽  
Coagulation Testing ◽  
Routine Coagulation

SummaryThe Belgian national External Quality Assessment Scheme performed a nationwide survey using lyophilised plasma samples spiked with dabigatran or rivaroxaban to demonstrate to the Belgian clinical laboratories how these drugs affect their routine coagulation assays prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and antithrombin. Virtually all Belgian laboratories performing routine coagulation testing (189/192) participated in the survey. Both, dabigatran and rivaroxaban significantly prolonged the PT and aPTT in a concentration- and reagent-dependent manner. PT reagents were more influenced by rivaroxaban than by dabigatran and aPTT reagents more influenced by dabigatran than by rivaroxaban. Among PT reagents, Neoplastin R® was the most sensitive to rivaroxaban and Innovin ® and Thromborel S® the least sensitive. Converting PT results to INR only increased the variability between reagents. Among aPTT reagents, Actin FSL® was the least sensitive to dabigatran while the other aPTT reagents showed slightly higher sensitivities. The presence of dabigatran led to falsely reduced fibrinogen concentrations when measured with a low thrombin concentration reagent. The presence of dabigatran caused an overestimation of the antithrombin level when measured with a thrombin-based activity assay and the presence of rivaroxaban an overestimation of the antithrombin level when measured with a FXa-based assay. Instrument-related differences were found for all tested parameters. In conclusion, this paper provides detailed information on the effect of dabigatran and rivaroxaban on routine coagulation assays as performed with a large number of reagent/instrument combinations.

Improvement of Coagulation Laboratory Practice in Thailand: The First-Year Experience of the National External Quality Assessment Scheme for Blood Coagulation

2009 ◽  
Vol 133 (1) ◽  
pp. 72-77
Author(s):  
Panutsaya Tientadakul ◽  
Nisarat Opartkiattikul ◽  
Wanida Wongtiraporn
Keyword(s):  
Quality Assessment ◽  
Blood Coagulation ◽  
Coefficient Of Variation ◽  
Partial Thromboplastin Time ◽  
External Quality Assessment ◽  
International Normalized Ratio ◽  
Activated Partial Thromboplastin Time ◽  
Laboratory Practice ◽  
External Quality ◽  
External Quality Assessment Scheme

Abstract Context.—In Thailand until 2005 there had been no external quality assessment scheme at the national level for blood coagulation tests. Only a few laboratories had an external quality assessment for these tests. In the year 2005, the Thailand National External Quality Assessment Scheme for Blood Coagulation was founded. Objectives.—To describe the establishment of the Thailand National External Quality Assessment Scheme for Blood Coagulation (including problems encountered and solutions), its progression and expansion, and the improvement of coagulation laboratory practice in Thailand during 2 trial surveys and 4 formal surveys conducted in the first 1;h1 years. Design.—Between 2005 and 2006, the external quality assessment samples for prothrombin time/international normalized ratio and activated partial thromboplastin time were distributed to the participants as well as the instructions and suggestions for the improvement of laboratory practice. From the data collected, the all-method coefficient of variation of the international normalized ratio and activated partial thromboplastin time was calculated for each survey. Results.—The number of participants increased during the first 1;h1 years that the surveys were conducted, from 109 to 127. Survey data demonstrate an improvement in response rate and an increase in the number of laboratories that determine their own reference ranges and repeat this for every change of reagent lot, using the appropriate anticoagulant. The increased precision of tests is indicated by the decrease of the all-method coefficient of variation of the international normalized ratio and activated partial thromboplastin time. Examples of individual laboratory improvement through feedback are also described. Conclusions.—The improvement of coagulation laboratory practice both through the instructions provided and liaison with participants was observed during the course of this scheme.

Interference of Blood Cell Lysis on Routine Coagulation Testing

2006 ◽  
Vol 130 (2) ◽  
pp. 181-184 ◽  
Author(s):  
Giuseppe Lippi ◽  
Martina Montagnana ◽  
Gian Luca Salvagno ◽  
Gian Cesare Guidi
Keyword(s):  
Blood Cell ◽  
Prothrombin Time ◽  
Partial Thromboplastin Time ◽  
Cell Lysis ◽  
Activated Partial Thromboplastin Time ◽  
Analytical Quality ◽  
Coagulation Assays ◽  
Coagulation Testing ◽  
Quality Specifications ◽  
Routine Coagulation

