How blood is donated for clotting. Blood test for clotting and duration of bleeding Blood clotting as indicated in the tests

Blood clotting should be normal, so hemostasis is based on equilibrium processes. It is impossible for our valuable biological fluid to coagulate - this threatens with serious, deadly complications (). On the contrary, the slow formation of a blood clot can result in uncontrolled massive bleeding, which can also lead to the death of a person.

The most complex mechanisms and reactions, involving a number of substances at one stage or another, maintain this balance and thus enable the body to quickly cope on its own (without the involvement of any outside help) and recover.

The rate of blood clotting cannot be determined by any one parameter, because many components are involved in this process, activating each other. In this regard, blood coagulation tests are different, where the intervals of their normal values ​​mainly depend on the method of conducting the study, and in other cases, on the sex of the person and the days, months, and years he has lived. And the reader is unlikely to be satisfied with the answer: Blood clotting time is 5-10 minutes". A lot of questions remain...

Everyone is important and everyone is needed

Stopping bleeding is based on an extremely complex mechanism, which includes many biochemical reactions, which involves a huge number of different components, where each of them plays a specific role.

blood coagulation pattern

Meanwhile, the absence or inconsistency of at least one coagulation or anticoagulation factor can upset the whole process. Here are just a few examples:

• An inadequate reaction from the side of the walls of the vessels violates the platelets - which “feels” the primary hemostasis;
• The low ability of the endothelium to synthesize and secrete inhibitors of platelet aggregation (the main one is prostacyclin) and natural anticoagulants () thickens the blood moving through the vessels, which leads to the formation of clots in the bloodstream that are absolutely unnecessary for the body, which for the time being can calmly “sit” attached to the wall of which or a vessel. These become very dangerous when they break off and begin to circulate in the bloodstream - thereby creating the risk of a vascular accident;
• The absence of such a plasma factor as FVIII is due to a sex-linked disease - A;
• Hemophilia B is detected in a person if, for the same reasons (a recessive mutation on the X chromosome, which, as is known, there is only one in men), Christman factor deficiency (FIX) occurs.

In general, it all starts at the level of the damaged vascular wall, which, by secreting the substances necessary to ensure blood clotting, attracts platelets circulating in the bloodstream - platelets. For example, “inviting” platelets to the accident site and promoting their adhesion to collagen, a powerful stimulator of hemostasis, must start its activity in a timely manner and work well so that in the future one can count on the formation of a full-fledged plug.

If platelets use their functionality at the proper level (adhesive-aggregation function), other components of primary (vascular-platelet) hemostasis quickly come into play and form a platelet plug in a short time, then in order to stop the blood flowing from the vessel of the microvasculature , you can do without the special influence of other participants in the blood coagulation process. However, for the formation of a full-fledged plug capable of closing an injured vessel, which has a wider lumen, the body cannot cope without plasma factors.

Thus, at the first stage (immediately after the injury of the vascular wall), successive reactions begin to take place, where the activation of one factor gives impetus to bringing the rest into an active state. And if something is missing somewhere or the factor turns out to be untenable, the process of blood coagulation slows down or breaks off altogether.

In general, the clotting mechanism consists of 3 phases, which should provide:

• The formation of a complex complex of activated factors (prothrombinase) and the conversion of a protein synthesized by the liver - into thrombin ( activation phase);
• The transformation of the protein dissolved in the blood - factor I ( , FI) into insoluble fibrin is carried out in coagulation phase;
• Completion of the coagulation process by the formation of a dense fibrin clot ( retraction phase).

Blood clotting tests

A multi-stage cascade enzymatic process, the ultimate goal of which is the formation of a clot that can close the “gap” in the vessel, will surely seem confusing and incomprehensible to the reader, so it will be sufficient to remind that this mechanism is provided by various coagulation factors, enzymes, Ca 2+ (ions calcium) and a variety of other components. However, in this regard, patients are often interested in the question: how to detect if something is wrong with hemostasis or to calm down, knowing that the systems are working normally? Of course, for such purposes, there are tests for blood clotting.

The most common specific (local) analysis of the state of hemostasis is considered to be widely known, often prescribed by therapists, cardiologists, as well as obstetrician-gynecologists, the most informative.

Meanwhile, it should be noted that carrying out such a number of tests is not always justified. It depends on many circumstances: what the doctor is looking for, at what stage of the cascade of reactions he focuses his attention, how much time is available to medical workers, etc.

Simulation of the external pathway of blood clotting

For example, an extrinsic clotting activation pathway in the laboratory can mimic what the medical profession calls Quick Prothrombin, Quick Test, Prothrombin Time (PTT), or Thromboplastin Time (all different names for the same test). This test, which depends on factors II, V, VII, X, is based on the participation of tissue thromboplastin (it joins citrate recalcified plasma during work on a blood sample).

