Measurement of INR at home. Apparatus, price

Today, the measurement of INR can be carry out independently at home. To do this, it is enough to purchase a special apparatus (called an INR analyzer or a coagulometer), the cost of which differs depending on the analyzer model and additional options. The device allows you to determine the parameters of blood clotting, on which the performance of organs depends. It should not be too thick or, conversely, liquid, since in either case we are talking about violations.

What is INR

INR is a laboratory indicator that determines the quality and intensity of blood clotting. Such an analysis must be carried out in the case of a patient taking certain medications, for example, warfarin, which can affect the process of blood clotting.

This indicator was first used in 1983. The analysis was included in standardized studies. The advantage of the method lies in the simplicity of testing. Today, it is possible to determine the level of clotting even at home.

The disadvantage of measuring is that if you use different equipment, then the results may differ. Therefore, experts advise using one device so that the results of a home study can be compared. This is due to the fact that the devices can use not only a different method of sample processing, but also differ in maximum error, the presence of a control system and many other parameters.

The measurement of INR at home is performed using an analyzer. It is a compact and lightweight device that you can use at home or take with you to work or on vacation. The compact device is equipped with a display that shows date, time and analysis results.

The data is stored in the device's memory (saving of the last 100-500 results is available), so it is not necessary to memorize or write them down in a separate notebook. Also, most modern analyzers can be connected to a PC.

The test is performed using a sterile needle that pierces the skin at the fingertip. Just one drop of blood is enough, which is placed on a special test strip. It remains to wait for the analyzer to display the result on the display. This usually takes no more than 1-2 minutes.

Even small children tolerate the procedure. In terms of the principle of operation and appearance, the INR analyzer is very similar to a glucometer, which is used to measure glucose levels. The main difference is that a deeper puncture is required to draw blood for glucose.

Sometimes it is necessary to measure blood clotting quite often. Thanks to the compact device, there is no need to visit a medical institution every time.

The analyzer will make life easier for those who suffer from:

• thrombosis;
• problems with blood clotting;
• atherosclerosis;
• gout;
• diabetes mellitus.

Why measure

Mostly, this type of test is done by doctors for patients who are taking warfarin. Thanks to the express test, you can eliminate the risk of bleeding or blood clots. If the INR index is increased, then this indicates excessive blood thinning. With reduced data, the risk of thrombosis increases.

For example:

• Below 4.5, the person experiences bleeding.
• If the analyzer gives less than 2, then the likelihood of a heart attack or other complications of the thromboembolic type increases.

Regular monitoring of blood clotting parameters is important for several reasons. First of all, when using warfarin, it is difficult to immediately determine the correct dosage, since even with minimal difference, there is a possibility that the drug will not have the proper effect or, conversely, cause complication. Another problem is that there is no specific dosage for the drug. Therefore, it is selected exclusively on an individual basis.

Sometimes, other drugs are prescribed to the patient in addition to warfarin. Thanks to the INR analysis, it is possible to determine if the effect of one substance is superimposed on another. But even with an accurate determination of the dosage, the effectiveness of the drug may decrease or increase from a variety of factors, for example, depending on the patient's diet and activity during day.

Types of devices

The measurement of INR at home is carried out using compact devices that cannot be fully called professional medical equipment.

The most accurate results can be obtained only if the tests are taken directly at a medical institution.

Laboratory

Laboratory units for measuring blood clotting are usually called coagulometers. These are dimensional devices that allow you to determine a variety of parameters of blood and plasma. The analysis is performed during the formation of a fibrin clot. Depending on the speed of this process, the equipment produces very accurate INR data.

Coagulometers are of optical and mechanical type. The difference between them is insignificant and lies more in the method for determining the indicators of a blood clot. Mechanical devices use a ball that mixes with the blood. In optical models, the measurement of the clot occurs during the determination of the optical properties of the test sample. This provides protection against the so-called external light. There are also combined models.

Portable

Compact analyzers are significantly smaller in size and are usually used as an intermediate research option when, for health reasons, a person cannot visit a doctor. Unlike laboratory equipment, such devices can be transported, which is very convenient.

Rating

Home measurement of INR should be performed using certified and reliable instruments. When choosing an analyzer, you should give preference to several popular models.

Coaguchek XS

One of the most popular models. The device is manufactured by the German company Roche Diagnostics. It is a leading global manufacturer of specialized equipment for medical institutions, as well as devices for performing self-diagnostics.