Abstract Context.—Preanalytical factors influencing the reliability of laboratory testing are commonplace. It is traditionally accepted that hemolytic samples are unsuitable for coagulation assays because of the release of hemoglobin, intracellular components, and thromboplastic substances from damaged blood cells. Objective.—To evaluate the influence of blood cell lysis on routine coagulation testing. Design.—Twelve aliquots prepared by serial dilutions of homologous lysated samples collected from 10 different subjects, and displaying a final percentage of lysis ranging from 0% to 9.1%, were tested for prothrombin time, activated partial thromboplastin time, fibrinogen, and dimerized plasmin fragment D. Lysis was achieved by subjecting citrated whole blood to a freeze-thaw cycle. Outcome Measures.—Interference from blood cell lysis on routine coagulation testing. Results.—Statistically significant increases in prothrombin time and dimerized plasmin fragment D were observed in samples containing final lysate concentrations of 0.5% and 2.7% respectively, whereas significant decreases were observed in activated partial thromboplastin time and fibrinogen in samples containing a final lysate concentration of 0.9%. The current analytical quality specifications for desirable bias are ±2.0% for prothrombin time, ±2.3% for activated partial thromboplastin time, and ±4.8% for fibrinogen. Percent variations from the baseline values exceeding the current analytical quality specifications for desirable bias were achieved for lysate concentrations of 0.9% (prothrombin time and activated partial thromboplastin time) and 1.8% (fibrinogen), corresponding to average free plasma hemoglobin concentrations of 1.7 and 3.4 g/L, respectively. Conclusion.—Our results confirm that, although slightly hemolyzed specimens might still be analyzable, a moderate blood cell lysis, as low as 0.9%, influences the reliability of routine coagulation testing. Because the interference in coagulation assays has a wide interindividual bias, we do not recommend lysis correction and we suggest that the most appropriate corrective measure should be free hemoglobin quantification and sample recollection.

Thromboplastin Related Differences in the Determination of International Normalised Ratio: A Cause for Concern?

1994 ◽  
Vol 72 (03) ◽  
pp. 426-429 ◽  
Author(s):  
S Kitchen ◽  
I D Walker ◽  
T A L Woods ◽  
F E Preston
Keyword(s):  
Patient Management ◽  
External Quality Assessment ◽  
Oral Anticoagulant Therapy ◽  
Warfarin Dosage ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
International Normalised Ratio ◽  
The Uk ◽  
The Relationship

SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.

Assessment of the correctness of identification and determination of antimicrobial susceptibility of Streptococcus pneumoniae in microbiological laboratories in Poland

2020 ◽  
Vol 55 (4) ◽  
pp. 271-276
Author(s):  
Ewa Młodzińska ◽  
Waleria Hryniewicz
Keyword(s):  
Quality Control ◽  
Antimicrobial Susceptibility ◽  
Bacterial Resistance ◽  
External Quality Assessment ◽  
Resistance Mechanisms ◽  
Medical Problems ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
Reliable Identification

The increase in bacterial resistance to antimicrobials is one of the most serious medical problems, therefore reliable identification in microbiological laboratories is important. The Polish National External Quality Assessment Scheme in Microbiological Diagnostics – POLMICRO programme is organized by the Centre of Quality Control in Microbiology (CQCM) enables the assessment of the competence of Polish microbiological laboratories in the field of identification, determination of susceptibility and detection of drug resistance mechanisms. This work presents the assessment of the results of identification and determination of S. pneumoniae antimicrobial susceptibility obtained by Polish laboratories during the 20 years of experience of the POLMICRO programme.

Establishing an Accuracy Basis for the Vitamin D External Quality Assessment Scheme (DEQAS)

2017 ◽  
Vol 100 (5) ◽  
pp. 1277-1287 ◽  
Author(s):  
Carolyn Q Burdette ◽  
Johanna E Camara ◽  
Federica Nalin ◽  
Jeanita Pritchett ◽  
Lane C Sander ◽  
...  
Keyword(s):  
Vitamin D ◽  
Quality Assessment ◽  
External Quality Assessment ◽  
Measurement Procedure ◽  
Binding Assays ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
Hydroxyvitamin D ◽  
Target Values ◽  
High Concentrations

Abstract Until recently, the Vitamin D External Quality Assessment Scheme (DEQAS) assessed the performance of various assays for the determination of serum total 25-hydroxyvitamin D [25(OH)D] by using a consensus mean based on the all-laboratory trimmed mean (ALTM) of the approximately 1000 participants' results. Since October 2012, the National Institute of Standardsand Technology (NIST), as part of the Vitamin D Standardization Program, has participated in DEQAS by analyzing the quarterly serum sample sets using an isotope dilution LC-tandem MS (ID LC-MS/MS) reference measurement procedure to assign an accuracy-based target value for serum total 25(OH)D. NIST has analyzed90 DEQAS samples (18 exercises × 5 samples/exercise) to assign target values. The NIST-assigned values are compared with the ALTM and the biases assessed for various assays used by the participants, e.g., LC-MS/MS, HPLC, and several ligand-binding assays. The NIST-value assignment process and the resultsof the analyses of the 90 DEQAS samples are summarized. The absolute mean bias between the NIST-assignedvalues and the ALTM was 5.6%, with 10% of the samples having biases &gt;10%. Benefits of the accuracy-based target values are presented, including for sample sets with high concentrations of 25(OH)D2 and 3-epi-25(OH)D3.

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