The limits of normal values ​​for men and women of the same age do not differ and are limited to the range of 78 - 142%, however, in women who are expecting a child, this figure is slightly increased (but slightly!). In children, on the contrary, the norms are within the limits of smaller values ​​and increase as they approach adulthood and beyond:

Reflection of the internal mechanism in the laboratory

Meanwhile, in order to determine a violation of blood clotting due to a malfunction of the internal mechanism, tissue thromboplastin is not used during the analysis - this allows the plasma to use only its own reserves. In the laboratory, the internal mechanism is traced, waiting for the blood taken from the vessels of the bloodstream to clot itself. The onset of this complex cascade reaction coincides with the activation of the Hageman factor (factor XII). The launch of this activation is provided by various conditions (contact of blood with a damaged vessel wall, cell membranes that have undergone certain changes), therefore it is called contact activation.

Contact activation also occurs outside the body, for example, when blood enters an alien environment and comes into contact with it (contact with glass in a test tube, instruments). The removal of calcium ions from the blood does not affect the launch of this mechanism in any way, however, the process cannot end with the formation of a clot - it breaks off at the stage of factor IX activation, where ionized calcium is no longer enough.

The time of blood clotting or the time during which it, while in a liquid state, pours into the form of an elastic clot, depends on the rate of conversion of the fibrinogen protein dissolved in plasma into insoluble fibrin. It (fibrin) forms threads that hold red blood cells (erythrocytes), causing them to form a bundle that closes the hole in the damaged blood vessel. Blood clotting time (1 ml taken from a vein - Lee-White method) in such cases is limited on average to 4-6 minutes. However, the blood coagulation rate, of course, has a wider range of digital (temporary) values:

1. Blood taken from a vein goes into the form of a clot from 5 to 10 minutes;
2. The Lee-White clotting time in a glass tube is 5-7 minutes, in a silicone tube it is extended to 12-25 minutes;
3. For blood taken from a finger, indicators are considered normal: the beginning - 30 seconds, the end of bleeding - 2 minutes.

An analysis that reflects the internal mechanism is turned to at the first suspicion of gross violations of blood coagulability. The test is very convenient: it is carried out quickly (until the blood flows or forms a clot in the test tube), it does without special reagents and sophisticated equipment, and the patient does not need special preparation. Of course, blood clotting disorders detected in this way give reason to assume a number of significant changes in the systems that ensure the normal state of hemostasis, and force further research to identify the true causes of the pathology.

With an increase (lengthening) of the blood clotting time, one can suspect:

• Deficiency of plasma factors designed to ensure coagulation, or their congenital inferiority, despite the fact that they are at a sufficient level in the blood;
• Serious pathology of the liver, resulting in functional failure of the parenchyma of the organ;
• (in the phase when the ability of blood to clot is on the wane);

Blood clotting time is lengthened in cases of using heparin therapy, so patients receiving this drug have to take tests that indicate the state of hemostasis quite often.

The considered indicator of blood clotting reduces its values ​​(shortened):

• In the phase of high coagulation () DIC;
• In other diseases that caused a pathological state of hemostasis, that is, when the patient already has blood clotting disorders and is assigned to a group of increased risk of blood clots (thrombosis, etc.);
• In women who use for contraception or for the purpose of treatment for a long time, oral agents containing hormones;
• In women and men taking corticosteroids (when prescribing corticosteroid drugs, age is very important - many of them in children and the elderly can cause significant changes in hemostasis, therefore they are prohibited for use in this group).

In general, the norms differ little

Indicators of blood coagulation (norm) in women, men and children (meaning one age for each category), in principle, differ little, although individual indicators in women change physiologically (before, during and after menstruation, during pregnancy), therefore, the sex of an adult is still taken into account in laboratory studies. In addition, in women during the period of bearing a child, individual parameters should even shift somewhat, because the body has to stop bleeding after childbirth, so the coagulation system begins to prepare ahead of time. An exception for some indicators of blood coagulation is the category of children in the first days of life, for example, in newborns, PTT is a couple of times higher than in adult males and females (the norm for adults is 11-15 seconds), and in premature babies, the prothrombin time increases for 3 - 5 seconds. True, already somewhere by the 4th day of life, PTV decreases and corresponds to the norm of blood clotting in adults.

To get acquainted with the norm of individual indicators of blood coagulation, and, possibly, to compare them with their own parameters (if the test was carried out relatively recently and there is a form with a record of the results of the study on hand), the table below will help the reader:

In conclusion, I would like to draw the attention of our regular (and new, of course) readers: perhaps reading the review article will not be able to fully satisfy the interest of patients affected by hemostasis pathology. People who first encountered a similar problem, as a rule, want to get as much information as possible about systems that provide both stopping bleeding at the right time and preventing the formation of dangerous clots, so they start looking for information on the Internet. Well, you should not rush - in other sections of our website, a detailed (and, most importantly, correct) description of each of the indicators of the state of hemostasis is given, the range of normal values ​​\u200b\u200bis indicated, and indications and preparation for analysis are also described.