The cost of the device is approximately 39,000 rubles. Test strips will cost 7,400 rubles. for 24 pieces. Both capillary and venous blood can be used for the test. The device is considered the most accurate among analogs. The maximum error is no more than 3.5%. The device allows you to determine the INR values ​​within 0.8 - 8 units.

Among the disadvantages of the analyzer, one can single out a rather high price and the fact that such a device can be connected to a PC only with the help of a special connector, which must be purchased separately.

qLabs Electrometer

This is the main competitor to the previous model. The analyzer is manufactured by the Chinese company Micropoint Bioscience, which has specialized in diagnostic tools since 2006. The cost of the device is an order of magnitude lower and amounts to about 26,000 rubles.

Test strips will also cost less - up to 5,300 rubles. Only capillary blood can be used for testing. Also, this model is inferior to the German analogue in terms of error, which in this case is up to 5%. The measurement range is from 0.5 to 7.5 units.

The advantages of this model include the ability to connect to a computer using a USB cable, which is included in the kit. But Coaguchek XS is considered more stable in terms of the accuracy of the readings.

Coaguchek Pro II

This is another quality handheld analyzer from Roche Diagnostics. The time for checking blood clotting when using it is no more than a minute. The device has a fairly large display, which displays all the necessary information. In addition, the device provides numerous additional functions.

High accuracy of the result is achieved due to the system for checking the temperature of the test strips, the electronic systems of the device and other things. The kit for this model includes a power supply, so you don't have to buy anything.

Among the advantages of the device is extended memory, since the compact device is capable of storing up to 500 results. Accordingly, several people can use the device at the same time.

Capillary and venous blood can be used for analysis. Of the disadvantages of the device, one can single out the fact that in most stores the cost is hidden (available upon request). Judging by the characteristics of the device and the presence of a large screen, it costs an order of magnitude more expensive than the most popular Coaguchek XS model.

qLabs Electrometer Plus

This is another model from a Chinese manufacturer. From the name it is obvious that this device differs from the previous analyzer in more modern functions. But you will have to overpay for them, since such an analyzer will cost at least 53,000 rubles. The analysis itself takes a little longer - up to 2 minutes. The test requires very little capillary blood. INR is measured in the range from 0.85 to 1.2 units.

Electrometer Plus has a quality control system, calibration. The device meets international medical standards and has a maximum error of no more than 5%.

Coaguchek INRange

Measuring INR at home using this model is as simple and quite effective as possible. The advantages of the device include a convenient interface in Russian, a large display and flexible analyzer settings. For example, you can set the time when the instrument beeps loudly to remind you that it is time to test.

Unlike some analogs, this analyzer can be connected to a PC or smartphone via Bluetooth. Accordingly, it allows wireless transmission of test data. For this, a special application is provided that must be installed. However, a USB cable is included.

This is a new generation analyzer, so it is more convenient. The range of the measured INR values ​​is from 0.8 to 8 units, as in other models of analyzers from this manufacturer. Also, the device automatically performs calibration and multilevel quality control. Measurement is performed in less than 1 minute.

On the Internet, you can find other manufacturers of equipment. However, we are mainly talking about Chinese companies with a dubious history and reputation. Since we are talking about fairly accurate equipment, it is better to give preference to the manufacturers Roche Diagnostics and Micropoint Bioscience as the leading leaders in the portable healthcare market equipment.

Also, you should not buy devices that cost from 700 to 5,000 rubles, since devices of this type simply cannot be so cheap. cost, which means the research results will be completely inaccurate and even several thousand rubles will be spent wasted.

Home use

When doing home research, it is important to prepare responsibly. Blood tests can only be done on an empty stomach. This means that 7-8 hours before the analysis, you can not eat any food, as well as drink water, especially sweet water. But you shouldn't go hungry before research. If the patient does not eat for more than 10 hours before testing, then this can distort laboratory tests.

Do not engage in heavy physical activity a day before using the analyzer. This also applies to health-improving physical education.

For example, on the day of the analysis, you need to give up your morning run. This is due to the fact that during physical exertion (even insignificant), the oxygen saturation of the blood changes, as the speed of its flow also changes. You also need to give up various physiotherapy procedures, massage. Do not visit the sauna, beach. All this also distorts the test result.

