Tag analysis. Thromboelastography. What coagulogram parameters are needed for children and pregnant women?

The result of studying processes in the blood such as coagulation and the ability to dissolve blood clots (fibrolysis) is a thromboelastogram. It makes it possible to prevent pathologies in many areas of medicine.

The readings of the graphical curve made using the thromboelastgraph device are, of course, not enough to draw serious conclusions. However, based on the thromboelastogram, which is deciphered in the laboratory, the doctor may prescribe additional examination if necessary. If the thromboelastogram is not normal, other indicators characterizing hemostasis will most likely be needed.

Medicine has always felt the need for such indicators as the thromboelastograph device provides. However, until the 90s, he gave a very superficial understanding of the processes occurring in the blood, because he had low sensitivity. New generation thromboelastographs make it possible to detect vascular pathologies in the early stages.

The results of thromboelastogram are relevant in such areas of medicine as cardiology, gynecology, hematology, surgery, oncology, and neurology. It is very valuable that this study allows us to observe both links involved in the coagulation process: cellular and plasma hemostasis.

The first refers to the interaction of all blood cells with each other and in relation to a foreign body, and plasma shows the chain of all reactions: coagulation, fibrin formation and its breakdown. Since the entire process during the study is computerized, everything is recorded: how the clot behaves in whole blood, how in plasma, how in plasma with platelets.

Plasma hemostasis is otherwise called coagulation, therefore, as a result of testing, either the thromboelastogram shows the norm or records hypocoagulation, hypercoagulation. The terms “hypo” and “hyper” are understandable today even to a non-specialist. The first can lead to heavy bleeding, and the second to blood clots.

A laboratory test of hemostasis such as thromboelastography is very important in surgery when it comes to organ transplantation in the postoperative period after severe injuries accompanied by severe blood loss. Today such research is mandatory during pregnancy. Moreover, the norm may vary depending on the trimester.

When prescribing thromboelastography, the doctor has several goals:

Identification of disturbances in the general hemostasis system;

Admissibility of surgical intervention;

Monitoring the effectiveness of thrombolytic therapy.

Thromboelastogram (TEG) does not provide a picture of the condition of the vascular wall, but has a great advantage over other standard tests. She evaluates 4 main components of hemostasis at once, and does this in interaction.

Since cardiovascular diseases are becoming one of the leading diseases today, examination with a thromboelastograph is becoming increasingly important. The norm in this case does not depend on gender or age. One of the main indicators, R, denotes the time from the start of recording to phase 1 of coagulation and is normally equal to 12 minutes.

If the deviation is towards a decrease in this time, then we are talking about hypercoagulation. Otherwise, hypocoagulation is “obvious”. The optimal time for clot formation is designated “K” and is normally limited to 6 minutes. As in the example above, its shortening is hypercoagulable.

“MA” is the maximum amplitude, that is, the greatest distance by which the branches of the thromboelastogram can diverge (50 mm). "E" - maximum elasticity (100-150). The analysis only operates with numbers, and the possible causes of deviations, of course, are determined by the attending physician.

As a rule, drug treatment is selected to correct platelet activity. The study helps to select an individual dosage of antithrombotic drugs.

A normal level of coagulation is important for the full functioning of all internal organs. Therefore, deviations from the norm are not actually a disease, but only draw attention to existing or possible future problems.

Experts advise undergoing a thromboelastogram before any interventions in the body, including tooth extraction. Pregnant women need to do this three times during pregnancy. People with varicose veins, everyone over 40 - these are also risk categories.

This is especially important for pregnant women, since the amount of circulating blood increases many times over. Hypocoagulation is fraught with placental abruption. Long-term use of blood thinning medications can also cause poor clotting. Sometimes disorders have genetic or somatic causes.

Sometimes it makes sense to reconsider your diet. After all, the level of blood clotting can be regulated by nutrition. Thus, animal fats, buckwheat, bananas, vegetables and fruits of red and purple color help thicken the blood. Fish, citrus fruits, green tea, chocolate, and oats have the opposite effect. Drinking regimen is very important to thin the blood.

Thromboelastogram is a graphical representation of the dynamics of blood coagulation, which is used to carry out an integral assessment of hemostasis. The study is fast and accessible, so it is indispensable in emergency cases: when planning an operation, obstetric hemorrhage, or choosing hemostatic therapy.

Equipment for analysis is available in only a few laboratories in Moscow, and one of them is located in the International Life Center on Taganka. The price of TEG, or thromboelastography, at the Women's Medical Center is only 900 rubles.

Price for TEG analysis*

Who is prescribed thromboelastography and why?

Most often, the study is used in surgery, gynecology and anesthesiology. Thus, the use of thromboelastography on the eve of operations with possible blood loss can reduce the frequency of using fresh frozen donor plasma.