Video: just about blood clotting

Video: reportage on blood clotting tests

One of the presenters will answer your question.

At the moment, answers questions: A. Olesya Valerievna, candidate of medical sciences, teacher of a medical university

The blood coagulation system is a powerful defense mechanism that prevents the human body from losing blood. Malfunctions in this system are a serious cause for concern. Any deviations of the blood test for coagulability from the norm indicate pathology. These can be harbingers of diseases such as heart attack, stroke, hemophilia, liver disease.

Purpose

A blood test for clotting may be prescribed in the following cases:

• diseases;
• unmotivated thrombosis;
• upcoming surgery (in order to obtain information about the coagulation system).

The main functions of the human blood coagulation system are to stop bleeding and maintain the blood in a liquid state. Maintaining these functions provides a complex mechanism. To study the processes of blood coagulation, there are many methods that allow you to evaluate the entire coagulation system, the amount and activity of specific substances, to identify why the system failed. For research, several methods are usually chosen that provide detailed information. One of the diagnostic methods is.

The method according to Sukharev has been widely used to determine the rate of blood clotting. The results of this analysis do not inform about the violation of the blood coagulation mechanism in general, but show whether the body can protect itself in case of blood loss.

• Hereditary diseases ─ hemophilia, von Willebrand disease.
• Vitamin K deficiency.
• Liver diseases ─, cirrhosis, fatty liver, carcinoma.
• Thrombocytopenia ─ .
• Long-term use of anticoagulants (blood thinners), for example, in the treatment of thrombophlebitis.
• Anemia.

Increased blood clotting can lead to blood clots in the blood vessels (veins). This condition poses a serious threat to life, since a blood clot can come off under the influence of blood flow. Moving along the venous bed, a thrombus is able to clog any vessel of a smaller diameter. It is impossible to trace the movement of a detached thrombus. For example, thrombosis of the coronary vessels of the heart inevitably leads to.

Reduced blood clotting leads to causeless bleeding of wounds, even small ones (scratches). With bruises and injuries, bruises and extensive hematomas may appear on the body. You may also experience bleeding gums. Reduced blood clotting is especially dangerous during surgery. Since the blood does not clot, the patient during surgery may lose a large amount of blood that is incompatible with life.

Causes of violations of blood clotting in the body can be physiological. During pregnancy, blood clotting parameters may deviate from the norm. This is due to the fact that during pregnancy a woman's blood volume increases by 20-25% and the uteroplacental circulation is formed.

A blood test for clotting is done only if there are grounds for this, and only as prescribed by a doctor.

If there is information about a genetic predisposition to hereditary blood diseases in the anamnesis of a pregnant woman, then after childbirth, a newborn may be prescribed a coagulation test.

This is especially true for . This genetic disease affects only boys. Girls are carriers of the hemophilia gene, and the disease does not manifest itself in them. Blood incoagulability in humans is very dangerous in childhood, since this is a period of increased traumatism. Minor trauma and violation of the integrity of the skin (abrasions, scratches) can lead to large blood loss. Severe bruises and unsuccessful falls can cause bleeding in the internal organs.

If poor blood clotting is suspected, the importance of taking tests becomes essential. Timely identification of problems will allow you to quickly take measures to eliminate blood clotting disorders. It will also prevent possible complications.

Training

In order for the reliability of the results not to be distorted and to be more accurate, a blood clotting test should be done on an empty stomach and in the morning. Before the study, it is not recommended to drink juices and sugary drinks, you can only drink water. To conduct research, they do it, more often from a finger.

Sukharev's method

This is a simple Sukharev method like a blood test, the essence of which is to determine the time interval between blood sampling and the onset of thickening. A special glass capillary is filled with the required amount of blood and placed in a tripod (Panchenkov's apparatus). The capillary with blood sways to the sides at a certain angle until the clotting process begins (the blood thickens and stops moving in the test tube). Time is recorded with a stopwatch. Indicators of the norm of blood clotting 3-5 minutes.

Coagulogram

A coagulogram is a set of tests. These tests examine the main indicators of the blood clotting system:

• specific blood proteins (fibrinogen, prothrombin);
• ─ this is a group of specific antibodies;
• TV ─ thrombin time;
• APTT is blood clotting time.

Deciphering blood coagulation tests is done by a doctor. In each individual clinic, different research methods are carried out. Indicators of the norm of blood coagulability differ, depending on the chosen method.