If the patient is already taking any medications or even vitamins, it is imperative to discuss this with the doctor, as this may also change the test results. It is usually allowed to take the medicine no earlier than 17 hours before using the analyzer. The morning reception should be rescheduled for the time after the study.

The results of home diagnostics can be very distorted when taking oral contraceptives. You can use the INR device only 4 days after you stop taking such drugs.

The effect of warfarin is reduced if the patient takes:

• most types of antibiotics;
• drugs of the cardiac type, Amiodarone, Anaprilin;
• medicines belonging to the category of statins;
• pain relievers;
• antidepressants.

Norm and interpretation of INR

If we talk about standards, it is believed that the normal level of INR should be in the range of 0.85-1.15 units. When taking anticoagulants, the indicators increase. This means that fewer so-called coagulation factors are present in the blood. When taking such funds, the patient's norm is determined on an individual basis.

For example, when taking coagulants, the normal result is 2 to 3 units. Additionally, you need to take into account the patient's gender, weight, age and other factors. Also, the doctor must study in detail his anamnesis, medical history.

For example, based on age indicators, doctors distinguish the following norms:

Human age	Normal INR
Up to 1 year	0.9 to 1.25
1 to 6 years old	0.95 to 1.1
12-16 years old	Up to 1.35
Over 16 years old	t 0.85 to 1.3

An accurate interpretation of the analyzes can only be performed by a doctor, since for each patient the results can mean completely opposite things.

However, if you need to determine at least approximate data, then you can use the most frequent values ​​of the blood coagulation analysis:

• With an indicator from 0.85 to 1.15 units, we can say that this is the norm if the patient does not have any diseases that disrupt blood clotting. Also, this indicator indicates the normal course of coagulation processes.
• If the device shows from 2 to 3 units, then the INR is increased. Probably the patient is taking warfarin, which means he has certain pathologies, possibly atrial fibrillation. Also, such indicators are in people who are undergoing treatment for pulmonary embolism.
• If the display shows from 2.5 to 3.5 units, then this is considered normal only if the person has been installed a mechanical prosthesis of the atrial fibrillation.
• At 3.0-4.5 units, there is a suspicion that the patient has serious problems with the vascular bed or has a myocardial infarction.

However, no conclusions can be drawn from home research. It is better to take the device with you to the doctor and show him the check history or write the results on a piece of paper.

Selection recommendations

The measurement of INR at home can be performed using different models of analyzers.

When choosing such a device, you must pay attention to the following nuances:

• The number of indicators that the device determines. There are devices that allow you to simultaneously determine not only clotting, but also other blood parameters.
• Method of measurement. The most reliable is the electrochemical method.
• Availability of a certificate of conformity. It is important that devices of this type are accompanied by documents confirming the accuracy of the study.
• Analyzer performance. This is how many home tests the device can perform during the day. Based on the performance indicator, coagulometers are two-channel and four-channel. The former are suitable for 10-20 tests per day. Four-channel instruments can handle up to 40 samples. Some instruments are additionally equipped with the function of detecting the same results. They are marked accordingly.
• Sample volume. As a rule, modern instruments are able to determine the blood clotting index when 50 μL of sample and from 50 to 100 μL of reagents are loaded into the device. This is the optimal indicator. Smaller samples are only needed if the device is used for a baby or for screening. This savings also allows retests to be carried out.
• Information output system. The format of test results should be as convenient as possible. It is advisable to give preference to those models that can be connected to a portable printer and print test analyzes. However, they cost significantly more. Therefore, you can choose analyzers with additional connectors, through which you can connect the device to a PC and already from it print the results or send them to the attending physician by e-mail.
• Quality control. There are not so many analyzers of this type on the market and all of them use quality control software that meets only foreign standards. Therefore, it remains only to choose models in which there is at least control of duplicate definitions, which should be detected according to the coefficient of variation between 2 or 4 channels. Also, the device should provide for the control of the constructed calibration schedule.

Thus, the measurement of INR today is possible both in the laboratory and at home. In the second case, you need to purchase an analyzer and periodically buy special test strips. However, such devices are quite expensive and it is not yet so widely represented on the market, since patients prefer to visit a medical institution than pay about 26,000 - 50,000 rubles. for a home analyzer.

Video about devices for measuring INR

Measurement of INR using the qLabs device: