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.

Point-of-care monitoring of vitamin K-antagonists: validation of CoaguChek XS test strips with International Standard thromboplastin

2012 ◽  
Vol 65 (11) ◽  
pp. 1031-1035 ◽  
Author(s):  
Anton M H P van den Besselaar ◽  
Nathalie C V Péquériaux ◽  
Marij Ebben ◽  
Joke van der Feest ◽  
Kerst de Jong ◽  
...  
Keyword(s):  
The Netherlands ◽  
Vitamin K ◽  
Point Of Care ◽  
Vitamin K Antagonists ◽  
Capillary Blood ◽  
Blood Samples ◽  
Test Strips ◽  
International Standard ◽  
The Mean ◽  
Coaguchek Xs

AimsMany patients treated with vitamin K-antagonists (VKA) use point-of-care (POC) whole blood coagulometers for self-testing. The majority of patients in the Netherlands use one type of POC coagulometer, that is, the CoaguChek XS. Each new lot of test strips for the CoaguChek XS is validated by a group of collaborating thrombosis centres. We assessed the International Normalised Ratio (INR) differences between each of 51 new lots of test strips and the International Standard for thromboplastin rTF/95 or its successor rTF/09.MethodsEach year, a particular lot of CoaguChek XS test strips was used as reference lot. The reference lot was validated by comparison to the International Standard, yielding a relationship between the reference lot INR and International Standard INR. Successive lots of test strips were compared to the reference lot by three centres using 19–29 capillary blood samples obtained from VKA-treated patients. Each patient provided two blood drops from the same finger prick, one for the reference lot strip and one for the new lot.ResultsThe mean INR differences between each lot and the International Standard varied between −8% and +4%. The mean absolute values of the relative differences varied between 2.4% and 8.1%. There were small but clinically unimportant differences in INR between the first and second drop of blood.ConclusionsAccuracy of CoaguChek XS INR determinations can be assessed by a group of collaborating centres using a limited number of capillary blood samples. As the mean INR differences with the International Standard were smaller than 10%, the lots were approved for use by the Netherlands Thrombosis Services.

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.

Circulating Osteocalcin During Oral Anticoagulant Therapy

1988 ◽  
Vol 60 (01) ◽  
pp. 079-082 ◽  
Author(s):  
L J M van Haarlem ◽  
M H J Knapen ◽  
K Hamulyák ◽  
C Vermeer
Keyword(s):  
Vitamin K ◽  
Oral Anticoagulant ◽  
Human Subjects ◽  
Oral Anticoagulant Therapy ◽  
Vitamin K Antagonists ◽  
Serum Levels ◽  
Coagulation System ◽  
Oral Anticoagulant Treatment ◽  
Steady State Levels ◽  
Osteocalcin Production

SummaryIn this paper we present the following observations:1) In sheep vitamin K-antagonists like phenprocoumon induce a decrease of the serum levels of osteocalcin (bone Gla-protein) and of the affinity of the circulating osteocalcin for hydroxyapatite.2) In sheep vitamin K counteracts the effect of phen-procoumon on the blood coagulation system, but not that on the osteocalcin production.3) In human subjects vitamin K-antagonists also lead to decreased levels of serum osteocalcin and a low affinity of the protein for hydroxyapatite.4) These two variables reached steady-state levels within 24 h after the start of oral anticoagulant treatment and - at continu-ation of the therapy - they remained low for at least several years.

Comparative study of i-SENS glucometers in neonates using capillary blood samples

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ha Nui Kim ◽  
Soo-Young Yoon
Keyword(s):  
Reference Values ◽  
Point Of Care ◽  
Evaluation Process ◽  
Capillary Blood ◽  
Performance Criteria ◽  
Accuracy Evaluation ◽  
Blood Samples ◽  
Average Reference ◽  
Error Grid ◽  
Accuracy Performance

Abstract Objectives The accuracy of point-of-care blood glucometers in the detection and evaluation of neonatal hypoglycemia is a concern. This study compared the performance of three i-SENS glucometers with that of the YSI 2300 STAT Plus Analyzer, which was used as a reference. Methods The leftover neonatal capillary blood samples of 319 patients were used in this study. The evaluation process and accuracy performance criteria were based on the International Organization for Standardization 15197:2013 guidelines. The evaluation involved three i-SENS glucometers (BAROzen H Expert plus, CareSens PRO, and CareSens H Beat) and the ACCU-CHEK® Inform II glucometer. Results The accuracy evaluation yielded acceptable results as follows: a) 100 and 100% for BAROzen H Expert plus; 99.8 and 100% for CareSens PRO; 98.7%, and 97.2% for CareSens H Beat glucometers were within the range of ±0.8 mmol/L (15 mg/dL) and ±15% of the average reference values at glucose concentrations <5.55 mmol/L (100 mg/dL) and ≥5.55 mmol/L (100 mg/dL), respectively, and b) all estimated glucose values (100%) were within the zones A and B of Consensus Error Grid for all three i-SENS glucometers. There was good correlation between the glucose values estimated by the glucometers and the reference values (R>0.990). Conclusions This study demonstrated that i-SENS glucometers exhibit acceptable performance and can be used as effective point-of-care devices in neonates.

scholarly journals HAS-BLED scor system for the assessment of risk of breathing of patients on oral anticoagulant therapy // HAS-BLED skor sistem bodovanja za procjenu rizika od krvarenja pacijenata na oralnoj antikoagulantnoj terapiji

2018 ◽  
Vol 5 (1) ◽  
pp. 11
Author(s):  
Daniela Dobrovoljski
Keyword(s):  
Atrial Fibrillation ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Heart Rhythm ◽  
Clinical Problem ◽  
Coagulation Factors ◽  
Heart Rhythm Disorders ◽  
Anticoagulant Drugs