If you are taking medication, then when preparing to take a blood test for clotting, tell your doctor about it. This is due to the fact that some medications can distort the results of the study.

Video - Deciphering a blood test:

Nature gave the blood a special property - to coagulate, if not for this, even a slight tissue damage would end in death - a person would simply die from blood loss. But with some pathologies, this process is disrupted. Having passed an analysis for blood clotting and learning how the hemostasis system works, one can judge the presence of many diseases in the body.

Determination of blood clotting ability is called a coagulogram (hemostasiogram). The study is prescribed to identify a number of pathologies (hemophilia, cancer, thrombosis, liver disease, kidney disease, etc.) and before surgery or childbirth.

Normally, hemocoagulation should take place only outside the body, otherwise the resulting clots will travel through the vessels to the heart, lungs or brain, forming blood clots and causing ischemia, heart attacks and strokes.By donating blood for clotting, you can determine its ability to coagulate (clotting). This helps the doctor evaluate the risk of bleeding or blood clots.

Types of laboratory tests for coagulation

Blood clotting test includes the following indicators:

• fibrinogen level This substance is a protein produced by the liver. In a healthy person, fibrogen is 2-4 g / l.
• Antithrombin III. E the regulator of hemocoagulation. The antithrombin index is 75-125% in adults, 80-120% in children older than a month, and 30-80% in newborns.
• Prothrombin index (PTI) . The percentage of the time of hemocoagulation in a particular person with a similar indicator in the control sample. Normal PTI is 93-107%.
• thrombin time. In healthy people, it is from 14 to 20 seconds. During this period, prothrombin must be transformed into thrombin. The result may change under the influence of certain drugs, such as aspirin, or warfarin. The thrombin time (PT) test measures how well a person's blood is clotting.
• Activated partial thromboplastin time (APTT) . The indicator is used to control the process of hemocoagulation in patients who are prescribed heparin and in the diagnosis of DIC. Normally, this indicator is 29-39 seconds.
• The period (time) of bleeding. Indicates how quickly the blood will stop if the integrity of small vessels is violated. To do this, a puncture is made on the patient's finger and the time is recorded. Normally, it is 2-3 minutes.
• Clotting time. It is determined by the time interval between blood sampling and the formation of a clot. In healthy people, this process takes 2 to 5 minutes.
• D-dimer . This substance is formed as a result of the decomposition of fibrin. Normally, this indicator should be no more than 250 mcg / l (0.25 mcg / ml).

How to donate blood for clotting

Determination of bleeding time is carried out using capillary blood, for other coagulation tests, material must be taken from a vein.

Studies are carried out on an empty stomach, before analysis, you can only drink water. If you are taking any medications, you should tell your doctor about it, as some medications can affect the results.

By regularly taking tests for a hemostasiogram, you can timely diagnose many dangerous ailments.

Increased blood clotting and thrombosis

Many factors can lead to increased blood clotting, restriction or blockage of blood flow, and as a result, thrombosis. Blood clots can travel through the arteries and veins, causing serious consequences up to sudden death from an embolism.

Indications for examination

Normal blood clotting is 2-5 minutes (according to Sukharev). An analysis to determine this indicator (coagulogram, hemostasiogram) is prescribed for:

• diseases of internal organs;
• suspicion of hereditary hemostatic pathologies;
• pregnancy;
• varicose veins, thrombosis;
• diabetes mellitus;
• the appointment of coagulants;
• during the preoperative and postoperative period.

Risk factors

Increased hemocoagulation often occurs when:

• increased number of blood cells and hemoglobin, irradiation, oncological diseases;
• hyperfunction of the spleen, acidification and dehydration of the body, most often associated with poor bowel function;
• increased consumption of sugar and carbohydrates;
• overweight, pregnancy, prolonged bed rest, sedentary lifestyle and sedentary work;
• lack of specific hormones and enzymes, use of birth control pills or hormone replacement therapy.

Sometimes the tendency to increased clotting is congenital. This pathology is called thrombophilia. It is caused by a congenital decrease in the level of anticoagulants C and S, antithrombin III, coagulation factor VII, cofactor heparin II, dysfibrinogenemia, sickle cell anemia, hyperlipoproteinemia, increased activity of Hageman factors, Rosenthal and antihemophilic globulin. With this pathology, patients note similar cases in close relatives. Sometimes hereditary thrombophilias cause miscarriages in women.

Thickening of the blood in old age threatens to disrupt the activity of the brain, and in pregnant women it can adversely affect the condition of the mother and fetus. Poor rheology leads to ischemia of organs and tissues, which negatively affects the state of the whole organism.

How to suspect increased clotting

• A sign indicating increased hemocoagulation is thrombosis. If you notice painful bluish "vessels" or nodules on the limbs, this is an occasion to consult a doctor and be examined for blood clotting indicators.
• Another symptom that should alert is problems with the work of the heart. They should encourage you to get tested.

