INR self-monitoring

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INR self-monitoring
Purposeself measure their INR (due to anti-coagulation therapy)

INR self-monitoring is a medical kit that is used by patients both on long-term and on lifetime anti-coagulation therapy to measure their INR (International Normalized Ratio) levels themselves at your premises without going to

Contents

a clinic. People who self-monitor their INR levels use a portable INR monitor as in a clinic. It requires the patient to test a drop of blood, drawn from a finger at scheduled times, and record the INR level measured by a monitor.

Patient self-testing

INR self monitoring with one blood drop. the INR is too high and the warfarine dose must be decreased. INR self test.jpg
INR self monitoring with one blood drop. the INR is too high and the warfarine dose must be decreased.

People on anti-coagulation therapy who are self-testing provide the INR reading they obtain from their monitor to their healthcare professionals at an agreed time, generally by telephone. The healthcare professional decides if any change to the warfarin dose is required and lets the person know what action is needed. A PT/INR meter can be obtained by contacting an Independent Diagnostic Testing Facility (IDTF). [1] They are able to provide patients with all necessary testing equipment and bill the insurance for test results reported.[ citation needed ]

Patient self-management

People who self-manage adjust their warfarin doses themselves, following training with their healthcare professional. This means that if the INR reading obtained from their monitor is out of the normal therapeutic range, they are able to make an adjustment to their own warfarin dose by themselves.[ citation needed ]

International Normalized Ratio (INR)

International normalized ratio (INR) which is a derivative of prothrombin time is a measurement of blood coagulation in the circulatory system. Both are used to determine the clotting rate of blood, which can be affected by anticoagulant usage, liver damage and Vitamin K levels. The preferred range of INR levels for a patient on anticoagulation therapy is usually between 2 and 3, but it tends to vary depending on the patient's requirements. [2]

The advantages of self-monitoring

Patients who self-monitor tend to choose this route for the greater control they feel it gives them over their lives and their condition. This helps to reduce the number of visits being made to their anticoagulation clinic for routine appointments to measure their INR levels. This is a lengthy process in comparison to self-testing and management. Results of clinical studies, which have been recognized by the National Patients Safety Authority (NPSA), show that people who self-monitor keep more frequently within their therapeutic range and have fewer complications including clots and bleeding, compared with people who have their INR levels tested only at their anticoagulation clinic.[ citation needed ]

UK NHS on self-monitoring

Patient self-care is a key initiative in the NHS Plan for a patient-centered health service and an important component in supporting people with long-term conditions. [3] It is seen to provide:

Who self-monitoring is suitable for

Self-monitoring may be a suitable option for a variety of people who are on long term anticoagulation therapy and want the convenience of being able to monitor their own INR levels at a time and place of their own choosing (e.g. if travelling abroad either with work or on vacation). They do have continuous support from their healthcare professionals and there are no upper age limits for self-monitoring and parents can take charge for their children. Self-monitoring is ideal if:[ citation needed ]

Clinical trials

In the past 5 years, there have been a number of clinical trials to highlight the advantages of self-monitoring, whether self-testing or self-managing. It also gives an indication of what improvements the self-testing and self-management can do to INR levels.[ citation needed ]

Clinical reports about INR self-monitoring

"Quality of life changed in a positive way. Independence and better organisation of vacation and spare time were most frequently mentioned advantages."

Extract from a study into the impact of self-monitoring on the quality of life of patients under anticoagulation therapy. [6]

"Patient self-testing . . . is an effective method of monitoring oral anticoagulation therapy, providing outcomes at least as good as, and possibly better than, those achieved with an anti-coagulation clinic."

From international consensus guidelines prepared by the International Self-Monitoring Association for Oral Anti-coagulation. [7]

"Self-monitoring can improve the quality of oral anti-coagulation therapy, with patients more frequently in the therapeutic range, while improving benefits and decreasing harm."

