The Use of Evacuated Tubes for Blood Collection in Oral Anticoagulant Control

1983 ◽  
Vol 50 (03) ◽  
pp. 676-677 ◽  
Author(s):  
A M H P van den Besselaar ◽  
L P van Halem-Visser ◽  
E A Loeliger
Keyword(s):  
Prothrombin Time ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Blood Collection ◽  
Anticoagulant Treatment ◽  
Contact Activation ◽  
Oral Anticoagulant Treatment ◽  
Blood Samples ◽  
Evacuated Tubes

SummaryThe prothrombin time (PT) test is used to monitor oral anticoagulant therapy. Contact activation of patient blood samples in vitro may shorten the PT and thus lead to underestimation of the degree of anticoagulation. Commercial evacuated tubes for blood collection have been reported to induce shortening of the PT. The Thrombotest modification of the PT determination was used to investigate the properties of different brands of evacuated siliconized tubes. Two recently manufactured batches of such tubes did not induce appreciable shortening of the PT and can therefore be recommended for use in monitoring oral anticoagulant treatment.

scholarly journals Régi és új orális antikoagulánsok hazai alkalmazása pitvarfibrillációban

2017 ◽  
Vol 158 (39) ◽  
pp. 1545-1549
Author(s):  
János Tomcsányi ◽  
Balázs Salfer ◽  
Bence Nagy
Keyword(s):  
Atrial Fibrillation ◽  
Vitamin K ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Real Life ◽  
Vitamin K Antagonist ◽  
Anticoagulant Treatment ◽  
Oral Anticoagulant Treatment ◽  
New Oral Anticoagulant ◽  
Method Analysis

Abstract: Introduction: Despite a progress in the management of patients with atrial fibrillation this arrhythmia is one of the major causes of stroke, heart failure, sudden death and cardiovascular morbidity. Oral anticoagulation with vitamin K antagonist or non-vitamin K antagonist markedly reduces stroke and mortality in atrial fibrillation patients. Aim: To estimate the real-life vitamin K antagonist and non-vitamin K antagonist oral anticoagulant treatment in past years in Hungary. Method: Analysis of the National Health Insurance Administation database for atrial fibrillation (BNO: I48) between 2010–2015. We assumed that AF patient would turn to health care provides at least once either as inpatients or outpatients in a 5-year period. The patient was accepted as adherent after 6 months therapy and at least 80% oral anticoagulant prescription. Results: The prevalence of AF in Hungary is 3%. The mortality rate of AF 7%–10% per year. The adherence of the old oral anticoagulant treatment was 55%, but it was 69% among patient treated by “new” oral anticoagulant treatment. However, one third of the patients are not treated by effective old or new oral anticoagulant treatment. Conclusions: We need more effort to improve the effective and high adherence oral anticoagulant therapy in our country. Orv Hetil. 2017; 158(39): 1545–1549.

The association between atrial fibrillation and pulmonary embolism

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Svennberg ◽  
L Friberg
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Embolism ◽  
Risk Factor ◽  
Anticoagulant Therapy ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Funding Source ◽  
Anticoagulant Treatment ◽  
Oral Anticoagulant Treatment ◽  
Increased Risk