Thromboelastogram is prescribed for rapid assessment of blood clotting:

• on the eve of surgery or an invasive procedure - to predict the risk of bleeding and thrombosis;
• for the purpose of monitoring hemostatic or antiplatelet therapy, when selecting medications;
• for differential, comparative diagnosis of bleeding.

Thromboelastography is used to identify pathologies such as primary and secondary hyperfibrinolysis (high bleeding), hypocoagulation - “poor” blood clotting, thrombocytopenia and thrombocytosis - changes in the number of platelets in plasma, deficiency of the prothrombin complex, disseminated intravascular coagulation syndrome and combined hemostasis disorders.

Specialists

obstetrician-gynecologist, specialist in the field of clinical hemostasiology, professor, doctor of medical sciences, academician of the Russian Academy of Sciences, vice-president of the Russian Society of Obstetricians and Gynecologists, Honorary Professor of the University of Vienna (Austria)

Make an appointment

Advantages of thromboelastogram

The study allows us to assess the physical properties of a blood clot, the dynamics of hemostasis and identify hyperfibrinolysis - excessive formation of the enzyme plasmin, signaling a high risk of bleeding.

How to prepare for the test

The rules for collecting blood for thromboelastogram do not differ from other coagulation tests:

• Blood is drawn from a vein;
• The test is scheduled for the morning, after an 8-hour fast;
• in emergency cases, the study is carried out regardless of the time of day or meal;
• To monitor therapy with low molecular weight heparins, blood is taken 3-4 hours after injection.

How is thromboelastography done?

The study is carried out using a special device - a thromboelastograph. A few drops of blood (up to 0.4 ml) are placed in a cuvette with a cylinder. The physical strength of the clot is measured using the method of conventional mechanical vibrations. The amplitude of vibrations during the formation and dissolution of a clot is recorded by a digital system or computer.

During TEG, various coagulation activators are added to the cuvette to diagnose disorders of hemostasis mechanisms.

Decoding indicators

The main indicators of thromboelastogram are:

The interpretation of the thromboelastogram should be carried out by a hemostasiologist, since its results may change due to electrolyte disturbances, the effects of medications, recent surgery or underlying pathologies.

Where to get a thromboelastogram test in Moscow

TEG equipment differs from most automated blood analyzers: it has only 2-4 cuvettes, compared to 60-90 in standard medical devices. Such installations are available only in experimental laboratories - for example, in the Laboratory of Hemostasis Pathology at the MLC on Zemlyanoy Val.

To sign up for a TEG test, contact the administrator of the Women's Medical Center, or leave your contacts electronically on the website.

Thromboelastography is one of the methods that allows you to assess the state of the blood coagulation system based on examination of the clot. Particular attention is paid to its viscosity and elasticity. The main essence of the thromboelastogram is the assessment of hemostasis through an integral nature. This technique is able to show the results of the coagulation system, platelets, and it also evaluates the work of the fibrinolysis system and anticoagulation mechanisms. Information is obtained only based on the density of the clot. Doctors widely use this method of assessing hemostasis disorders to adjust treatment. The test has become widespread in all surgical specialties, that is, it is used by general and vascular surgeons, gynecologists, oncologists, as well as some therapeutic specialists - cardiologists, neurologists.

The basic operating principle of the device, called a thromboelastograph, is based on assessing the main physical properties of a blood clot. The biological material is placed in a cuvette – a cylindrical bowl. It is tilted from its axis by 4.45 degrees, in this position the device begins rotational movements. One rotation cycle lasts exactly 10 seconds.

A rod with an anchor is placed in the biological material. It is suspended on a special twisting thread. The torque of the cuvette cylinder is not initially transmitted to them. This occurs after clot formation and coagulation has begun. In order to form a clot, it is necessary to wait for some time after immersing the material in the cuvette.

As soon as the cup and the rod are connected by a clot, the recording of indicators begins, and the rod begins to transmit them. The result is determined by the strength of the connection of the apparatus units. It is important to consider that uncoagulated blood in no way transmits rotation, and the more the blood clot hardens, the greater the amplitude of movement.

An organized clot causes synchronous movement of the cuvette and the rod. Thus, if a dense clot has formed, the rod begins to rotate along with the cup. This is the maximum amplitude of the device.

It turns out that its angle of rotation depends on how dense the clot is formed. When lysis or another version of its destruction begins, or it contracts, the connections in the blood weaken, the joint work of the cup and the rod worsens, and accordingly, transmission also decreases.

The rotational motion of the rod is remodeled from mechanical vibrations into electrical signals. They are recorded using computers. As a result, the doctor receives information about the beginning of the formation of the very first fibrin threads, how a blood clot is formed, how dense it is, and how its destruction proceeds. Also, through this research method, the doctor assesses the state of hemostasis and receives all the necessary information about the coagulation system.