From the conclusions of a review of studies of self-monitoring in oral anti-coagulation therapy. [8] [9]

The results of the study Effect of Home Testing of International Normalized Ratio on Clinical Events (2010), comparing whether weekly home-testing of the INR-level offers any advantage over monthly testing in a clinic, reduces the risk of a major hemorrhage event (i.e. stroke, major bleeding, or death), indicated that the time to the first primary-event (stroke, major bleeding, or death) was not significantly longer in the self-testing group of patients than in the clinic-testing group of patients (hazard ratio, 0.88; 95% confidence interval, 0.75 to 1.04; p=0.14). The study was a prospective, randomized, non-blinded trial for which the patients were randomized into two groups, (i) weekly INR self-testing and (ii) monthly INR clinic-testing, using a stratified method of adaptive-allocation that was determined according to the duration of anti-coagulation and the indication for Warfarin. Although the study was non-blinded, blinding is less critical because the objective outcomes of the study: stroke, major bleeding episode, and death. [10]

Monitors

Patients who are self-monitoring have to use a monitor in order to measure their INR level. There are a range of INR testing monitors on the market, such as the CoaguChek XS, [11] [12] MicroINR., [13] INRatio2, [14] and QLabs [15]

See also

Related Research Articles

<span class="mw-page-title-main">Anticoagulant</span> Class of drugs

An anticoagulant, commonly known as a blood thinner, is a chemical substance that prevents or reduces the coagulation of blood, prolonging the clotting time. Some occur naturally in blood-eating animals, such as leeches and mosquitoes, which help keep the bite area unclotted long enough for the animal to obtain blood.

Liver function tests, also referred to as a hepatic panel, are groups of blood tests that provide information about the state of a patient's liver. These tests include prothrombin time (PT/INR), activated partial thromboplastin time (aPTT), albumin, bilirubin, and others. The liver transaminases aspartate transaminase and alanine transaminase are useful biomarkers of liver injury in a patient with some degree of intact liver function.

<span class="mw-page-title-main">Warfarin</span> Anticoagulant medication

Warfarin is an anticoagulant used as a medication under several brand names including Coumadin. While the drug is described as a "blood thinner", it does not reduce viscosity but rather inhibits coagulation. Accordingly, it is commonly used to prevent blood clots in the circulatory system such as deep vein thrombosis and pulmonary embolism, and to protect against stroke in people who have atrial fibrillation, valvular heart disease, or artificial heart valves. Less commonly, it is used following ST-segment elevation myocardial infarction (STEMI) and orthopedic surgery. It is usually taken by mouth, but may also be administered intravenously.

Low-molecular-weight heparin (LMWH) is a class of anticoagulant medications. They are used in the prevention of blood clots and, in the treatment of venous thromboembolism, and the treatment of myocardial infarction.

<span class="mw-page-title-main">Prothrombin time</span> Blood test that evaluates clotting

The prothrombin time (PT) – along with its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) – is an assay for evaluating the extrinsic pathway and common pathway of coagulation. This blood test is also called protime INR and PT/INR. They are used to determine the clotting tendency of blood, in such things as the measure of warfarin dosage, liver damage, and vitamin K status. PT measures the following coagulation factors: I (fibrinogen), II (prothrombin), V (proaccelerin), VII (proconvertin), and X.

<span class="mw-page-title-main">Bleeding diathesis</span> Medical condition

In medicine (hematology), bleeding diathesis is an unusual susceptibility to bleed (hemorrhage) mostly due to hypocoagulability, in turn caused by a coagulopathy. Therefore, this may result in the reduction of platelets being produced and leads to excessive bleeding. Several types of coagulopathy are distinguished, ranging from mild to lethal. Coagulopathy can be caused by thinning of the skin, such that the skin is weakened and is bruised easily and frequently without any trauma or injury to the body. Also, coagulopathy can be contributed by impaired wound healing or impaired clot formation.

<span class="mw-page-title-main">Ximelagatran</span> Anticoagulant

Ximelagatran is an anticoagulant that has been investigated extensively as a replacement for warfarin that would overcome the problematic dietary, drug interaction, and monitoring issues associated with warfarin therapy. In 2006, its manufacturer AstraZeneca announced that it would withdraw pending applications for marketing approval after reports of hepatotoxicity during trials, and discontinue its distribution in countries where the drug had been approved.

