Coagulogram value. APTV in the blood: what is it, causes of low and high, norms in the coagulogram

Coagulogram extended

Coagulogram extended- a set of studies of the blood coagulation system, which, in addition to the basic components (APTT, thrombin time, prothrombin time and prothrombin index, fibrinogen, antithrombin III), includes the determination of lupus anticoagulant, protein C, protein S, D-dimer and RFMK. Coagulation tests are performed in combination with a general analysis. The results of an extended coagulogram are used to diagnose and treat conditions associated with bleeding disorders, monitor anticoagulant therapy, determine the causes of miscarriage, in preparation for surgery and other invasive procedures. Blood sampling is performed from a vein, research methods are coagulometric. Each indicator has its own reference values. Terms of complex analysis - from 1 to 2 days.

An extended coagulogram is a comprehensive blood test that is aimed at assessing various parts of hemostasis: coagulation, anticoagulation and fibrinolytic systems. The results are used to detect hyper- and hypocoagulation, that is, excessive or insufficient blood clotting.

Hemostasis is a combination of blood factors that, on the one hand, maintain it in a liquid state, and on the other hand, promote clotting in case of damage to blood vessels. Normally, the body maintains a balance between anticoagulant and coagulation factors. If it is violated, there is a tendency to thrombosis or bleeding. An extended coagulogram is used to identify the link whose activity is impaired and to further correct the imbalance.

The first group of extended coagulogram tests is aimed at assessing the coagulation link of hemostasis. In the process of blood coagulation, the external and internal pathways are distinguished. The first is triggered by factor III - tissue thromboplastin, which is released from the walls of blood vessels and tissues when their integrity is violated. The internal pathway is activated by the interaction of blood components with the subendothelium of the damaged vessel; factors XII, XI, IX and VII are involved in it. After the formation of factor X, the coagulation pathway becomes common. In an extended coagulogram, tests for prothrombin (PTT, PTI, INR and Quick prothrombin), thrombin time, fibrinogen, APTT are used to study the blood coagulation system. Antithrombin III, lupus anticoagulant, protein C, protein S are tested to evaluate anticoagulant mechanisms. Plasma fibrinolytic activity is examined by tests for RFMK and D-dimer.

When performing an extended coagulogram, the research material is plasma isolated from venous blood. Analyzes are performed by various methods: photometric, colorimetric, immunological, using the orthophenanthroline test. Automatic and semi-automatic coagulometers are used. An extended coagulogram is widely used in hematology, obstetrics and gynecology, surgery, resuscitation, cardiology, phlebology and other areas of clinical practice.

Indications and contraindications

An extended coagulogram is used for a general assessment of hemostasis, diagnosis and monitoring of diseases accompanied by a violation of the external, internal and final pathway of blood coagulation, the activity of the anticoagulant and fibrinolytic system. The study is indicated for DIC, venous thrombosis, thromboembolism, hemophilia, antiphospholipid syndrome. Also, the analysis is carried out to evaluate the effectiveness of anticoagulant therapy and identify associated complications. The basis for the appointment of an extended coagulogram may be frequent nosebleeds, bleeding gums, blood in the stool and urine, hemorrhages under the skin and in the joints, anemia, heavy menstruation, pain and heaviness in the legs, the appearance of vascular "mesh" and "stars". The reason for performing an extended study may be the deviation of the indicators of the tests of the basic hemostasiogram.

In obstetrics and gynecology, an extended coagulogram is indicated for women who have a history of bleeding disorders, recurrent miscarriage, as well as pregnancy complications: threatened miscarriage, placental abruption, fetal hypoxia. At the stage of pregnancy planning, this study is used to diagnose the causes of infertility. In surgical practice, an extended coagulogram is carried out as part of the preoperative preparation of the patient, the identification of complications in the postoperative period. Screening of the blood coagulation system is indicated for hereditary predisposition to thrombosis and hemophilia.

Most extended coagulogram tests are not indicated for inflammatory, including infectious and autoimmune diseases, since in these cases blood clotting temporarily changes, and the indicators become uninformative. The study itself has no contraindications, but blood sampling is impossible if the patient is psychomotor agitated, has severe anemia or hypotension, and frequent convulsions. An extended coagulogram allows you to most fully assess the hemostasis system and accurately determine which links in it are broken. But for the correct diagnosis, the interpretation of the results should not be carried out in isolation, but in combination with indicators. general analysis blood with ESR and leukocyte formula, as well as data from clinical and instrumental examinations.

Preparation for analysis and collection of material

To determine the parameters of the extended coagulogram, blood plasma is used. Her collection is usually made from 8 to 11 am. The break between the procedure and the last meal should be at least 8-12 hours. Since stress, exercise and smoking affect blood clotting, these factors should be eliminated at least half an hour before sampling. If possible, all medications should be stopped in advance or the effect of taking them on the results of the analysis should be discussed with the doctor.

Blood for research is taken from a vein. It is collected in a test tube with sodium citrate and gently mixed - this prevents the formation of clots. Over the next 2-6 hours, the material is delivered to the laboratory, centrifuged to obtain plasma, into which the reagents specific for each test are then injected. Part of the samples is incubated and then applied to the substrate or combined with another reagent. The procedure and calculation of indicators are performed automatically in special analyzers - coagulometers. The timing of the study depends on the set of tests, most often they are 1-2 days, but can take up to 7-14 days (for example, when determining proteins C and S).

Normal values

In adult patients, the following values of extended coagulogram tests are normally determined:

Prothrombin test: prothrombin time (PTT) - 11-15 sec.; prothrombin index (PTI) - 95-105%; international normalized ratio (INR) - 0.8-1.2; prothrombin according to Quick - 78-142%;
thrombin time - 16-21 sec.;
fibrinogen - 2-4 g / l;
APTT - 21-36.5 sec.;
Anticoagulant system: antithrombin III - 66-124%; lupus anticoagulant - 0.8-1.2; protein C - 70-140%; protein S for women - 54.7-123.7%, for men - 74.1-146.1%;
Plasma fibrinolytic activity: RFMK - 3.36-4.0 mg / 100 ml; D-dimer - 0-0.55 µg FEU / ml.

However, the corridor of reference values may differ from laboratory to laboratory, as they use different reagents, analyzers, and sometimes research methods in general. Therefore, it is necessary to determine the norm according to the form with the results (column "reference values"). In addition, blood clotting changes during pregnancy and menopause, during the period of intensive growth and puberty, when smoking, using certain drugs. Temporary physiological deviations in the parameters of the coagulogram are observed during physical exertion, emotional stress.

Diagnostic value of the analysis

In diseases and conditions accompanied by an increase in blood clotting and the risk of thrombosis, the parameters of the extended coagulogram change as follows: INR, PTT, fibrinogen and / or D-dimer exceed the norm, lupus anticoagulant is detected, and PTI, Quick prothrombin, thrombin time, antithrombin III , APTT, protein C, protein S - decrease. Deviations can be detected in one or more tests, depending on which link of hemostasis is broken. In such cases, thrombosis, thromboembolism, stages 1 and 2 of DIC are diagnosed. Also, such changes are typical for the last trimester of pregnancy, the period after injuries, burns, operations.

When blood clotting is insufficient (hypocoagulation), there is a risk of bleeding. In this case, the parameters of the extended coagulogram change as follows: the values of PTI, Quick prothrombin, thrombin time, antithrombin III, APTT, protein C, protein S increase. Lupus anticoagulant is absent, and the values of INR, PTT, fibrinogen and D-dimer decrease. As in the previous case, the deviation can be detected in one or more analyzes. Hypocoagulation is determined by congenital or acquired deficiency of coagulation factors, including hemophilia, von Willebrand factor deficiency, hypo- and afibrinogenemia, vitamin K deficiency, stages 2 and 3 of DIC.

Treatment of deviations from the norm

An extended coagulogram allows you to comprehensively explore the hemostasis system, identify deviations in various parts of the coagulation, anticoagulation and fibrinolytic systems. Its results are most in demand in hematology, surgery, obstetrics and gynecology. If deviations from the norm are detected, it is necessary to seek advice and treatment from the doctor who issued the referral for analysis. If blood clotting is increased or decreased slightly, then you can correct it yourself. To do this, you need to avoid stressful situations, select physical activity in accordance with the level of preparedness of the body, refuse uncontrolled intake drugs and smoking, timely detect and treat inflammatory diseases.

Our organism protect numerous mechanisms that ensure homeostasis - the constant constancy of the internal environment of our body. One of the most important of them is the system of hemostasis or coagulation, which prevents blood loss when the integrity of the bloodstream is damaged. In the process of blood clotting and thrombus formation, there are dozens of reactions that can be influenced by hundreds of different chemical substances. And in itself, this system includes a number of other regulatory mechanisms, some of which increase blood clotting, while others lower it.

Due to the great importance of the system hemostasis for the stable functioning of the body, in clinical medicine developed various methods study of this protective reaction of the body. The most common analysis for the study of blood clotting is the determination of the coagulogram, which includes determining the time required to stop bleeding and the number of various factors of this system. This study gives a lot of information about the state of the body as a whole, because the normal operation of the hemostasis system depends on the proper functioning of various organs and systems, so any disturbances in their work are reflected in the coagulogram.

There are a number testimony that warrant this study. Firstly, the determination is mandatory before surgical interventions - during operations, the integrity of the bloodstream is significantly violated, which must be eliminated by the hemostasis system. Otherwise, serious complications may develop in postoperative period. Secondly, this analysis is often prescribed to pregnant women - due to strong hormonal changes various disorders of blood clotting are possible, both in the direction of its decrease and increase. Thirdly, the determination of a coagulogram is desirable for diseases of various organs that are somehow related to the process of blood coagulation - first of all, these are the liver, spleen, bone marrow, the cardiovascular system. Also, autoimmune diseases have their influence on the formation of blood clots. Finally, determining the activity of the blood coagulation system is useful and, in some cases, necessary before prescribing certain medicines- anticoagulants (for example, heparin), acetylsalicylic acid, hormonal contraceptives.

Donating blood for determination activity of the coagulation system requires some preparation. 8-12 hours before the study, you should not take food, alcoholic beverages, coffee or strong tea. Some of the parameters of the coagulogram have a certain instability, especially under stressful conditions for the body, therefore, before and during the test, one should not be nervous, undergo severe physical activity. Immediately before blood sampling, a person is given a glass to drink. pure water- this increases the accuracy of the study. Blood is taken from a vein in the arm and immediately begin to determine the main indicators.