Using a computer to interpret the analysis allows you to record the kinetic changes of the blood clot, which can be assessed not only in whole blood, but also in plasma or platelet-rich plasma. We are talking about the formation of a blood clot, its destruction, and lysis.

Based on this, scientists came to the conclusion that using thromboelastography it will be possible to obtain information about the physical properties of a blood clot, which consists of blood cells and fibrin threads. At its core, the device for conducting this study measures the mechanical work of a thrombus or blood clot throughout the operation of the coagulation system. He begins recording the results from the very beginning of the start of coagulation, even before the appearance of the very first fibrin threads, evaluates the development and structure of the blood clot, as well as its destruction and lysis.

How is thromboelastography done?

Thromboelastography is a laboratory and instrumental method for studying the state of hemostasis. It involves taking blood from the patient, which makes the technique a laboratory one. Biological material is collected in the morning. It is important that the patient is fasting as this allows for more accurate results. After the blood has been obtained, the patient is released, since the procedure does not require his active participation.

Thromboelastogram parameters

The following thromboelastogram parameters are distinguished: CT, CFT, MCF, Ax, ML. Other main parameters are R, K, MA, E, T. There are also additional ones that include G, T, t, S. The name is formed from an English abbreviation.

1. CT or clotting time. This value refers to the time during which a blood clot began to form from the very start of the procedure. Expressed in seconds. This parameter depends on many factors, as well as the activity of the anticoagulation system and coagulation inhibitors.
2. CFT or clot formation time. Also expressed in seconds and includes the time from the start of the formation of a blood clot to the development of its density, equal to 20 millimeters. This parameter reflects the polymerization of fibrin, the work of the fibrin-stabilizing factor, the fixation of a blood clot by platelets and other formed elements.
3. MCF or maximum clot firmness. Displays the maximum amplitude as a function of thrombus density. Measured in millimeters. This parameter depends on the presence of fibrinogen and blood cells, that is, the substrates of a thrombus or clot.
4. Ah – represents the amplitude value. It is also the density of a blood clot. It is measured at different time periods of the study. For example, doctors evaluate the formation of a blood clot at the most critical levels of clotting or at the borders of normal. This allows you to obtain more information about the operation of the hemostasis system.
5. ML or maximum lysis – displayed when the clot begins to dissolve. The decrease in its density relative to the maximum is measured. The parameter is measured as a percentage. It depends on the degree of activity and adequacy of the anticoagulation system, fibrinolysis, making it possible to study this system.
6. R represents the reaction time from the start of fixation until the outcome branches expand by 1 mm. This is usually the time of the first phase of hemostasis.
7. K refers to the time of thrombus formation. It is calculated from the expansion of the dough branches by 1 mm to 20 mm. The duration is determined by the rate of thrombin formation. If it takes a long time, then K will also be high. The indicator indicates the rate of formation of a fibrin clot.
8. MA is the maximum amplitude, that is, the maximum divergence of the branches of the device. Indicates the density of the thrombus.
9. E – maximum elasticity. It is calculated based on the indicators described above.

Additional options include:

• G – time of complete coagulation, that is, the interval between the beginning of recording the results to the maximum amplitude of the device;
• T – allows you to characterize the productive phase of thrombus formation;
• t, S – calculated based on K, P and MA. Using them, you can find out the activity of formed elements and the quantitative content of fibrinogen.

Reference values

It is important to note that these values ​​may vary slightly as each laboratory performs the procedure on its own equipment. The norm is:

• R – 12 minutes, if the interval is shorter, then we are talking about hypercoagulation, if it is longer, on the contrary, it is about hypercoagulation, a high risk of blood clots, thrombosis;
• K – 6 minutes, hypercoagulation during shortening;
• MA – up to 50 millimeters;
• E – 100-150.

Interpretation of results

Thromboelastorgaphy is performed quite often in modern clinical practice. The study allows us to establish an increased risk for the occurrence of thrombosis, blood clots or other pathologies of the blood coagulation system. Taking into account the reference values, as well as the complexity of assessing the results of the manipulation, interpretation is carried out exclusively by an experienced doctor in order to prevent errors in deciphering the study.

The doctor also evaluates other parameters:

• APTT time;
• prothrombin time test;
• the amount of prothrombin, fibrinogen.

APTT - activated partial prothrombin time should always be performed in conjunction with other tests. The most informative is the prothrombin time test. But to obtain the maximum amount of information, the doctor needs to conduct not only a laboratory study, but also an instrumental one, which includes thromboelastography.

Mechanism of fibrin formation

Fibrin formation begins from the transformation of thrombin into fibrinogen. The next step is the formation of fibrin monomer under the influence of chemical reactions. From it appears the so-called soluble fibrin polymer, which, under the influence of blood clotting factor 13 (called fibrin-stabilizing factor-enzyme), is converted into fibrin.