If the coagulogram parameters do not correspond to the norm, treatment should be started urgently in order to prevent thromboembolism.

Diseases accompanied by increased blood clotting

• Atherosclerosis. With atherosclerosis, plaques form inside the arteries. Over time, the plaque can rupture and platelets form clots at the site of injury.
• Vasculitis causes vascular inflammation, platelet aggregation and, as a result, an increase in coagulation parameters.
• Diabetes causes plaque to build up in the arteries, which is why nearly 80 percent of people with the condition eventually die from clotting and ischemia-related causes.
• In heart failure, this organ cannot pump enough blood to meet the needs of the body, its circulation slows down, it thickens and blood clots appear.
• High blood clotting is often observed in patients with varicose veins. In this case, blood clots have to be “thinned” with the help of special preparations in order to prevent the appearance of gangrene and necrosis associated with poor blood flow.
• This indicator also increases with some infectious diseases, especially those accompanied by fever. In this case, the blood becomes viscous, so patients are prescribed plenty of fluids and intravenous infusions of solutions.

Elevated coagulation parameters are very dangerous, as this condition threatens with serious complications and serious consequences.

Decreased blood clotting

Blood clotting is a complex, delicately balanced process that protects the body from blood loss. As a result of various pathologies, conditions can occur that lead to impaired hemocoagulation and serious consequences.

How to suspect deterioration of coagulation hemostasis

The first signs pointing topoor blood clottingthere are prolonged bleeding with small skin lesions or after injections. Normally, cuts or injections should not bleed for more than 3-5 minutes, but in the presence of pathology, this time can increase significantly. Sometimes under the skin in such people appear hemorrhages.

Another symptom indicating this condition is prolonged nosebleeds that are difficult to stop. Women with impaired hemocoagulation may experience menorrhagia and metrorrhagia. Sometimes blood traces can even be present in the urine and feces.

When these symptoms appear, it is recommended to donate blood for a coagulogram. The studies carried out by our specialists will reveal violations of coagulation hemostasis. All analyzes are carried out using modern equipment and reagents.

Reasons for the deterioration of hemocoagulation

Medications

• Coumarin group drugs reduce coagulation, as they are vitamin K antagonists. These drugs are used to protect against thrombosis after major operations, but if used incorrectly, these substances can significantly impair blood clotting.
• Aspirin, often used for colds and heart conditions, taken in high doses, can also cause a decrease in clotting.
• In some cases, this effect gives a combination of several drugs that are not recommended to be taken together.

In such cases, after determining the clotting time and duration of bleeding, the patient is prescribed vitamin K, which plays an important role in the process of hemostasis. Patients are advised to eat green vegetables (cabbage and spinach), eggs, milk and cereals, eliminating the lack of this vitamin.

hereditary diseases

• Hemophilia . This disease is inherited and affects only boys. In patients, symptoms of decreased blood clotting appear in early childhood. With this disease, various coagulation factors may be absent, so the disease can be more or less severe. Patients are treated by a hematologist for life. Replacement therapy, blood transfusions and restriction of motor activity are carried out.
• von Willebrand syndrome also characterized by a decrease in coagulability, but both men and women suffer from it. For the treatment of patients, tranexamic acid, desmopressin are used and blood transfusions are performed.

Other pathologies

A decrease in the number of platelets (thrombocytopenia) occurs with various anemic conditions, leukemia, after radiation therapy, viral infections, antibiotics and some other drugs. This condition can cause diseases of the liver, kidneys and spleen. This condition is treated with the introduction of special blood products.

Another reason for impaired hemocoagulation is liver disease, due to which the synthesis of substances responsible for proper hemostasis is disrupted. A decrease in PTI and a prolongation of blood clotting time are considered as an indirect sign of hepatitis.

There may be a decrease in coagulogram parameters after operations accompanied by profuse blood loss. This condition does not pose a danger to human health, and passes on its own.

Properly selected treatment with a decrease in hemocoagulation will help to avoid severe blood loss and serious complications.

Indicators of blood clotting during pregnancy

Every pregnant woman who is registered in the antenatal clinic must be sent for an analysis called a hemostasiogram. The results of the hemostasiogram make it possible to determine the presence of disorders in the blood coagulation system, if any.

The role of hemostasis during pregnancy

Hemostasis acts as a "thickener" of blood, thanks to this system, a person avoids significant blood loss in cases of vascular damage. In tandem with the coagulation system, an anticoagulant - a “thinner” of the blood - acts in the body. If the balance is disturbed, the systems fail, as a result, the blood can become too viscous, which leads to the formation of blood clots, or too liquid, in both cases, the blood clotting time changes.