Exists basic and detailed blood test to determine the coagulogram. The norm of the basic coagulogram looks something like this:

Despite such a large number indicators, usually the form of the basic coagulogram contains only the main ones - fibrinogen concentration, clotting time, activated recalcification time (AVR), activated partial thromboplastin time (APTT), prothrombin index, thrombin time, the amount of soluble fibrin-monomeric complexes. Based on these values, one can indirectly determine the activity of a particular factor.

clotting time- one of the basic indicators, which is determined by one of the first. Its value depends on the type of material of the test tube in which the indicator is determined. In a glass container, the formation of a blood clot normally takes from 5 to 7 minutes, while in a silicone tube, the normal clotting time is 12-25 minutes. Due to such a large difference between the two norms of this indicator, depending on the material of the container, it is necessary to specify in the analysis form whether a silicone or non-silicone tube was used for this. The lengthening of this indicator indicates a decrease in the activity of the hemostasis system or an increase in the thrombolytic ability of the blood, and a more rapid formation of a blood clot indicates the opposite phenomenon - an increase in the activity of blood coagulation, or a decrease in the antithrombin system. The causes of these phenomena are determined by other indicators of the coagulogram.

fibrinogen concentration- one of the main proteins of the hemostasis system - is also a key indicator of the coagulogram. It is this soluble protein that, during the formation of a blood clot, turns into strands of insoluble fibrin, which forms a thrombus. The norm of its content is 2-4 g / l of blood plasma, which is a fairly high indicator. It is characteristic that in pregnant women on the eve of childbirth (in the third trimester), there is an increase in the content of fibrinogen up to 6 g / l, which is a normal preparation of the body for bleeding that accompanies the birth of a child. However, you should carefully monitor this indicator - its excessive increase can cause blood clotting right inside the bloodstream, which underlies the onset of DIC, often leading to death. In addition to pregnancy, fibrinogen levels increase with various inflammatory processes, shocks of various origins, endocrine disorders.

Decrease in this indicator coagulograms causes increased bleeding and an increase in blood clotting time. The cause of this condition may be some liver diseases (hepatitis, cirrhosis), lack of vitamins (K, C, B) and related diseases of the gastrointestinal tract (dysbacteriosis, Crohn's disease, malabsorption syndrome), taking certain drugs, as well as the second stage of DIC.

Activated time recalcification (AR) in a coagulogram, it characterizes how quickly the level of calcium ions (which are involved in the formation of a blood clot) in the blood plasma is restored. The normal phenomenon is the value of this indicator in the range from 1 to 2 minutes (60-120 seconds). An increase in the duration of recalcification indicates a reduced blood coagulation activity, which is a consequence of an insufficient number of platelets in the blood or their functional inferiority, a lack of the main factors of the hemostasis system, an increased activity of the antithrombin system, and also in the second stage of DIC, when there is an exhaustion of the entire blood coagulation system .
Decreasing time recalcification speaks of increased thrombosis - with thrombophlebitis and thrombosis.

Activated partial thromboplastin time (APTT)- characterizes the time it takes for the formation of a blood clot. The norm of this parameter of the coagulogram is 35-45 seconds, but when using some types of reagents, 28-35 seconds can also be considered the norm. The shortening of this time is not typical clinical sign any disorders, but a significant increase occurs with the use of anticoagulants (heparin), an acquired or congenital deficiency of the main blood coagulation factors (for example, hemophilia), with some autoimmune diseases (systemic lupus erythematosus).

Prothrombin index- the ratio of human plasma time to the reference value. This indicator of the coagulogram is expressed as a percentage and is normally 78-142%. The prothrombin index is the most accurate value that determines the efficiency of the entire hemostasis system. decline this indicator is a sign of low blood clotting, which occurs as a result of a lack of basic factors, vitamin K deficiency, diseases of the liver and gastrointestinal tract. An increase in the protombin index indicates a high risk of thrombosis and related disorders - myocardial infarction, stroke, kidney damage, thromboembolism of various vessels.

thrombin time- an indicator closely related to the level of fibrinogen in the blood. Physically, it represents the time during which a certain amount of fibrinogen passes into insoluble fibrin - the norm is from 10 to 20 seconds. With an increase in this time, a decrease in the level of fibrinogen is observed, or this phenomenon is due to the activity of fibrinolytic systems and factors - for example, in liver diseases, pancreatitis. Also, an increase in thrombin time occurs with the use of anticoagulants. A decrease in this indicator of the coagulogram is observed in the last trimester of pregnancy and other factors leading to an increase in the level of fibrinogen in the blood.

The amount of soluble fibrin-monomeric complexes- these proteins are a transitional link between fibrinogen and fibrin. The norm of their content in blood plasma is 3.36-4.0 mg per 100 ml of plasma. An increase in the number of these complexes indicates an increased activity of the hemostasis system. A decrease in this indicator is observed with a general decrease in the activity of the blood coagulation system. This indicator is the first to respond to the use of anticoagulants, therefore it is the most accurate and sensitive method for determining the effectiveness of anticoagulant therapy, which is widely used in clinical practice.

Typically, after analysis an extended study is performed to compile a basic coagulogram, which is used to confirm problems with blood clotting. The purpose of obtaining an extended coagulogram is more precise definition causes of certain bleeding disorders. As part of the extended analysis, a number of additional indicators are determined.

Protein C is one of the most important anticoagulant factors. Its level is expressed as a percentage of the reference indicator, the norm of determination in the extended coagulogram is 60-140%. With a decrease in this indicator, the blood coagulation system begins to prevail, which leads to increased thrombosis. The reason for the decrease may be liver disease and vitamin K deficiency, which often develops as a result of colon dysbacteriosis. Also, a decrease in the level of protein C may be due to genetic factors.

D-dimer is a product of partial disintegration of a fibrin clot (thrombus), therefore, with increased thrombus formation, the level of this indicator also increases. The content norm - its amount should not exceed 500 ng / l. In pregnant women in the last trimester, due to a general increase in the activity of the hemostasis system, the level of D-dimers may slightly exceed the norm. In other cases, a significant increase in this indicator is a symptom of thrombophlebitis, disorders in decompensated diabetes, with toxicosis.

Antithrombin-3, as well as protein C, is an anticoagulant factor, the norm of which is from 75 to 110% of the reference value. A sharp decrease in the content of this factor plays a special role, since in such a situation the risk of thrombosis with the development of an embolism or even DIC increases significantly.

Antibodies to phospholipids also called lupus antibodies, are normally completely absent in the blood. Their appearance in plasma is a sign of systemic lupus erythematosus, a severe autoimmune disease. The determination of their content in plasma within the framework of an extended coagulogram is due to the fact that this type of antibody destroys platelets and thereby sharply reduces blood clotting.

Level platelets when determining the coagulogram, it is rarely determined, since often this value is already known from the general blood test. However, the role of platelets, the norm of which is 180-320 billion per liter, in the development of a blood clot is enormous, so it makes no sense to start any research without first determining their number.

Educational video of decoding the coagulogram in normal and abnormal conditions

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A hemostasiogram (coagulogram) is a blood test performed to determine the level of its coagulation. Deciphering the hemostasiogram of blood has great importance while preparing the patient for surgery. It helps prevent such possible complications like bleeding and thrombosis. The study of coagulation is certainly carried out during the passage of pregnancy, and if there is a history of diseases of the vessels, heart and liver. The presence of autoimmune diseases is also an indication for a blood hemostasiogram. The analysis makes it possible to determine the cause of bleeding.

General information

The hemostasis system (blood clotting) protects the patient from dangerous blood loss during violation of the integrity of the walls of blood vessels against the background of surgical interventions and traumatic injuries. For normal hemostasis, the body is responsible for the endocrine and nervous system. In order for the blood to adequately perform its main functions (regulation of body temperature, supply of tissues with nutrients and oxygen), it must have normal rheological properties, that is, fluidity.

Reduced coagulation (hypocoagulation) against the background of various pathologies can lead to blood loss, which is life-threatening. This condition is the cause of the appearance of blood clots (blood clots) that close the lumen of the vessels. As a result of thrombosis, tissue ischemia is formed, which leads, among other things, to strokes and heart attacks.

The main elements of the hemostasis system:

plasma factors;
platelets;
endothelial tissue of the vascular wall.

Blood is collected from a vein in the area of the elbow bend. In order to prevent misinterpretation and distortion of the results, it is necessary to prepare for the examination carefully.

If a person takes pharmacological anticoagulant drugs, then he must tell the doctor about it. If during the blood sampling for examination of the coagulogram, a fainting state begins to appear or dizziness develops, then it is necessary to immediately notify the doctor.

Indications and method of analysis

Indications for a coagulogram are as follows:

previous strokes and heart attacks;
high tendency to thrombosis;
liver disease;
vascular diseases;
preparation for surgery;
pregnancy.

Blood is taken with a syringe or using a vacuum system. The tourniquet is not applied to the hand. The puncture must be atraumatic in order to prevent data distortion due to the ingress of a significant amount of tissue thromboplastin into the collected material. Two test tubes are filled with blood, but only the second is used to perform the analysis. In a sterile test tube is an anticoagulant - sodium citrate.

Norms and interpretation of the coagulogram

During a standard analysis for a coagulogram, a large number of indicators are determined, which are evaluated in aggregate.

The prothrombin index (PTI) reflects the ratio of the duration of blood clotting in the norm to the duration of clotting in a patient. Variants of the norm (reference values) - 96−100%. In pregnant women, this figure is increased (up to 120% or more), this is not a pathology. PTI indicators make it possible to determine the absence or presence of liver diseases. The index increases on the background of use hormonal contraceptives. An increase in indicators relative to the norm indicates the risk of thrombosis, and a decrease indicates a possible bleeding.

In order for the prothrombin index to be normal, the body needs a regular intake of vitamin K.

Clotting time is the time interval between the onset of bleeding and its completion with the formation of a fibrin clot. Venous blood coagulates in 7-12, and capillary blood in 0.7-4 minutes. The duration of bleeding increases against the background of hypovitaminosis C, thrombocytopenia, taking drugs from the group of indirect anticoagulants (including Warfarin, Trental and acetylsalicylic acid), liver diseases and hemophilia. The duration of clotting is reduced after heavy bleeding, and in women - and against the background of the use of oral contraceptives.

Activated partial thromboplastin time (APTT) is a value that reflects the duration of clot formation after addition of calcium chloride (CaCl2) to plasma. Normal readings are approximately 35-45 seconds. Changes occur during the deviation of other indicators of the coagulogram in the range of 35%. The lengthening of this time interval may indicate hypovitaminosis K or liver disease.

Thrombin time measures the rate at which fibrinogen is converted to fibrin. The norm is 14-19 seconds. A decrease in this period of time with a high degree of probability indicates an excess of fibrinogen, and its increase indicates a functional severe liver failure in cirrhosis, against the background of hepatitis, or an insufficient concentration of this protein compound in the serum.

Constant monitoring of this coagulogram value is very important during heparin treatment.

Plasma recalcification time (PRT) is the value of the coagulogram, which correlates with AVR and reflects the time interval of coagulation of citrate serum with calcium salt preparations. The norm is 1.5-2 minutes. Reducing the time indicates a high activity of hemostasis.

Activated recalcification time (ART) in healthy people is approximately 40-60 seconds. This value helps to determine the passage of one of the stages of coagulation. A decrease in ABP is a symptom of thrombophilia, and an increase is noted with the use of anticoagulants (heparin), thrombocytopenia, development state of shock, extensive burns and serious injuries. A lower AVR value indicates an increased risk of massive bleeding.

At healthy person the amount of fibrinogen is 6−12 µmol/l. Its decrease occurs during liver problems, and its increase occurs during hypofunction thyroid gland and malignant neoplasms.

The amount of fibrinogen during the absence of diseases is in the range of 2.5–4.5 g/l. This protein compound is formed in the liver, and is transformed under the influence of coagulation factors into fibrin, its threads are the main structure of blood clots.

If the coagulogram shows a significant decrease in value, this may be a symptom of such pathologies:

severe liver disease;
violation of hemostasis;
lack of ascorbic acid and hypovitaminosis of group B;
toxicosis during pregnancy.

The level decreases with the use fish oil, as well as in the treatment of anabolics and anticoagulants.

An increase in the amount of fibrinogen is observed with significant burns, hypothyroidism, acute infections, acute disorders blood circulation (heart attacks and strokes), against the background of hormone therapy, postoperative interventions, and in women - during pregnancy. Normally, Fibrinogen B is not detected.

Fibrinolytic activity is the value of the coagulogram, which reflects the ability of human blood to dissolve blood clots that have appeared. The component of the anticoagulant system, fibrinolysin, is responsible for this function in the body. During its increased concentration, the time for the dissolution of blood clots increases, thus, bleeding increases.

Soluble fibrin-monomeric complexes (SFMK) show a change at the molecular level in the protein structure of fibrin under the influence of plasmin and thrombin. Normal is an indicator that does not exceed 5 mg / 100 ml. The variability of this value is explained by the same reasons as the change in the amount of fibrinogen.

RFMK is a marker, which makes it possible to take timely measures to prevent the occurrence of DIC.

Plasma tolerance to heparin. The norm is - 8-17 minutes. The analysis makes it possible to determine the amount of thrombin in the blood. A decrease in the value with a high degree of probability indicates liver diseases. If the time interval is less than 8 minutes, then you can suspect the presence malignant neoplasms or cardiovascular disease. Hypercoagulability is often noted on the state of postoperative interventions and on later dates pregnancy (third trimester).

Thrombotest makes it possible to visually determine the amount of fibrinogen in the examined material. In the normal state, this is a stage 3-5 thrombotest.

Duke bleeding time- this is a separate analysis, during which capillary blood is examined, and not venous. The pad on the finger is pierced 5 mm deep with a lancet. The blood that has come out from the puncture is removed with a special piece of paper every 20-35 seconds (without touching skin). After each removal, the time until the next drop appears. The time of completion of bleeding from the vessels in a healthy person is 1.5-2 minutes. This indicator, in particular, is affected by the content of the mediator serotonin.

Retraction of a blood clot is expressed by a decrease in its quantity and complete separation from the plasma. Normal- 44−60%. An increase in the index is observed at different forms anemia, and the decrease is the result of erythrocytosis.

Features of the coagulogram in children

In children, the indicators of the norm of the coagulogram are very different from the norm in adults. Thus, in newborns, the normal amount of fibrinogen is 1.3-3.5 g / l.

Indications for a coagulogram in children:

upcoming surgery;
diagnosis of diseases of the hematopoietic system;
suspected hemophilia.

Coagulogram during pregnancy

During pregnancy coagulogram produced at least three times (in each trimester).

During pregnancy, hemostasis parameters normally change, this is caused by hormonal changes in the woman's body, the appearance of the uteroplacental circle and an increase in the total amount of circulating blood.

In the first trimester, the clotting rate increases significantly, and in the third it greatly decreases, thus providing the woman with protection from possible blood loss during delivery. The coagulogram makes it possible to determine the threat of premature birth or spontaneous abortion as a result of the formation of blood clots. Disorders in the coagulation system of a pregnant woman adversely affect the central nervous system of the unborn baby.

Mandatory analysis of the coagulogram is required if a woman has vascular disease or liver failure is determined. The coagulogram is also examined with a negative Rh factor and a decrease in immunity.

Normal indicators of individual coagulation values in pregnant women:

APTT - 18−22 seconds.
thrombin time - 12−19 seconds;
prothrombin - 80−140%;
fibrinogen - 7 g/l.

Deviation in the amount of prothrombin from the norm can talk about placental abruption.

Blood coagulation is a reliable defense mechanism of our circulatory system. A large number of diseases and pathologies of various organs can affect its work. Therefore, monitoring the normal functioning of hemostasis by determining the coagulogram is a reliable way to diagnose many diseases and prevent possible complications.

Blood is a mirror of the state of the human body. The laboratory assistant can see everything in the blood: what a person ate, what he drank, whether he used any medications. There are many tests available to be performed in the laboratory. Coagulogram (hemostasiogram) is the result. With it, you can determine the increased coagulability of the blood or reduced. The coagulogamma test is not prescribed as a standard, it is used to clarify the diagnosis, subject to the availability of appropriate indications. And so let's consider what kind of analysis a coagulogram is, how to decipher it in an adult, during pregnancy and in children.

In the process of stopping the blood, an interaction of clotting factors occurs. These are specific body proteins that are normally found in the blood. Factors are released from the damaged intima of the vessel, triggering a cascade of reactions during which the proteins sequentially activate each other. As a result: fibrinogen turns into fibrin, which is insoluble in plasma, and falls out in filaments. In them, as in a web, cells of red, white blood and platelets get stuck. The formed thrombus of the vessel stops the bleeding.

Hemostasis system

After the restoration of the integrity of the intima of the vessel, the process of fibrinolysis starts. There is no longer a need for a thrombus, and its separation will contribute to blockage of some small vessel and rupture of the latter.

To maintain balance, an anti-coagulant system works in opposition to the blood coagulation system. Thanks to it, blood clots do not constantly form in the body, the blood maintains its liquid state. The two systems balance each other. Because of this balance, blood constantly runs through the vessels, but at the same time, when injured, a person does not die from massive blood loss. Violation in the system contributes to either profuse bleeding during injuries or blood clotting in the vascular bed.

According to the indicators of the analysis of the blood coagulogram, it is possible to evaluate the work of the coagulation, anticoagulation systems and the fibrinolysis system. Deciphering the blood coagulogram and its interpretation is available only to a qualified attending physician.

Indications

Indications for a coagulogram study:

assessment of the work of the hemostasis system, fibrinolysis and anticoagulant system;
upcoming surgery;
congenital diseases of the coagulation system;
childbirth and C-section(also peculiar operations, accompanied by blood loss);
treatment with anticoagulants;
to assess the tendency to thrombosis with;
varicose veins;
chronic liver diseases;
taking glucocorticosteroids, anabolic steroids, oral contraceptives;
auxiliary diagnostics of autoimmune diseases (antiphospholipid syndrome with).

Training

Analysis of the coagulogram is not taken in the morning on an empty stomach. On the eve of 10-12 hours should be excluded from the diet of fried, spicy, fatty foods, you can not drink alcohol. Immediately before a blood test for a coagulogram, you can drink water, do not smoke. Stop taking everyone medicines(including antibiotics for 1-2 weeks), hormonal contraceptives. If these measures are not followed, you can get a distorted result.

For a coagulogram, it is carried out using a special or ordinary syringe with a needle with a large clearance, without applying a tourniquet. It is important that the procedure is minimally traumatic for the vascular wall. The tube contains an anticoagulant to prevent blood clotting in vitro. The results of the analysis of the coagulogram are prepared for several days.

Decryption

The blood coagulogram evaluates the main and additional parameters. The norm of the coagulogram changes in such a physiological state as pregnancy. Consider the norms and interpretation of the blood coagulogram in the table.

The main parameters for deciphering a blood coagulogram in an adult include:

clotting time. The value depends on the material of the tube in which the analysis was performed. In a non-silicone tube, the normal value is 5-7 minutes, in a silicone tube - 20-25 minutes. The analysis form will specify which tube was used during the analysis so that the doctor can evaluate the result.
fibrinogen. It is on the concentration of this protein that the effectiveness of hemostasis depends, since fibrin, the main component of a thrombus, is formed from it. In pregnant women, it increases before childbirth. The body thus prepares for the programmed upcoming bleeding.

The level of fibrinogen in the blood increases in addition to the above example:

at acute inflammation and infections;
at acute pathologies heart or blood vessels;
with diseases of the respiratory system;
with extensive burns;
after surgical operations;
with endocrine disorders;
after childbirth or caesarean section.

It is very important to monitor the content of fibrin in the blood, because its uncontrolled increase will lead to a dangerous condition in which the blood will begin to clot in intact vessels. It's called DIC and can be fatal.

A decrease in the level of fibrinogen in the blood occurs in such cases:

with liver diseases;
taking anticoagulants, steroids;
toxicoses;
deficiency of B vitamins;
vitamin C deficiency.

Activated partial thromboplastin time (APTT). This value reflects the time required for fibrin formation. Normal APTT values are 35-45 s, when using certain reagents - 28-35 s. The shortening of this time has no diagnostic value. A prolongation of the APTT indicates congenital disorders of the coagulation system or that the patient has taken anticoagulants the day before.
Prothrombin index (PTI), international normalized ratio (INR). A parameter by which the extrinsic fold path can be evaluated. Equal to the time elapsed from damage to the vessel to the formation of a clot. The index can be calculated as the ratio of the reference time of a healthy person and the time of this patient. The most universal indicator is the INR. Normal PTI values are 78-142%.
thrombin time. The parameter characterizes the time during which fibrinogen is converted to fibrin. The normal figure is 10-20 seconds.

An increase in value is observed in the decoding of the analysis when:

liver diseases;
pancreatitis;
oncological diseases;
taking anticoagulants;

Decrease in fibrinogen:

the last trimester of pregnancy and other conditions that increase the amount of fibrinogen in the blood.

As you can see, the coagulogram during pregnancy differs from normal. Only the attending physician can decipher the analysis of the coagulogram of blood.

Additional indicators of the coagulogram include:

Antithrombin III. Determination of antithrombin in the blood will help evaluate the work of the anticoagulant system of the blood.

An increase in the level of the coagulogram is observed when:

severe infectious diseases;
the presence of acute hepatitis;
in the presence of acute pancreatitis;
treatment with anticoagulants and steroids.

Level down:

congenital and hereditary deficiency of factors;
pathology of the heart;
last trimester of pregnancy;
DIC syndrome.

Soluble fibrin-monomeric complexes. The indicator gives an idea of the changes in the fibrin molecule under the influence of precursor factors.
Protein C. One of the most important anticoagulant factors. The norm in an extended study is 60-140%.
Fibrinogen B - normally absent;
. Or antibodies to phospholipids. Normally absent in the blood. This type of autoantibody causes the destruction of platelets and thereby reduces the ability of the blood to clot;
D-dimer is a breakdown product of fibrin. The concentration in the blood is proportional to the lysis of this protein. With increased thrombosis, the indicator rises.
Heparin tolerance. The patient is given heparin. Then the blood is taken and the time of formation of the blood clot is determined. Normal value 7-15 minutes.

This value increases when:

oncological diseases;
pregnancy;
after surgical intervention;
with liver diseases (cirrhosis,).

Duke bleeding time. A finger is punctured and the researcher removes a drop of blood every 15 seconds without touching the skin, until the bleeding stops. Normal value 2 minutes
Recalcification time. An indicator showing the formation of a fibrin clot. Activated recalcification time. The normal value is 50-70 seconds.
fibrinolytic activity.
clotting time. It is noted from the time of blood sampling to the time when blood clot. To determine the test tube is placed in a thermostat, set to 37 degrees. Normal values are 5-7 minutes (if venous blood was taken).

Increase value:

hypercoagulation;
DIC;
taking hormonal contraceptives.

Retraction of a blood clot. Reflects the ability of the fibrin threads of the formed clot to contract. A decrease in the indicator occurs with an increase in the number of erythrocytes. Decrease - with developing anemia.
. Platelets play a key role in hemostasis. When analyzing for a coagulogram, this indicator is rarely determined. The analysis for platelets is given together with the UAC.
Thrombotest. Reflects the intensity of fibrin clot formation. I-III degree - a clot is formed loose and fragile. I-III degrees are characterized by the formation of an inferior loose free-floating clot. Grade IV, a formed clot is glued to the wall of the test tube. VII degree - the clot can be separated from the wall only with a wire loop, elastic and very compacted.

"Coagulogram - what is it?" - ask in surprise the patients who are sent to take such an analysis. Indeed, ordinary people rarely encounter such a study, usually in preparation for a planned operation. This term is familiar to all pregnant women. An analysis of the coagulogram in the process of bearing a child is done every trimester.

Research is hidden under an incomprehensible word. The set of indicators studied may vary depending on a particular laboratory. The analysis is indicative and detailed. In the first case, it is only determined in which direct link in the coagulation process the violation occurred. An expanded coagulogram is a type of study that, in addition to qualitative, also studies quantitative defects. With its help, it is possible to identify platelet disorders, various thrombophlebia, deficiency of certain clotting factors, etc.

The set of methods used to obtain the result depends on clinical picture, type of pathology, goals of analysis. It should be noted that deciphering a blood coagulogram is a great difficulty not only for a non-specialist, but sometimes for a doctor. Usually, in order to make an accurate diagnosis, several well-chosen tests are required.

blood clotting process

Let's take a closer look at how the coagulation system functions. At the first stage, with chemical or mechanical damage to the walls of blood vessels, thromboplastin is released - a special substance that triggers coagulation reactions. Then there is an activation of coagulation factors - special proteins that are always normally present in the blood and provide the formation of a blood clot at the site of damage to the vessel wall.

Further, thrombin (a natural component of the coagulation system formed from prothrombin) activates the inactive fibrinogen protein, turns it into active fibrin, which forms the basis of the clot. Blood elements, including platelets, "get entangled" in fibrin networks. As a result, the platelets contract and compress the clot, forming a mature thrombus that closes the damage to the vascular wall. In contrast to the blood coagulation system, the body also has an anti-coagulation system. Together they allow the blood to be maintained in a normal state.

Coagulation study in pregnant women

As already noted, every trimester, and in some cases more often, a coagulogram is taken by pregnant women. What it is and why it is needed, expectant mothers know firsthand. The fact is that during the bearing of the baby, the activity of the coagulation system as a whole increases. it natural process associated with the fact that the uteroplacental circle of blood circulation appears. The body of the expectant mother thus prepares for possible blood loss during childbirth.

To identify the features of blood clotting disorders and some complications of pregnancy, a coagulogram is performed. The doctor may ask for an analysis at an unscheduled time if there are deviations from the norm of hemostasis parameters (components of blood and blood vessels, the interaction of which allows maintaining the integrity vascular walls and stop bleeding if damaged). Blood for research is taken in the morning on an empty stomach from a vein.

Deciphering the coagulogram of blood

Only a specialist should study the results of the analysis. Without special knowledge, a person will not be able to decipher the coagulogram indicators and assess the degree of their deviation from the normative values. We will try to understand the intricacies of the process and talk about the main parameters of the study.

1. Fibrinogen

This is a protein synthesized in the liver, which is converted under the influence of a certain blood factor into fibrin. This indicator necessarily includes fibrinogen - 2-4 g / l. If it is increased, then clotting is increased, and there is a risk of blood clots. Typically, this situation occurs before childbirth, with pneumonia, after surgery, with infections and inflammations of an acute nature (tuberculosis, influenza), myocardial infarction and stroke (on the first day), with burns, hypothyroidism, taking oral contraceptives and estrogens. may be due to toxicosis, cirrhosis of the liver or severe hepatitis, lack of vitamin B12 or C, androgen, anabolic steroids, fish oil, anticoagulants.

2. Activated partial thromboplastin time (APTT)

A coagulogram examines the time during which, after calcium chloride and other substances combine with plasma, a blood clot forms. If at least one clotting factor is below the norm by 30-40 percent, the APTT level will change. On average, the norm is 30-40 seconds. The time may increase with a lack of vitamin K, liver disease. The reason for the increase in the duration of APTT and, as a result, the slowing of coagulation may be hemophilia.

3. Lupus anticoagulant

This parameter always contains a coagulogram. What is this indicator? Now we'll tell you. These are IgC and IgM antibodies, leading to an increase in APTT. Normally, they should not be produced in pregnant women. Antibodies appear in the case of autoimmune diseases, with preeclampsia. Pregnancy against the background of such a pathology often ends in spontaneous abortion, fetal death or placental infarction.

4. Prothrombin

It is a complex protein that is a precursor of thrombin (a protein that stimulates the formation of blood clots). This is one of the most important indicators of the coagulogram. Prothrombin with the participation of vitamin K is synthesized in the liver. After analyzing the value of this parameter, the doctor can identify pathologies of the gastrointestinal tract and liver.

5. Prothrombin time

The time during which a fibrin clot is formed in plasma when thromboplastin and calcium chloride are added to it. This indicator is expressed in seconds and is normally equal to 11-15.

6. Prothrombin index (PTI)

The coagulogram most often includes this parameter, instead of the previous one. This is the ratio of the clotting time of the plasma of a healthy person and the plasma of a patient, expressed as a percentage. B should fluctuate between 93-107 percent. The factors of this indicator are synthesized in the liver cells; in liver diseases, their number decreases, so PTI can to some extent serve as a parameter for determining the functional state of the organ.

If PTI is increased, then clotting is increased, and there is a risk of developing thrombosis. Growth can be observed when taking oral contraceptives and in the last months of bearing a child. A decrease in the prothrombin index indicates a deterioration in blood coagulation properties. The formation of prothrombin complex factors depends on vitamin K, therefore, its deficiency, malabsorption in the intestine (with dysbacteriosis, enterocolitis) can also lead to a decrease in PTI. Also, this can lead to taking large doses of acetylsalicylic acid, diuretics.

7. Thrombin time

This is the time during which fibrinogen is transformed into fibrin. Its normative value is 15-18 seconds. An increase in this indicator is noted with a congenital deficiency of fibrinogen or with severe liver damage. A decrease in the parameter, that is, a reduction in thrombin time, indicates the presence of paraproteins (proteins of the immunoglobulin class) or an excess of fibrinogen. Usually, the value of the indicator is monitored during treatment with fibrinolytics or heparin.

8. Antithrombin III

It is a thrombin inhibitor, a protein of the anticoagulant system. It has a depressing effect on the coagulation processes. The level of the indicator is determined by the binding in the control sample of thrombin (inhibition). The normal value of antithrombin III is 71-115 percent. A decrease in the parameter by 50 percent of the norm entails the risk of thrombosis.

Determining this indicator is especially important for expectant mothers taking anticoagulants. These drugs are used when carrying a child, when there is a threat of the formation of an abortion.

9. D-dimer

This is an important indicator for the diagnosis of thrombosis, which includes a coagulogram. What does this setting show? It allows you to identify the processes of thrombosis and dissolution of fibrin. Normal D-dimer is less than 248 ng/mL. The level of the indicator begins to gradually increase already at early dates pregnancy. By childbirth, the value of the parameter can exceed the initial value by three to four times. This is considered the norm. A higher rate is found in women who have a complicated pregnancy (preeclampsia), as well as in those who suffer from kidney disease, diabetes.

10. Platelets

These are platelets involved in ensuring hemostasis. They form in bone marrow. The standard value is 150-400 thousand / μl. In some cases, healthy women there may be a decrease in the number of platelets up to 130 thousand / μl. A significant decrease in the number of these blood elements is called "thrombocytopenia" and occurs as a result of a decrease in the formation of blood platelets, an increase in their consumption or destruction. With insufficient nutrition, the formation of platelets is reduced. With DIC, which will be discussed below, the consumption of the described shaped blood cells increases.

11. DIC

The interaction of platelets, the process of fibrinolysis and coagulation factors provides a balance between the anticoagulant and coagulation systems. If any of these links is violated, during pregnancy, quite serious complications. The most dangerous of them is disseminated intravascular coagulation. It develops due to the activation of the fibrinolysis system and the coagulation system. In pregnant women, the causes of DIC can be amniotic fluid embolism, premature placental abruption, endometritis.

12. Antiphospholipid Syndrome (APS)

It is a complex of symptoms that characterize thrombosis (venous and arterial). Women with APS have a high risk of miscarriage and spontaneous abortion, because in this case, the increase in the number of placental vessels is disturbed, and fetoplacental insufficiency develops. To diagnose antiphospholipid syndrome, in addition to increased thrombus formation, antibodies to the outer shell of membranes (phospholipids) are also determined.

Finally

The considered parameters of the coagulogram are not exhaustive. As noted above, the selection of specific parameters for the study depends on various factors. The results of the analysis will be available within a day after blood donation.