The difference between a thromboelastogram and the main coagulogram tests

This technique allows you to evaluate those components that took part in the formation of thrombus - fibrin, thrombin, blood cells, especially platelets. It also does not involve centrifugation of biological material, which reduces the analysis time. The thrombus forms almost naturally, which is also an advantage.

Basic thromboelastogram tests

There are several tests that can better evaluate the hemostatic system.

1. Extem – extrinsic blood coagulation pathway, assessment of 1, 2, 5, 7 and 10 coagulation factors, fibrinolysis system, platelets.
2. Intem - also allows you to evaluate fibrinolysis and platelets, as well as factors 1, 2, 5, 8, 9, 10, 11, 12. If these tests are normal, then we can talk about normal hemostasis.
3. Fibtem - evaluates the work of fibrinogen during the formation of a blood clot, while the influence of platelets is not taken into account. This test is compared with Extem.
4. Aptem - allows you to determine the presence of hyperfibrinolysis.
5. Heptem – detects blood heparin.

The presence of thrombocytopenia will be indicated by a low amplitude at extem at the 10th minute, or a normal amplitude at the 10th minute at fibtem.

Hypofibrinogenemia

Hypofibrinogenemia is recorded when the amplitude decreases at the 10th minute of the extem and fibtem test results.

Indications for the use of thromboelastogram

The indication for an elastogram is an increased risk of thrombosis. Such patients are:

• those in need of emergency surgical care;
• when repeated surgery is necessary in a short period of time;
• performing surgical interventions on great vessels;
• patients who have undergone multivalve correction or ventricular replacement;
• decompensated heart failure;
• being on a heart-lung machine for more than three hours;
• increased bleeding after surgery.

Regular use of thromboelastography is not recommended.

Increasing and decreasing values, positive and negative results

The results are assessed based on reference values.

1. The normal reaction time is approximately 12 minutes, which corresponds in its value to the first phase of hemostasis. An increase in values ​​indicates hypocoagulation, a decrease indicates the opposite.
2. The clot forms in 6 minutes. The time depends on many factors, and the indicator itself characterizes the rate of fibrin formation. A decrease below normal indicates hypercoagulation.
3. The normal maximum amplitude does not exceed 5 cm. It allows you to assess the density of the blood clot. The indicator depends on the content of formed elements and fibrinogen.
4. The maximum elasticity is in the range of 100-150.

The doctor must take into account not only thromboelastography indicators for an adequate assessment of the hemostatic system and its correction. He should also conduct coagulation tests, which include measuring INR, APTT, prothrombin index and others to obtain the maximum amount of information.

Thromboelastography (TEG) is a method for assessing the state of the hemostatic system by studying the viscoelastic properties of the clot. The main essence of TEG is the integral nature of the assessment of the hemostatic system. The method demonstrates the result of the interaction of the coagulation cascade, platelets, anticoagulation mechanisms and the fibrinolysis system.

TEG was first described as a method by H. Harlet in 1948. In the past, this method was quite widely used in the laboratory, but it had a number of disadvantages (low sensitivity and reproducibility, the inability to detect minor disorders in the blood coagulation system, and to conduct an analytical assessment of identified disorders). Therefore, the method was suitable only for tentative identification of the most pronounced disorders of hemostasis and, partly, fibrinolysis. Since the beginning of the 90s of the XX century. There was a revival of TEG due to the emergence, first of all, of a completely new class of thromboelastographs. With their help, it is possible to identify early signs of intravascular coagulation and hypocoagulation caused by a deficiency of blood coagulation factors, diagnose platelet aggregation disorders, hyperfibrinolysis, and evaluate the effectiveness of anticoagulant and antiplatelet therapy.

The TEG method is now widely used to diagnose and select tactics for correcting disorders of the hemostatic system in surgery, obstetrics and gynecology, hematology, cardiology, oncology, neurology and cardiovascular surgery.

The principle of operation of a thromboelastograph is that it evaluates the physical properties of a blood clot using a special cylindrical cup (cuvette) into which a blood sample is placed. The cup makes rotational movements relative to its axis at an angle of 4°45`. Each rotation cycle lasts 10 s. A rod (with an anchor) immersed in the blood sample is suspended by a twisting thread. The torque of the rotating cup is transmitted to the rod immersed in the sample only after the clot formed due to fibrin-platelet bonds begins to connect the cup and rod together. The strength of these connections determines the angle of rotation of the rod: uncoagulated blood does not transmit rotation, a loose clot only partially transmits rotation, and an organized clot causes the rod to move synchronously with the cup. Thus, the angle of rotation of the rod directly depends on the strength of the formed clot. As soon as the clot begins to shrink or collapse (lysis), the bonds are broken, the interaction between the cup and the rod is weakened, and the transmission of motion from the cup to the rod is reduced.