<span class="mw-page-title-main">Argatroban</span> Pharmaceutical drug

Argatroban is an anticoagulant that is a small molecule direct thrombin inhibitor. In 2000, argatroban was licensed by the Food and Drug Administration (FDA) for prophylaxis or treatment of thrombosis in patients with heparin-induced thrombocytopenia (HIT). In 2002, it was approved for use during percutaneous coronary interventions in patients who have HIT or are at risk for developing it. In 2012, it was approved by the MHRA in the UK for anticoagulation in patients with heparin-induced thrombocytopenia Type II (HIT) who require parenteral antithrombotic therapy.

<span class="mw-page-title-main">Warfarin necrosis</span> Medical condition

Warfarin-induced skin necrosis is a condition in which skin and subcutaneous tissue necrosis occurs due to acquired protein C deficiency following treatment with anti-vitamin K anticoagulants.

<span class="mw-page-title-main">Phenprocoumon</span> Drug

Phenprocoumon is a long-acting blood thinner drug to be taken by mouth, and a coumarin derivative. It acts as a vitamin K antagonist and inhibits blood clotting (coagulation) by blocking synthesis of coagulation factors II, VII, IX and X. It is used for the prophylaxis and treatment of thromboembolic disorders such as heart attacks and pulmonary (lung) embolism. The most common adverse effect is bleeding. The drug interacts with a large number of other medications, including aspirin and St John's Wort. It is the standard coumarin used in Germany, Austria, and other European countries.

<span class="mw-page-title-main">Dabigatran</span> Anticoagulant medication

Dabigatran, sold under the brand name Pradaxa among others, is an anticoagulant used to treat and prevent blood clots and to prevent stroke in people with atrial fibrillation. Specifically it is used to prevent blood clots following hip or knee replacement and in those with a history of prior clots. It is used as an alternative to warfarin and does not require monitoring by blood tests. In a meta analysis of 7 different studies, there was no benefit of dabigatran over warfarin in preventing ischemic stroke; however, dabigatran were associated with a lower hazard for intracranial bleeding compared with warfarin, but also had a higher risk of gastrointestinal bleeding relative to warfarin. It is taken by mouth.

Prothrombin complex concentrate (PCC), also known as factor IX complex, sold under the brand name Kcentra among others, is a combination medication made up of blood clotting factors II, IX, and X. Some versions also contain factor VII. It is used to treat and prevent bleeding in hemophilia B if pure factor IX is not available. It may also be used for reversal of warfarin therapy. It is given by slow injection into a vein.

Hypercoagulability in pregnancy is the propensity of pregnant women to develop thrombosis. Pregnancy itself is a factor of hypercoagulability, as a physiologically adaptive mechanism to prevent post partum bleeding. However, when combined with an additional underlying hypercoagulable states, the risk of thrombosis or embolism may become substantial.

The CHADS2 score and its updated version, the CHA2DS2-VASc score, are clinical prediction rules for estimating the risk of stroke in people with non-rheumatic atrial fibrillation (AF), a common and serious heart arrhythmia associated with thromboembolic stroke. Such a score is used to determine whether or not treatment is required with anticoagulation therapy or antiplatelet therapy, since AF can cause stasis of blood in the upper heart chambers, leading to the formation of a mural thrombus that can dislodge into the blood flow, reach the brain, cut off supply to the brain, and cause a stroke.

Venom-induced consumption coagulopathy (VICC) is a medical condition caused by the effects of some snake and caterpillar venoms on the blood. Important coagulation factors are activated by the specific serine proteases in the venom and as they become exhausted, coagulopathy develops. Symptoms are consistent with uncontrolled bleeding. Diagnosis is made using blood tests that assess clotting ability along with recent history of envenomation. Treatment generally involves pressure dressing, confirmatory blood testing, and antivenom administration.

Clotting time is a general term for the time required for a sample of blood to form a clot, or, in medical terms, coagulate. The term "clotting time" is often used when referring to tests such as the prothrombin time (PT), activated partial thromboplastin time, activated clotting time (ACT), thrombin time (TT), or Reptilase time. These tests are coagulation studies performed to assess the natural clotting ability of a sample of blood. In a clinical setting, healthcare providers will order one of these tests to evaluate a patient's blood for any abnormalities in the time it takes for their blood to clot. Each test involves adding a specific substance to the blood and measuring the time until the blood forms fibrin which is one of the first signs of clotted blood. Each test points to a different component of the clotting sequence which is made up of coagulation factors that help form clots. Abnormal results could be due to a number of reasons including, but, not limited to, deficiency in clotting factors, dysfunction of clotting factors, blood-thinning medications, medication side-effects, platelet deficiency, inherited bleeding or clotting disorders, liver disease, or advanced illness resulting in a medical emergency known as disseminated intravascular coagulation (DIC).