Abstract Background and objectives Previous studies have suggested that atrial fibrillation is a risk factor for pulmonary embolism. Oral anticoagulant therapy is the mainstay of treatment for atrial fibrillation and pulmonary embolism. We wanted to investigate if atrial fibrillation remained associated with the development of pulmonary embolism if oral anticoagulant treatment was accounted for. Method In this retrospective registry study a random sample of 20% of the adult Swedish population comprising approximately 1.5 million individuals were included during 2010–2017 in a cohort analysis. The endpoint was acute pulmonary embolism. In the cohort study, patients were analysed according to oral anticoagulant treatment and presence of atrial fibrillation at baseline. Results The group with atrial fibrillation was >25 years older than the group without and had almost three times higher incidence of pulmonary embolism (2.91 vs 1.09 /1000 year at risk, p<0.001). Individuals with atrial fibrillation on oral anticoagulant therapy had a lower risk of pulmonary embolism in multi-variable analysis (HR 0.59, CI 0.45–0.77). In the unadjusted analysis participants with atrial fibrillation without oral anticoagulant therapy showed an increased risk of pulmonary embolism (HR 3.33, CI 3.05–3.63). However, after multi-variable adjustment this association disappeared (HR 0.98, CI 0.89–1.07). In the entire atrial fibrillation cohort, no association was seen with the development of pulmonary embolism after multi-variable adjustment (HR 0.92, CI 0.84–1.01). The higher rate of pulmonary embolism among patients with atrial fibrillation can be fully explained by differences in age and co-morbidity. Conclusion Atrial fibrillation does not appear to be a clinically relevant risk factor for pulmonary embolism. Oral anticoagulant therapy protects against the development of pulmonary embolism in patients with atrial fibrillation. Associations with pulmonary embolism Funding Acknowledgement Type of funding source: Other. Main funding source(s): The main author has received funding from Stockholm County Council (Clinical postdoctorial appointment)

Unreliability of Point of Care Devices for INR Monitoring of Oral Anticoagulant Therapy. A Re-Evaluation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2206-2206
Author(s):  
Caryn O. Sands ◽  
Vilma Padilla ◽  
Khrishan Naraine ◽  
Jacob Rand ◽  
Amy S. Fox
Keyword(s):  
Oral Anticoagulant ◽  
Dose Adjustment ◽  
Point Of Care ◽  
Oral Anticoagulant Therapy ◽  
Vitamin K Antagonists ◽  
Rapid Analysis ◽  
Capillary Blood ◽  
Ease Of Use ◽  
Oral Anticoagulant Treatment ◽  
Blood Samples

Abstract Oral anticoagulant treatment with vitamin K antagonists has been encumbered by the need for interval monitoring of INRs to adjust dosage. Point of Care (POC) testing of capillary blood has come into widespread use because of the advantages of rapid analysis and dose adjustment. To assess the reliability of this procedure, we compared INR results from 2 POC devices from different manufacturers - POC1 and POC2 - and compared these results to standard assays on venous samples with a BCS automated analyzer. 78 patients on warfarin for at least 3 months were studied. Results of 56 patients with POC2 and 76 patients with POC1 were compared to the BCS. Capillary blood samples were taken within 30 minutes of the venous draw. The therapeutic INR range was considered to be 2.0–3.5. The bias plots for the 2 POC methods compared to the reference INR are shown in the 2 Figs, below. Within the therapeutic range, 71% and 85% of the results correlated with BCS for POC1 and the POC2, respectively. Both instruments showed the greatest variation from the reference measurement at INR values greater than 2.5 Both POC methods demonstrated clinically relevant overestimates of INR(see table). Figure Figure Figure Figure Agreement % of Reference INR Values to POC INR Reference INR* POC1-subtherapeutic POC1-therapeutic POC1-supratherapeutic POC2-subtherapeutic POC2-therapeutic * INR = 2.0–3.5 BCS-subtherapeutic 77% 23% - 63% 37% BCS-therapeutic 4% 71% 25% 5% 85% BCS-supratherapeutic - - 100% - 33% Conclusion: This study raises a significant question rearding the accuracy of POC methods for INR determinations. Despite ease of use and immediacy of results, the lack of correlation, even under study conditions, and the potentials for under-and overdosing makes relying on these devices problematic.