What is dangerous violation of hemostasis for pregnant women

Increased blood clotting during pregnancycan provoke DIC, in which the blood in the vessels, thickening, causes a violation of placental blood flow. The condition is dangerous for the baby, since he cannot receive good nutrition, which immediately affects his development. In severe cases, pregnancy may freeze, as a result, the fetus dies. Timely delivery of an analysis for hemostasis gives a great chance to avoid such complications.

Violations of the coagulation system can cause premature detachment of the placenta, even in the case of its normal location.

When to take a blood clotting test

It is recommended to make a hemostasiogram before the expected pregnancy. In case of poor performance, it will be possible to undergo a course of therapy, which the doctor will select individually. The risk group, which shows a mandatory preliminary examination for coagulability, includes women:

• having relatives who have had a stroke, heart attacks, thrombosis, varicose veins;
• who have had a miscarriage or missed pregnancy;
• athletes and hard workers.

During pregnancy, it is also necessary to undergo a diagnosis, especially if the doctor diagnoses:

• habitual miscarriage - the presence of two or more unsuccessful pregnancies (miscarriage, fading);
• preeclampsia - swelling of the extremities, protein in the urine, high blood pressure;
• threatened miscarriage.

If there is preeclampsia during pregnancy, blood clotting increases in 70% of cases, which aggravates the treatment. You can also prevent the situation by passing the analysis and undergoing therapy in a timely manner.

Methods of treatment of hemostasis disorders in pregnant women

With timely diagnosis of hemostasis disorders, many complications of pregnancy can be avoided. In European medical practice, DIC is treated with low molecular weight heparins, which are absolutely safe for the fetus. You can be treated with the permission of a gynecologist at home, subject to control tests (every 2 weeks). At the same time, doctors prescribe antioxidants, aspirin-containing drugs, folic acid, vitamin B.

If the patient does not have the opportunity to buy expensive low molecular weight heparins, the specialist can replace them with conventional heparin. In this case, strict control over the results and the condition of the pregnant woman is necessary, since it is very difficult to choose the dose of an unfractionated drug immediately, you will have to visit the clinic twice a week. For control, you need to periodically take a blood coagulation test.

Coagulogram (syn.: hemostasiogram) is a set of blood parameters that characterize its ability to coagulate. Blood clotting is one of the many protective functions that support the normal functioning of the body.

The coagulogram, which can be basic and extended, should be evaluated together with a general blood test, including the determination of the number of platelets, erythrocytes, hemoglobin, and hematocrit. All indicators of the coagulogram are indicative. If pathology is detected in the baseline study, an extended version is performed, which may include an assessment of blood clotting factors.

Acceleration of coagulation, the so-called hypercoagulability, leads to increased thrombosis, which is fraught with the development of thrombosis and thromboembolism. A decrease in coagulability, or hypocoagulation, carries the risk of developing uncontrolled bleeding.

How is the procedure?

Blood sampling is carried out from the cubital vein on an empty stomach in the morning.

Indications for the appointment of a blood test for clotting

• monitoring the state of the hemostasis system;
• scheduled examination before surgery;
• pregnancy;
• gestoses;
• monitoring anticoagulation therapy;
• monitoring of antiplatelet therapy;
• venous disease;
• DIC;
• taking medications (oral contraceptives, glucocorticosteroids, anabolics);

Bleeding time

Bleeding time is the main indicator of the state of the hemostasis system, its vascular-platelet link. For research, the earlobe is pierced with a scarifier and the time after which the blood stops is fixed. Only the elongation of the indicator is evaluated. The test should not be used for preoperative routine screening.

Interpretation of results

Prolongation of bleeding time:

• thrombocytopenia;
• thrombocytopathy;
• hemophilia;
• alcoholic liver disease;
• cirrhosis of the liver;
• hemorrhagic fevers;
• overdose of anticoagulants and antiplatelet agents.

Reduce bleeding time:

• has no diagnostic value;
• technical error during the study.

APTT

Activated partial thromboplastin time (APTT) is an indicator of the effectiveness of plasma factors in stopping bleeding, characterizes coagulation (plasma) hemostasis and is the most sensitive and accurate indicator of the hemostasiogram. The value of APTT, first of all, depends on the reagents-activators used by the doctor, and the indicator may vary in different laboratories.

Interpretation of results

APTT prolongation:

• insufficiency of II, V, VIII, IX, X, XI, XII coagulation factors;
• fibrinolysis;
• DIC, 2nd and 3rd phases;
• heparin therapy (fraxiparine and analogues);
• severe liver disease;
• hemophilia A, B, C;
• Hageman's disease;
• antiphospholipid syndrome (APS);
• infusions of rheopolyglucin, hydroxyethyl starch preparations.