Direct factor Xa inhibitors (xabans) are anticoagulants, used to both treat and prevent blood clots in veins, and prevent stroke and embolism in people with atrial fibrillation (AF).

The management of atrial fibrillation (AF) is focused on preventing temporary circulatory instability, stroke and other ischemic events. Control of heart rate and rhythm are principally used to achieve the former, while anticoagulation may be employed to decrease the risk of stroke. Within the context of stroke, the discipline may be referred to as stroke prevention in atrial fibrillation (SPAF). In emergencies, when circulatory collapse is imminent due to uncontrolled rapid heart rate, immediate cardioversion may be indicated.

The SAMe-TT2R2 score is a clinical prediction rule to predict the quality of vitamin K antagonist anticoagulation therapy as measured by time in therapeutic INR range (TTR) (VKA e.g. warfarin). It has been suggested that it can aid in the medical decision making between VKAs and new oral anticoagulant/non-VKA oral anticoagulant (NOAC e.g. dabigatran, rivaroxaban, apixaban or edoxaban) in patients with atrial fibrillation (AF). This score can be used with patients with ≥1 additional stroke risk factors using the CHA2DS2-VASc score, where oral anticoagulation is recommended or should be considered.

Pump thrombosis (PT) is considered a specific case of a major device malfunction, and is classified as either suspected or confirmed pump thrombus. Typically, the device is an implanted blood pump such as a left ventricular assist device. The malfunction is a blockage in the flow of blood anywhere along a vessel and it is mainly due to the bio-incompatible presence of a fairly complex mechanical apparatus. Pump thrombus is dreaded complication of CF LVAD technology that can require repeat surgery to replace the pump or lead to death.

References

  1. ↑ "PT/INR Home Testing Service | How our Service Works". Archived from the original on 2014-03-03. Retrieved 2014-02-27.
  2. ↑ "International Normalized Ratio - Health Encyclopedia - University of Rochester Medical Center". www.urmc.rochester.edu. Retrieved 2022-10-27.
  3. ↑ "Self care - A real choice: Self care support - A practical option : Department of Health - Publications and statistics". www.dh.gov.uk. Archived from the original on 2007-03-23.
  4. ↑ Kulinna, W., Ney, D., Wenzel, T., Heene, D., & Harenberg, J. (1999). The Effect of Self-Monitoring the INR on Quality of Anticoagulation and Quality of Life. Seminars in Thrombosis and Hemostasis, 25(01), 123–126. doi:10.1055/s-2007-996435
  5. ↑ Gadisseur APA et al. Ann Intern Med 2004:2:584-91
  6. ↑ Kulinna, W., Ney, D., Wenzel, T., Heene, D., & Harenberg, J. (1999). The Effect of Self-Monitoring the INR on Quality of Anticoagulation and Quality of Life. Seminars in Thrombosis and Hemostasis, 25(01), 123–126. doi:10.1055/s-2007-996435
  7. ↑ Ansell J. et al. International Journal of Cardiology 2005:99:37-45
  8. ↑ Heneghan, Carl, et al. "Self-monitoring of oral anticoagulation: a systematic review and meta-analysis." The Lancet 367.9508 (2006): 404-411.
  9. ↑ http://onlinelibrary.wiley.com/o/cochrane/clsysrev/articles/CD003839/frame.html
  10. ↑ Matchar,D.B. (2010)"Effect of home testing of international normalized ratio on clinical events."
  11. ↑ "CoaguChek XS PT Test Strips".
  12. ↑ "Home | Discover INR self-testing with CoaguChek from Roche".
  13. ↑ "ILine microsystems". Archived from the original on 2019-04-17. Retrieved 2011-11-06.
  14. ↑ "Alere INRatio PT/INR Monitoring System - Home". www.alereinratio.pl. Archived from the original on 2011-02-21.
  15. ↑ "QLabs Q1 model 2019 PL – RedMed".
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