A Multicenter Study on Amidolytic Factor X Evaluation in Oral Anticoagulant Therapy

1985 ◽  
Vol 53 (03) ◽  
pp. 433-436 ◽  
Author(s):  
A M Berthier ◽  
M Pommereuil ◽  
P Y Scarabin ◽  
J Conard
Keyword(s):  
Prothrombin Time ◽  
Multicenter Study ◽  
Oral Anticoagulant ◽  
Large Scale ◽  
Oral Anticoagulant Therapy ◽  
Strong Positive Correlation ◽  
Chromogenic Substrate ◽  
Factor X ◽  
Oral Anticoagulant Treatment ◽  
Automated Instruments

SummaryFor laboratory control of oral anticoagulation, amidolytic factor X (F X) determination may offer an alternative to standardization difficulties of prothrombin time (PT). In order to validate this amidolytic assay on a large scale, a multicenter study was undertaken in 6 French laboratories using the same chromogenic substrate (Stachrom X Stago) and different automated instruments. Intra and between laboratory reproducibility of factor X was estimated on fresh and lyophilized patients plasmas and was found to be highly satisfactory. Standardization of the method did not seem to depend on the chromogenic substrate used, as investigated in two different centers. Results of PT and factor X were compared in over 500 patients on a longterm stabilized oral anticoagulant treatment: there was a strong positive correlation between the 2 tests in each center. The therapeutic range for factor X was evaluated from therapeutic PT values reported by Duckert and Marbet for the different thromboplastin reagents: the estimated mean range was 21 to 32%.Pooling the results of the six different centers a concordant information for prothrombin time and factor X amidolytic assay was found in 76% of patients and a fully discordant response was present in 0.6%. The results suggest that amidolytic factor X may be suitable for monitoring long-term anticoagulation. However, prospective trials are needed to evaluate its usefulness as compared to conventional methods.

PROTHROMBIN TIME MONITORING OF ORAL ANTICOAGULANT TREATMENT: COMPARISON OF INSTRUMENTS AND THROMBOPLASTINS

1987 ◽  
Author(s):  
M P Seveso ◽  
A Macagni ◽  
S Viganò D'Angelo ◽  
C Manotti ◽  
P A Bonini ◽  
...  
Keyword(s):  
Liver Disease ◽  
Prothrombin Time ◽  
Oral Anticoagulation ◽  
Oral Anticoagulant ◽  
Plasma Sample ◽  
Laboratory Monitoring ◽  
Anticoagulant Treatment ◽  
Oral Anticoagulant Treatment ◽  
Treatment Comparison ◽  
Excessive Anticoagulation

The prothrombin time (PT) is the most widely used assay to monitor oral anticoagulation (OA). Although it has been established that both thromboplastin and instrumentation significantly affect the results, major standardization attempts have been devoted to the calibration of reagents rather than of instruments. To provide safe laboratory monitoring of OA, an International Sen sitivity Index (ISI) for thromboplastin has been introduced. We have compared two automatic coagulometers, the ACL (Instrumentation Laboratory), a laser-nephelometer centrifugal analyzer which measures the intensity of the light scattered by a plasma sample before, during and after clot formation and the KOAGULAB 40A (Ortho Diagnostics), an optical automatic coagulometer, with the till tube technique for the performance ofPT. Five calibrated commercial thromboplastins have been used for replicate determinations in 30 normals, 30 liver disease patients and 30 patients on stabilized OA. The overall observed imprecision (C.V.) was 1.1% for ACL, 2.9% for the KOAGULAB 40A and 3.0% for the till tube technique. The F test for the two-way interaction of ratios was statistically significant (p< O.OOl) for the large majority of reagent/technique combinations in normals and in liver disease patients. Internatio nal normalized ratios were also significantly different (p< O.OOl) in most instances in patients on OA. Inadequate anticoagulation (INR<2.0)was observed in 18% of patients with the ACL , in 31% with the KOAGULAB 40A and in 33% with the till tube technique. Excessive anticoagulation (INR> 4.5) was observed in 19% of the patients with the ACL, in 7% with KOAGULAB 40A and in 3% with the till tube tech nique. These data highlight the need for standardization of both instrumentations and reagents to improve monitoring of OA.

scholarly journals Preanalytical Variables and Off-Site Blood Collection: Influences on the Results of the Prothrombin Time/International Normalized Ratio Test and Implications for Monitoring of Oral Anticoagulant Therapy