Oral anticoagulant drugs (OALs) are effective agents in the prevention and treatment of thromboembolic complications. However, despite standardization and application progression, OALs represent a significant clinical problem because they are small-therapeutic medicines that easily interact with food and medicine, which can substantially affect the increased or weakened therapeutic effect. Oral anticoagulants are 4-hydroxycoumarin derivatives and vitamin K antagonists, and their pharmacological activity is based on inhibition of the synthesis of coagulation factors in the liver. These drugs are effective in the prevention of venous thromboembolism, acute myocardial infarction (AIM), heart rhythm disorders by type of atrial fibrillation, stroke prevention, and the like. The most important and clinically commonly undesirable effect of OAL is bleeding. The risk of bleeding is greatest during the introduction of the drug in therapy and for the first few months of the onset of therapy. HAS-BLED scor is a skoring system developed to estimate the 1-year risk of major bleeding in patients with atrial fibrillation and is also used for other indications.

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.

Rebound Phenomenon After Discontinuation Of Oral Anticoagulant Therapy?

1981 ◽  
Author(s):  
J Harenberg ◽  
R Haas ◽  
R Zimmermann
Keyword(s):  
Anticoagulant Therapy ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
In Vitro Release ◽  
Oral Anticoagulant Treatment ◽  
Thrombin Activity ◽  
Rebound Phenomenon

Duration and discontinuation of oral anticoagulant therapy in the prophylaxis of recurrent thrombembolic diseases is often discussed. After stopping of the therapy an elevated incidence of rethromboses are observed. Therefore we determined fibrinopeptide A (FPA) as the most sensitive parameter of thrombin activity in vivo in patients treated with phenprocoumon in order to get information on the effectivity of the oral anticoagulant therapy and on the rebound phenomenon after discontinuation of the treatment.In 136 outpatients a significant relation between FPA and the effectivity of the anticoagulant therapy was observed: 2.7 ng/ml plasma (mean, thrombotest values < 5%), 3.5 ng/ml (5%-15%) and 4.1 ng/ml (>15%, p < 0.01). Normal FPA were 1.4ng/ml. In 11 patients with low FPA the oral anticoagulants were discontinued. FPA was determined in weekly intervalls. Within four weeks a continous increase of FPA from 1.6 ng/ml (median) to 3.8 ng/ml was observed. After eight weeks FPA was 8.2 ng/ ml (p < 0.05). The in vitro release of FPA after 10 min incubation of blood increased from 3.4ng/ml to 72 ng/ml after eight weeks (p < 0.05, normal release up to 5 ng/ml).The data indicate the clinical relevance and the different therapeutic implications of the determination of FPA in patients treated with phenprocoumon. They further give the first criterion, which outlines the effectivity of an oral anticoagulation therapy by reducing the thrombin activity in vivo. They give some evidence for a rebound like phenomenon after discontinuation of the oral anticoagulant treatment.

Suspension of Vitamin K Antagonists Is Not Required for Cataract Surgery: A Prospective Study in a Cohort of 135 Consecutive Patients on Long-Term Anticoagulant Therapy.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 882-882
Author(s):  
Berardino Pollio ◽  
Giuseppe A. Demarie ◽  
Patrizia Ocello ◽  
Grazia Delios ◽  
Marco Tucciarone ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Anticoagulant Therapy ◽  
Vitamin K ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Vitamin K Antagonists ◽  
Management Service ◽  
Corneal Incision ◽  
Standardized Protocol

Abstract The perioperative management of oral anticoagulant therapy (OAT) often arouses controversy between surgeons and internists. In geriatric patients, cataract surgery for those who are taking vitamin K antagonists is a common clinical procedure. Phacoemulsification requires a 3 mm incision involving a tissue devoid of blood vessels. This study reports the experience of an Italian Anticoagulation Management Service (AMS) with 135 anticoagulated patients on long-term anticoagulant therapy who underwent phacoemulsification performed by the same ophthalmologist team from January 2001 to December 2005. The patients received either topical (30%) or peribulbar (70%) anaesthesia. Data were collected by physicians with specialized software, but the dosage of oral anticoagulant was manual. Two oral vitamin K antagonisists are available in Italy: acenocumarol and warfarin. We prepared all patients in accordance with the following standardized protocol : the scheduled dose was always omitted the day before surgery an INR measurement was provided 3–5 days before the invasive procedure; if the patient’s INR was below 3, we simply omitted the scheduled dose of the day before cataract surgery if the patient’s INR was above 3, we withheld two or more scheduled doses to allow the INR to fall to 2.5 or less 1 hour before cataract surgery, INR was measured if the patient’s INR was below 2.5, phacoemulsification was performed Results: This standardized procedural protocol allowed the surgeon to carry out phacoemulsification with INR always below 2.5. We observed only one peribulbar bleeding (0.7%) during peribulbar anaesthesia before the corneal incision was made. No thromboembolic complications were registered during three months of follow up. We compared our results with the data of an earlier cohort of 7014 conventional patients who underwent this eye surgery in the same ophthalmologic institute. We did not observe statistical differences between the two groups with regard to hemorragic complications. Conclusions: The risk of thromboembolism when antithrombotic therapy is interrupted is a well-grounded concern, particularly for patients with mechanical heart valves. Low molecular weight heparin bridging is a valid but more complicated alternative. Our study demonstrates the feasibility and safety of this simple standardized protocol which avoids OAT interruption. Therefore, we conclude that in patients receiving OAT, it is not necessary for the anticoagulant effect to wear off before cataract surgery is performed.

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