The rotational movement of the rod is converted from a mechanical signal into an electrical signal, which is recorded using a computer. As a result, it is possible to measure the time at which the first fibrin strands begin to form, the kinetics of formation and the strength of the clot, and evaluate the process of its dissolution. The computerized thromboelastograph system automatically records clot kinetic changes that occur in a whole blood, plasma, or platelet-rich plasma sample, such as clot formation, retraction, and/or lysis.

Such images. The thromboelastograph monitors the physical properties of a blood clot, which consists of fibrin strands and blood cells. Essentially, the thromboelastograph measures the ability of a clot to perform mechanical work throughout the coagulation cascade: from the initiation of the blood clotting process to the appearance of the first fibrin strands and the development of clot structure, ending with clot lysis.

Basic (main) TEG parameters:
TEG technology allows the use of both native and sodium citrate-stabilized blood samples. With equal reliability of the results, the latter option is more convenient from a practical point of view. The use of citrated blood allows for a very significant sample exposure (within 1 hour) before the test is performed. This allows you to transport blood if necessary, repeat the study in case of errors or technical failures, and place additional samples as initial results are obtained.

TEG has several advantages over traditional coagulation tests. These include working with whole blood (without centrifugation and separation of red blood cells), ease of implementation, assessment of hemostasis at the patient's actual temperature, and the ability to detect excess fibrinolysis. An undeniable advantage of TEG, which is important for working with patients in critical conditions, is the speed of obtaining results. When using the kaolin-tissue factor complex (repid-TEG) ​​test, a diagnostic picture can be available in 3-5 minutes.

The use of special techniques significantly expands the capabilities of TEG. Of these, the heparinase test is the most widely used. Its essence lies in the parallel production of two samples: in a regular cuvette and in a cuvette, the walls of which are treated with heparinase, an enzyme that destroys heparin. Subsequent overlay and comparison of curves demonstrates the contribution of heparin to the patient’s hemostasis, which is important for assessing the effectiveness of anticoagulant therapy and the significance of heparin in the genesis of bleeding, if any. Moreover, TEG with heparinase makes it possible to evaluate the effect of endogenous heparins and their medicinal analogues - heparinoids (for example, sulodexide). It is important to note that standard tests (for example, aPTT) characterize to a greater extent the effect of the drug, and TEG with heparinase characterizes the body's response.

Thank you

The site provides reference information for informational purposes only. Diagnosis and treatment of diseases must be carried out under the supervision of a specialist. All drugs have contraindications. Consultation with a specialist is required!

What is a coagulogram?

However, it is necessary to understand that the coagulation system stops bleeding and ensures the formation of a blood clot not only with skin wounds, but also with any damage to blood vessels. For example, if a vessel bursts due to overstrain or active inflammatory process in any organ or tissue. Also, the coagulation system stops bleeding after separation of the mucous membrane during menstruation or the placenta after childbirth in women.

Disturbances in the functioning of the coagulation system can occur not only by the type of its insufficient activity, but also by its excessive activity. If the coagulation system is insufficiently active, a person develops bleeding, a tendency to bruise, long-term unstoppable bleeding from a small wound on the skin, etc. And with excessive activity of the coagulation system, on the contrary, a large number of blood clots are formed, which clog the blood vessels and can cause heart attacks, strokes, thrombosis, etc.

Returning to the coagulogram, this analysis can be briefly described as a determination of blood coagulation parameters. Based on the results of the coagulogram, it is possible to identify certain disorders in the blood coagulation system and begin their timely treatment, aimed at achieving compensation and preventing bleeding or, conversely, excessive formation of blood clots.

Coagulogram indicators

In addition, there are several varieties of so-called standard coagulograms, which include only some specific parameters necessary for analyzing coagulation in typical situations. Such coagulograms are done under certain conditions, for example, during pregnancy, before surgery, after using medications that affect blood clotting. If any indicators of such standard coagulograms turn out to be abnormal, then to find out at what stage of blood coagulation the disorder occurred, other necessary parameters are determined.

Each coagulogram indicator reflects the course of the first, second or third stage of blood clotting. At the first stage, the blood vessel spasms, that is, it narrows as much as possible, which minimizes the amount of damage. At the second stage, blood platelets “stick together” (aggregate) and form a loose and large clot that seals the hole in the blood vessel. At the third stage, a kind of mesh is formed from threads of the dense fibrin protein, which cover the loose mass of sticky platelets and tightly fix it to the edges of the hole on the vessel wall. Then the mass of sticky platelets compacts and fills the cells between the fibrin fibers, forming a single elastic and very strong “patch” (thrombus), which completely closes the hole in the wall of the blood vessel. This is where blood clotting ends.

Let's consider all the indicators that are part of the coagulogram and reflect all three stages of blood coagulation, and also give examples of standard hemostasiograms for various typical conditions.

So, the coagulogram indicators, reflecting the three different stages of blood coagulation, are the following:

1. First stage indicators formation of prothrombinase):

• Lee-White blood clotting time;
• Contact activation index;
• Plasma recalcification time (PRT);
• Activated recalcification time (AVR);
• Activated partial thromboplastin time (APTT, APTT, ARTT);
• Prothrombin consumption;
• Factor VIII activity;
• Factor IX activity;
• Factor X activity;
• Factor XI activity;
• Factor XII activity.

• Prothrombin time;
• International normalized ratio - INR;
• Prothrombin in % according to Duke;
• Prothrombin index (PTI);
• Factor II activity;
• Factor V activity;
• Factor VII activity.

• Thrombin time;
• Fibrinogen concentration;
• Concentration of soluble fibrin-monomer complexes.

In addition to these indicators, in an analysis called a “coagulogram”, laboratories and doctors often include other indicators that reflect the functioning of another system, which is called anticoagulant (fibrinolytic). Anticoagulant system has the opposite effect of coagulation, that is, it dissolves blood clots and inhibits the blood clotting process. Normally, these systems are in dynamic equilibrium, neutralizing each other’s effects and ensuring blood clotting when needed and dissolution of the clot if it is formed accidentally.

The most typical example of the operation of the anticoagulation system is the following: after damage to the vessel, the coagulation system formed a blood clot, which closed the hole and stopped the flow of blood. Then the wall of the vessel was restored, its tissues grew and completely closed the existing hole, as a result of which the blood clot was simply glued to the already intact wall of the blood vessel. In this condition, a blood clot is not needed; moreover, it has a negative effect, since it narrows the lumen of the vessel and slows down the flow of blood. This means that such a clot must be removed. It is at such moments that the anticoagulant system plays a huge role, since it is activated when unnecessary blood clots are detected and must be removed. As a result of the work of the anticoagulant system, the blood clot is disassembled into parts, which are then removed from the body. That is, the anticoagulant system dismantles blood clots that have already become unnecessary, cleaning the walls of blood vessels and freeing their lumens from a useless cluttering clot that has fulfilled its function.

In addition, it is the anticoagulation system (specifically antithrombin III) that stops the active work of the coagulation system when a blood clot has already been created. That is, when a blood clot closes a hole in the wall of a vessel, the anticoagulation system is activated, which inhibits the activity of the coagulation system so that it, in turn, does not create too large “patches” that can completely block the lumen of the vessel and stop the movement of blood in it.

The work of the fibrinolytic system is assessed by the following indicators which are included in the coagulogram:

• Lupus anticoagulant;
• D-dimers;
• Protein C;
• Protein S;
• Antithrombin III.

Depending on which parameters are included in the analysis, there are currently two main types of coagulograms that are used in everyday clinical practice: extended and screening (standard). The standard coagulogram includes the following indicators:

• Fibrinogen;
• Thrombin time (TV).

The extended coagulogram includes the following indicators:

• Prothrombin in % according to Quick or prothrombin index;
• International normalized ratio (INR);
• Fibrinogen;
• Activated partial thromboplastin time (aPTT);
• Thrombin time (TV);
• Antithrombin III;
• D-dimer.

As a rule, the arrangement of indicators in such coagulograms is arbitrary, depending on what parameters the doctor considers necessary for his work. In many cases, such “standard” and “extended” coagulograms include parameters C-protein, S-protein and others, which need to be determined only in rare cases when a person has coagulation disorders and it is necessary to determine exactly what is not working. In other cases, coagulation tests include indicators such as the ethyl test and clot retraction, which are outdated and not currently used to diagnose the coagulation system. These indicators are included in coagulograms simply because the laboratory performs them.

In fact, such independently compiled “standard” and “extended” coagulograms are very free variations on generally accepted world standards, and therefore are always associated with excessive testing and waste of reagents.

What coagulogram parameters are needed for children and pregnant women?

Coagulogram parameters and their values ​​are normal

Decoding the coagulogram

Lee-White clotting time

Plasma recalcification time (PRT)

Activated recalcification time (ATR)

If AVR or GRP is below normal, this indicates a tendency to thrombosis. If the AVR or GRP is higher than normal, then this indicates the danger of severe bleeding even with minor damage to the integrity of the tissues. Typically, prolongation of AVR or VRP occurs due to a low number of platelets in the blood, administration of heparin, as well as against the background of burns, trauma and shock.

Activated partial thromboplastin time (APTT, APTT, ARTT)

Prolongation of APTT is typical for the following diseases:

• von Willebrand's disease;
• Deficiency of coagulation factors (II, V, VII, VIII, IX, X, XI, XII);
• Congenital deficiency of prekalykrein and kinin;
• Administration of heparin or streptokinase;
• Taking anticoagulants (Warfarin, Sincumarin, etc.);
• Vitamin K deficiency;
• Low levels of fibrinogen in the blood;
• Liver diseases;
• II and III phases of DIC syndrome;
• Condition after a large volume of blood transfusion;
• Presence of lupus anticoagulant in the blood;
• Antiphospholipid syndrome;
• Chronic glomerulonephritis;
• Systemic lupus erythematosus;
• Connective tissue diseases.

• Acute blood loss;
• Initial stage of DIC syndrome.

Activity of all coagulation factors (II, V, VII, VIII, IX, X, XI, XII)

Prothrombin time (PT, RT, recombipl RT)

Thus, prothrombin time reflects a very important physiological phenomenon - the rate of activation of the internal blood coagulation pathway, which is responsible for the formation of blood clots and “patching” holes in the vessels formed due to the negative effects of substances circulating in the blood.

Prolongation of prothrombin time more than normal indicates the following diseases:

• Taking anticoagulants (Warfarin, Thromboass, etc.);
• Administration of heparin;
• Congenital or acquired deficiency of coagulation factors II, V, VII, X;
• Vitamin K deficiency;
• DIC syndrome in the initial phase;
• Hemorrhagic diathesis in newborns;
• Liver diseases;
• Narrowing of the bile ducts;
• Impaired absorption and digestion of fats in the intestines (sprue, celiac disease, diarrhea);
• Zollinger-Ellison syndrome;
• Fibrinogen deficiency in the blood.

• Incorrect blood sampling through the central catheter;
• High or low hematocrit;
• Long-term storage of blood plasma in the refrigerator at + 4 o C;
• Increased concentration of antithrombin III;
• Pregnancy;
• DIC syndrome;
• Activation of the anticoagulant system.

Prothrombin index (PTI)

International normalized ratio (INR)

An increase in INR above normal occurs under the same conditions as an increase in prothrombin time. A decrease in INR below normal occurs under the same conditions as a shortening of prothrombin time.

Prothrombin according to Duke

An increase in the Duke prothrombin percentage above normal occurs under the same conditions as a shortening of prothrombin time. A decrease in the Duke prothrombin percentage below normal occurs under the same conditions as an increase in prothrombin time.

Thus, prothrombin time, prothrombin index, international normalized ratio and Duke prothrombin are parameters that reflect the same physiological effect, namely, the rate of activation of the intrinsic coagulation pathway. These parameters differ from each other only in the way they are expressed and calculated, and therefore are completely interchangeable.

However, it has traditionally developed that in some situations it is customary to assess the rate of activation of the internal pathway of blood coagulation by PTI, in others by INR, and in others by Duke, in fourths by prothrombin time. Moreover, PTI and Duke’s prothrombin in % are almost always mutually exclusive, that is, the laboratory determines either the first or the second parameter. And if the analysis results contain PTI, then prothrombin according to Duke can be omitted and, accordingly, vice versa.

PTI and Duke prothrombin are calculated in diagnostic coagulograms, which people take before operations, during preventive examinations, or examinations for any symptoms. INR is calculated when monitoring and selecting the dosage of anticoagulants (Aspirin, Warfarin, Thrombostop, etc.). Prothrombin time, as a rule, is indicated in coagulograms necessary to identify diseases of the blood coagulation system.

Thrombin time (TV, TT)

An increase in thrombin time reflects a decrease in blood clotting and is observed in the following conditions:

• Fibrinogen deficiency of varying severity;
• DIC syndrome;
• Multiple myeloma;
• Severe liver diseases;
• Uremia (increased concentration of urea in the blood);
• The presence of fibrin or fibrinogen breakdown products in the blood (D-dimers, RFMC).

• Use of heparin;
• The first stage of DIC syndrome.

Fibrinogen concentration (fibrinogen, Fib)

• Myocardial infarction;
• Injuries;
• Burns;
• Nephrotic syndrome;
• Multiple myeloma;
• Inflammatory diseases that last a long time;
• Pregnancy;
• Taking estrogen-containing oral contraceptives (Marvelon, Mercilon, Qlaira, etc.);
• Condition after surgery.

• DIC syndrome;
• Metastasis of malignant tumors;
• Acute promyelocytic leukemia;
• Postpartum complications;
• Hepatocellular failure;
• Infectious mononucleosis ;
• Toxicosis of pregnancy;
• Poisoning by poisons;
• Taking thrombolytic drugs that dissolve blood clots;
• Anchord therapy;
• Congenital fibrinogen deficiency;
• Age less than 6 months.

Soluble fibrin-monomer complexes (SFMC)

Lupus anticoagulant

D-dimers

An increase in the level of D-dimers in the blood develops in the following diseases:

• DIC syndrome (first phase);
• Myocardial infarction;
• Thrombosis of arteries or veins;
• Infectious diseases;
• Acute or chronic inflammatory diseases;
• Gestosis during pregnancy;
• Large hematomas;
• The presence of rheumatoid factor in the blood;
• Condition after surgery;
• Age over 80 years;
• Malignant tumors of any location;
• Use of tissue plasminogen activator.