2005 ◽  
Vol 51 (3) ◽  
pp. 561-568 ◽  
Author(s):  
Johanna HH van Geest-Daalderop ◽  
André B Mulder ◽  
Leandra JM Boonman-de Winter ◽  
Martha MCL Hoekstra ◽  
Anton MHP van den Besselaar
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Oral Anticoagulant ◽  
Room Temperature ◽  
Oral Anticoagulant Therapy ◽  
International Normalized Ratio ◽  
Blood Collection ◽  
Ratio Test ◽  
Mechanical Agitation ◽  
The Impact

Abstract Background: The quality of oral anticoagulant therapy management with coumarin derivatives requires reliable results for the prothrombin time/International Normalized Ratio (PT/INR). We assessed the effect on PT/INR of preanalytical variables, including ones related to off-site blood collection and transportation to a laboratory. Methods: Four laboratories with different combinations of blood collection systems, thromboplastin reagents, and coagulation meters participated. The simulated preanalytical variables included time between blood collection and PT/INR determinations on samples stored at room temperature, at 4–6 °C, and at 37 °C; mechanical agitation at room temperature, at 4–6 °C, and at 37 °C; time between centrifugation and PT/INR determination; and times and temperatures of centrifugation. For variables that affected results, the effect of the variable was classified as moderate when &lt;25% of samples showed a change &gt;10% or as large if &gt;25% of samples showed such a change. Results: During the first 6 h after blood collection, INR changed by &gt;10% in &lt;25% of samples (moderate effect) when blood samples were stored at room temperature, 4–6 °C, or 37 °C with or without mechanical agitation and independent of the time of centrifugation after blood collection. With one combination of materials and preanalytical conditions, a 24-h delay at room temperature or 4–6 °C had a large effect, i.e., changes &gt;10% in &gt;25% of samples. In all laboratories, a 24-h delay at 37 °C or with mechanical agitation had a large effect. We observed no clinically or statistically relevant INR differences among studied centrifugation conditions (centrifugation temperature, 20 °C or no temperature control; centrifugation time, 5 or 10 min). Conclusions: We recommend a maximum of 6 h between blood collection and PT/INR determination. The impact of a 24-h delay should be investigated for each combination of materials and conditions.

A Comparison of Two Sodium Citrate Concentrations in Two Evacuated Blood Collection Systems for Prothrombin Time and ISI Determination

2000 ◽  
Vol 84 (10) ◽  
pp. 664-667 ◽  
Author(s):  
V. Chantarangkul ◽  
A. Tripodi ◽  
A. M. H. P. van den Besselaar
Keyword(s):  
Prothrombin Time ◽  
Sodium Citrate ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Practical Importance ◽  
Blood Collection ◽  
Blood Samples ◽  
Polyethylene Terephtalate ◽  
Glass Tubes ◽  
The Difference

SummaryThe prothrombin time is usually measured in citrated plasma. The W.H.O. recommended concentration of sodium citrate for blood collection for laboratory control of oral anticoagulant therapy is 0.109 M. Some evacuated blood collection systems include 0.105 M sodium citrate. The purpose of the present study was to establish the difference in ISI calibration between 0.109 and 0.105 M citrate, using 7 types of thromboplastin and various types of instrumentation. The two citrate concentrations were provided in both evacuated siliconised glass tubes and in evacuated polyethylene terephtalate (PET) tubes. The ISI difference between the two citrate concentrations was 5.4% for one system but not greater than 3% for all other systems when blood samples were collected with either siliconized glass or PET tubes. Most of the ISI differences between the two citrate concentrations were not significant at the 5% level. It is concluded that the ISI differences between 0.105 M and 0.109 M citrate are not of practical importance. In contrast, ISI differences between siliconised glass and PET tubes, using either 0.105 or 0.109 M citrate, were significant (p <0.05) for most thromboplastin systems and amounted to 7%. ISI interchange between these glass and PET tubes could induce INR differences amounting to 14%, which could affect clinical dosage of oral anticoagulants.

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