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Coagulometer (hemostasis analyzer) is a device that is used to study the level of blood coagulation. Semi-automatic and automatic medical device provides the most accurate and reproducible research results. The device allows you to determine indicators that other types of analyzes cannot reveal.
How does a coagulometer work?
The medical device is designed to study hemostasis, with its help four tests are determined: fibrinogen test (the time of formation of a fibrin clot in a biomaterial taken from a patient is analyzed); thrombin test (you need to know the indicator in case of a violation of blood clotting, treatment with heparin); APTT test (important for determining coagulation disorders, monitoring during heparin therapy); prothrombin test (helps to monitor the effectiveness of anticoagulant treatment).
In modern medicine, coagulometers have replaced visual analysis, which a few decades ago was carried out using a stopwatch and a bath. Manual diagnosis is not XNUMX% accurate and there is a risk of misdiagnosis. It also increases the risk of hemorrhagic bleeding or thrombus formation.
New models of coagulometers make it possible to obtain accurate information, since they are based on optical-mechanical and mechanical detection methods. Devices are automatic and semi-automatic. Automatic equipment is the best option for use in medical institutions that receive a large number of patients daily. With the help of automatic hemostasis analyzers, diagnostics can be carried out in a short period of time. Plus, these devices have more power (performance), compared to a semi-automatic.
Semi-automatic devices are needed for diagnostics using the clotting technique: fibrin or a whole blood clot is formed. To conduct a study using a semi-automatic coagulometer, you will need only 50 to 200 µl. In small and medium laboratories, mobile diagnostic centers, semi-automatic coagulometers are installed.
Fields of application of the device
Hemostasis analyzers are used for diagnostics in various fields, in particular, in medicine. In hematology, the device is used to detect pathological changes related to hemostasis and disorders of the anticoagulant system. In cardiology, a coagulometer is needed to examine the patient’s blood clotting during the treatment of heart disease.
In hepatology, the device helps in the treatment of hepatitis and cirrhosis of the liver. The hemostasis analyzer is necessary to adjust the therapy of people who take anticoagulants. In surgery, the equipment is used to control the use of “Warfarin” and transfusion treatment.
In maternity hospitals, a coagulometer is one of the most important devices, since with its help a doctor can control the level of hemostasis in women who are carrying a child and women in labor. The device is used to conduct a rapid test showing violations of hemostasis.
When is a hemostasis test needed?
An analysis of blood clotting, which is carried out using a coagulometer, is necessary before surgery, as well as to determine pathological changes in the body. The study allows you to assess the likelihood of hemorrhages and blood clots during surgery.
Indications for analysis are:
- disruption of the liver;
- injuries that are accompanied by external and internal bleeding;
- miscarriage;
- ischemia of the heart, pre-infarction state and infarction;
- tendency to form blood clots, thrombosis;
- long-term treatment with certain drugs.
With hemorrhagic pathological changes, chronic anemia, bleeding from the nasal cavity, heavy periods, neoplasms in urine and feces, it is necessary to do an analysis for blood clotting.
During a routine medical examination, the doctor can often send patients for this analysis.
Preparing and performing a hemostasis test
You should prepare for the diagnosis in advance: before the manipulation, you can not eat and drink at least 10-12 hours before. 2-3 days before donating blood, it is not recommended to eat fatty, spicy and canned food. You can only drink pure water. Tea, coffee, juice, compote, alcoholic drinks are also prohibited.
Half an hour before the manipulation, you can not be nervous, worry, physically load yourself and smoke. If the patient has used anticoagulant drugs a few days ago, the attending physician should be warned about this. Important is the dosage and duration of the course of therapy. If, during the sampling of the biomaterial, a person begins to feel sick, dizzy, and his health worsens, you should immediately tell the medical worker about these manifestations.
Analysis using a coagulometer is quite simple: to obtain reliable results, a nurse or nurse takes venous or capillary blood. The volume of the biomaterial ranges from 25 µl to 200 µl. The standard volume of blood for the study is 50 µl. The resulting sample is placed in the apparatus and after a short period of time the results are displayed on the monitor (4 main indicators and additional ones). The resulting information is compared with generally accepted standards.
Norms of hemostasis
Evaluation of the results of the study should be carried out according to the standards of a particular diagnostic center or laboratory. A prothrombin time of 11-15 seconds is considered normal. The INR indicator should vary from 0,82 to 1,18 measuring units. The prothrombin index is normally 72-123%. Thrombin time should be within 14-21 seconds, 76-126% is the norm for antithrombin.
The norm of fibrinogen is 2,7-4 grams. Within the range of 0,36-0,48 measuring units, fibrin-monomer complexes dissolve, and the D-diameter indicator should be from 250 to 550 ng / ml.
What do high and low numbers indicate?
The indicator of the rate of blood clotting allows not only to assess the speed of fibrin formation, but also the time between the onset and end of bleeding. When examining a bioassay taken from a vein, the rate of thrombus formation should be within 5-10 minutes.
If the indicator is higher than normal, this indicates a possible hemophilia, vitamin C deficiency, pathological changes in the liver, thrombocytopenia. An increase in hemolysis may occur due to treatment with medications such as Aspirin, Warfarin, and Trental.
If the blood coagulates in 3-4 minutes, this indicates an accelerated formation of clots or extensive bleeding. Deviation from the norm in the direction of decrease often occurs in women due to the use of contraceptive drugs.
Other parameters during the study show the occurrence of a number of diseases and disorders in the body. For example, a deviation from the norm of the APTT indicator may indicate autoimmune diseases, liver pathology, DIC.
How to choose a coagulometer for a medical institution
When choosing a device, you need to take into account the number of parameters that it determines. New models of hemostasis analyzers perform more than 16 tests. There are three methods for diagnosing and registering a clot: the first is optical-mechanical (optical and mechanical methods); the second is optical; the third is mechanical. Doctors consider the first technique to be the most effective.
In order for the coagulometer to work properly, you need to know about its power. By performance, the devices are:
- single-channel (do up to ten samples per day);
- two-channel (from 10 to 20 samples per day);
- four-channel (up to forty tests per day).
The World Health Organization recommends that medical institutions purchase coagulometers with two and four channels to avoid errors during the study.
Hemostasis analyzers work with small volumes of biomaterial, so the devices are used in screening and pediatrics. A small amount of spent bioassays allows you to test if necessary from 1 to 3 times. The data received by the instrument can be printed out using a printer.
When buying a coagulometer for a laboratory, you should pay attention to the number of channels, the number of compartments for biomaterial and reagents. In modern devices, it is possible to transfer information to a laboratory information network (LIN).
Advantages of the coagulometer
The advantages of the hemostasis analyzer include: one hundred percent reliability of the results of the analysis; the minimum amount of consumable biological materials; minimum cost of medicines; convenient display of results; the ability to print the received data and send it to the LIS.
The use of the device eliminates the possibility of laboratory assistant error (human factor). The device turns on and off automatically, so the specialist takes the most minimal part in the diagnosis. The device is easy to operate and maintain. With the help of the equipment it is possible to carry out chromogenic and clotting analyses.
The device has a built-in special scanner, with the help of which a barcode is read and the patient’s biosample is automatically identified. In modern models of coagulometers, there is monitoring of the temperature regimes of samples and reagents.
Also, to simplify the work of the laboratory assistant, instructions for use are displayed on the monitor, which allows you to conduct research without errors and immediately obtain accurate results.