Shortening of APTT:

• DIC, 1st phase;
• thrombosis;
• thromboembolism;
• inaccurate blood sampling for analysis;
• physiological pregnancy.

Prothrombin time according to Quick and INR

Prothrombin time (PTT)- this is the time of formation of a thrombin clot, if calcium and thromboplastin are added to the plasma, it characterizes coagulation (plasma) hemostasis. The indicator reflects the 1st and 2nd phase of plasma coagulation and the activity of the II, V, VII and X factors. The test is used to evaluate the external mechanism of blood clotting. Therapy with anticoagulants is considered effective if the PTT increases at least 1.5-2 times.

Interpretation of results

Shortening PTV:

• DIC;
• last weeks of pregnancy;
• taking oral contraceptives;
• treatment with prothrombin complex factor concentrates.

PTV extension:

• deficiency or anomaly of prothrombin complex factors (VII, X, V, II);
• taking anticoagulants of indirect action;
• diseases of the liver and biliary tract;
• treatment with unfractionated heparin;
• infusions of rheopolyglucin, hydroxyethyl starch preparations;
• the presence of lupus anticoagulant in the blood;

INR(International Normalized Ratio), or prothrombin ratio, is the ratio of the patient's PTT to the PTT of normal plasma as an international sensitivity index. This indicator is a mathematical correction value by which the PTV is standardized in order to compare the results obtained in different laboratories. The main purpose of determining the INR is to control the intake of indirect anticoagulants by patients. Normally, the INR approaches 1. The therapeutic range of INR 2-3 against the background of therapy with indirect anticoagulants provides the prevention of thrombosis without increasing the risk of bleeding.

Interpretation of results

Increase in PTT time and INR:

• cirrhosis of the liver;
• chronic hepatitis;
• vitamin K deficiency;
• amyloidosis;
• DIC;
• hereditary deficiency of II, V, VII and X coagulation factors;
• a decrease in the level of fibrinogen or its absence;
• treatment with coumarin derivatives.

Decreased PTT and INR:

• thrombosis;
• thromboembolism;
• activation of fibrinolysis;
• increased activity of coagulation factor VII.

thrombin time

Thrombin time (TT) is the third most important basic coagulation test that characterizes the final stage of the coagulation process - the conversion of fibrinogen into fibrin under the action of thrombin. It is always determined together with APTT and PTT to control fibrinolytic and heparin therapy, to diagnose congenital fibrinogen pathologies. The definition of TV is used to detect dysfibrinogenemia and assess the anticoagulant activity of the blood.

Interpretation of results

TV extension:

• hypofibrinogenemia: a decrease in the concentration of fibrinogen (below 0.5 g / l) or its complete absence;
• DIC;
• therapy with fibrinolytic drugs;
• autoimmune diseases;
• chronic liver diseases;
• acute DIC;
• the presence of direct-acting anticoagulants in the blood;
• paraproteinemia;
• uremia;
• multiforme myeloma;
• incorrect blood sampling for research.

Shortening TV:

• treatment with heparin and inhibitors of fibrin polymerization;
• hyperfibrinogenemia (fibrinogen 6.0 g/l and above);
• acute and subacute DIC, initial phases.

fibrinogen

Fibrinogen - according to the international nomenclature, factor I (first) of the plasma coagulation system. The quantitative determination of fibrinogen by the Clauss method is the basic test for the study of hemostasis. Fibrinogen belongs to the acute phase proteins, its concentration increases in plasma during infections, trauma, and stress. An increase in plasma fibrinogen concentration, even within the reference values, correlates with an increase in the risk of complications of cardiovascular diseases.

Interpretation of results

Content increase:

• severe infectious diseases;
• in patients with cardiovascular diseases precedes the development of myocardial infarction and stroke;
• pregnancy;
• after surgical operations;
• amyloidosis;
• menstruation;
• treatment with heparin and its low molecular weight analogues, estrogens, oral contraceptives;
• various renal pathologies.

Content reduction:

• congenital and hereditary deficiency;
• acute DIC;
• alcoholic liver disease;
• cirrhosis of the liver;
• prostate cancer with metastases;
• condition after bleeding;
• therapy with anabolics, androgens, barbiturates, fish oil, valproic acid, inhibitors of fibrin polymerization;
• heparin intoxication.

Antithrombin III

Antithrombin III (AT III) is a physiological anticoagulant, an inhibitor of plasma coagulation factors, and a plasma cofactor of heparin. It has the main inhibitory (anticoagulant) effect on the processes of blood coagulation. The test is used to monitor heparin treatment.

Interpretation of results

Increasing the level of AT III:

• severe infectious diseases;
• acute hepatitis;
• vitamin K deficiency;
• cholestasis;
• severe acute pancreatitis;
• pancreas cancer;
• menstruation;
• treatment with anabolic steroids, indirect anticoagulants.

Decrease in the level of AT III:

• congenital and hereditary deficiency of AT III;
• alcoholic liver disease;
• cirrhosis of the liver;
• acute DIC;
• last trimester of pregnancy;
• after surgical operations;
• sepsis;
• thrombosis and thromboembolism;
• sepsis;
• treatment with heparin and fibrin polymerization inhibitors, oral contraceptives, corticosteroids;
• nephrotic syndrome;
• lung carcinoma;
• polytrauma;
• gestosis.

D-dimers

D-dimers are specific fibrin degradation products that are part of a thrombus. Refers to tests of activation of blood coagulation (procoagulation). The concentration of D-dimers in serum is proportional to the activity of fibrinolysis and the amount of fibrin lysed. This test allows you to judge the intensity of the processes of formation and destruction of fibrin clots. Elevated levels of D-dimer are detected in a variety of conditions associated with the activation of coagulation.

Interpretation of results

Increasing the level of the indicator:

• numerous liver diseases;
• extensive hematomas;
• myocardial infarction;
• long history of smoking;
• DIC;
• seropositive rheumatoid arthritis;
• sepsis;
• pregnancy;
• age over 80;
• oncological diseases;
• thrombolytic therapy.

RFMC

Soluble fibrin-monomeric complexes (SFMK) are intermediate products of fibrin clot disintegration due to fibrinolysis, refers to tests of activation of blood coagulation (paracoagulation). RFMK is very quickly excreted from the blood plasma, so it is very difficult to determine. The RFMK test is mainly used for the early diagnosis of DIC.

Interpretation of results

Increasing the level of the indicator:

• DIC;
• arterial and venous thrombosis and thromboembolism of various localization;
• postoperative period of extensive surgical interventions;
• complicated pregnancy;
• physiological pregnancy;
• neonatal period;
• acute and chronic renal failure;
• sepsis;
• systemic connective tissue diseases;
• physical and psychological stress.

Norms

For preventive purposes or to determine the causes of any symptoms of diseases, a number of laboratory tests are usually prescribed. At the same time, blood clotting is often determined - the norm of this indicator indicates the normal functioning of the liver, vascular patency and the flow of biological fluid in the veins. Any deviations indicate persistent hemostasis disorders that need to be treated.

Blood clotting parameters - normal

• pregnancy;
• preoperative studies and the period after surgical interventions;
• liver disease;
• pathology of the vascular system;
• tendency to thrombosis;
• autoimmune diseases.

It is possible to determine which norm of blood coagulation indicators is violated and characterizes each of the listed conditions using the following values:

1. The time it takes for blood to clot. It is calculated from the moment the biological fluid was taken for analysis until the start of clotting. In a healthy body, this time is from 5 to 7 minutes. This indicator indicates the activity of platelets, plasma factors, as well as the functioning of the walls of blood vessels.
2. duration of bleeding. It is measured from the moment of damage to the skin to the cessation of bleeding from the wound. Normally, this value is no more than 5 minutes, it characterizes the state of the vascular walls, the balance of platelets and factor VII.
3. Partial active thromboplastin time. This indicator is designed to study the concentration of fibrinogen, as well as the level of activation of blood factors. The value does not depend on the number of platelets, the norm is from 35 to 45 seconds.
4. prothrombin time. This item allows you to find out how normal the content of proteins responsible for blood clotting (thrombin and prothrombin) is. In addition to the concentration, the analysis results must indicate the chemical composition and percentage of the measured values. Ideally, this time is from 11 to 18 seconds.

It is worth noting that the rate of blood clotting in pregnant women is somewhat different from the generally accepted indicators, since an additional circle of blood circulation appears in the body of the expectant mother - the uteroplacental one.

Blood clotting according to Sukharev - the norm

This analysis is carried out either 3 hours after the last meal, or on an empty stomach in the morning. Blood is taken from the finger of the hand and filled with a special container, called a capillary, up to the mark of 30 mm. Then, by means of a stopwatch, the time is calculated after which the liquid begins to fill the vessel more slowly, and therefore, to coagulate. The beginning of this process normally ranges from 30 to 120 seconds, the end - from 3 to 5 minutes.

Duque's blood clotting is normal

The study in question is performed using a Frank needle, which pierces the earlobe to a depth of 4 mm. Since the puncture is timed and every 15-20 seconds a strip of filter paper is applied to the wound. When red traces cease to remain on it, the analysis is considered completed and the blood clotting time is calculated. The normal rate is 1-3 minutes.

Blood clotting is higher or lower than normal

Deviations of the obtained values ​​of laboratory tests in one direction or another indicate the presence of diseases of the vessels and vascular walls, venous diseases, acquired or congenital pathologies of hemostasis, leukemia, hemophilia.