Protein C

• Congenital protein C deficiency;
• Liver diseases;
• The first stage of development of DIC syndrome.

Antithrombin III

An increase in the concentration of antithrombin III in the blood develops under the following conditions:

• Acute hepatitis;
• Cholestasis;
• Vitamin K deficiency;
• Acute pancreatitis;
• Period of menstruation;
• Taking Warfarin;
• Taking anabolic steroids;
• Long-term or severe inflammatory processes;
• Condition after kidney transplantation;
• Increased levels of bilirubin in the blood (hyperbilirubinemia);
• Taking drugs that increase blood clotting.

• Congenital deficiency of antithrombin III;
• Condition after liver transplant;
• Cirrhosis of the liver;
• Liver failure;
• Deep vein thrombosis;
• DIC syndrome;
• Myocardial infarction;
• Pulmonary embolism;
• Severe inflammatory diseases of any organs and systems;
• Use of heparin in high dosages without monitoring blood clotting indicators;
• The use of L-asparaginase for the treatment of gestosis of pregnancy;
• Third trimester of pregnancy (27 – 40 weeks of gestation inclusive);
• Taking oral contraceptives.

Protein S

Decoding the coagulogram during pregnancy

Due to this increase in the volume of circulating blood, the content of various substances of the coagulation and anticoagulation system increases in a pregnant woman. After all, a woman’s body must provide both itself and the fetus with the substances necessary for the functioning of the coagulation and anticoagulation systems. And that is why during pregnancy there is always an increase in the content of all components of the coagulation and anticoagulation systems, and at the same time an increase in their activity. This, in turn, means that the activity and content of all coagulogram parameters are increased by 15 - 30%, which is the norm for pregnancy.

In practice, this means that the coagulogram norms of a pregnant woman differ significantly from those for other adults. So, normal values ​​of the following parameters during pregnancy are 15–30% less or more than normal:

• Blood clotting time according to Lee-White is 8 - 10 seconds in a silicone tube and 3.5 - 5 seconds in a glass tube;
• Plasma recalcification time – 45 – 90 seconds;
• Activated recalcification time – 35 – 60 seconds;
• Activated partial thromboplastin time is 17 – 21 seconds for Renam reagents and 22 – 36 seconds for “Technology-standard” kits;
• International normalized ratio (INR) – 0.65 – 1.1;
• Prothrombin time – 9 – 12 seconds;
• Prothrombin in % according to Duke – 80 – 150%;
• Prothrombin index – 0.7 – 1.1;
• Thrombin time – 12 – 25 seconds;
• Fibrinogen concentration – 3 – 6 g/l;
• Soluble fibrin-monomer complexes – up to 10 mg/100 ml;
• Lupus anticoagulant – absent;
• D-dimers – first trimester of pregnancy – up to 1.1 mg/l; II trimester of pregnancy – up to 2.1 mg/l; III trimester of pregnancy – up to 2.81 mg/l;
• Protein C – 85 – 170% or 3.1 – 7.1 mg/l;
• Protein S-80 – 165;
• Antithrombin III – 85 – 150%.

However, the analysis indicators do not always fit into the norm, and in this case, women want to understand what this means, that is, to decipher the coagulogram. In general, in order to decipher a coagulogram during pregnancy, you need to know why this analysis is needed and what processes in a woman’s body it reflects. After all, a coagulogram during pregnancy is not done to identify diseases of any organs and systems, but to assess the risk of thrombosis or, on the contrary, bleeding, which can become fatal for the fetus and the woman herself, causing placental abruption or infarction, miscarriages, intrauterine fetal death, gestosis etc.

Therefore, in essence, a coagulogram during pregnancy is prescribed for early detection of the threat of placental abruption, gestosis, antiphospholipid syndrome, latent DIC and thrombosis. The coagulogram does not have any other functions. These pathologies need to be identified at an early stage and the necessary therapy carried out, since in the absence of it they can lead, at best, to loss of pregnancy, and at worst, to the death of the woman herself.

So, if a pregnant woman has a hidden threat of placental abruption, gestosis, DIC or thrombosis, then the coagulogram indicators will vary within the following limits:

• Reduction of antithrombin III to 65% or lower due to excess consumption;
• An increase in the concentration of D-dimers above the norm for pregnancy;
• An increase in the concentration of RFMK by more than 4 times relative to the norm (above 15 mg/l);
• Shortening of thrombin time to less than 11 seconds (first phase of DIC syndrome);
• Prolongation of thrombin time by more than 26 seconds (advanced phase of DIC syndrome, which requires urgent medical intervention);
• Decrease in the amount of fibrinogen below 3 g/l;
• Prolongation of prothrombin time, increase in PTI and INR (initial stage of DIC syndrome);
• Reduction in the amount of prothrombin according to Duke is less than 70% (initial stage of DIC syndrome);
• Prolongation of aPTT more than normal;
• Presence of lupus anticoagulant.