Why is a coagulogram analysis done? Coagulogram timing

To decipher the results of blood tests for coagulation during a coagulogram, you must have sufficient qualifications, but to understand the individual indicators of this test, the information below will be enough for you.

Blood sampling for coagulogram

FIBRINOGEN

Fibrin is necessary to convert blood into a clot so that bleeding can stop.

Testing for the presence of fibrinogen is carried out when it is necessary to predict the behavior of the human body during a surgical operation, if inflammation is suspected, for improved diagnosis of vascular and heart disease.

Standards in g/l:

adults: from 2 to 4;
babies up to one year: from 1.25 to 3;
newborns: from 1.3 to 3;
children from one year: from 2 to 4;
women during pregnancy: about 6.

Due to an increase in plasma fibrinogen levels, heart attacks and strokes occur. It can be a catalyst for thyroid dysfunction and a harbinger of cancer problems.

A low level indicates a lack of vitamins B12 and C, liver problems, toxicosis in women during pregnancy, and disseminated intravascular coagulation syndrome. A reduction is possible with treatment with anabolic steroids, taking fish oil and exposure to snake venom on the body.

Important! You can entrust the study of test results only to specialists.

Thrombin time (TV)

The time it takes for fibrin to transform into a blood clot when exposed to calcium is called thrombin.

The test is used in the following cases:

to determine the level of fibrinogen in plasma;
to understand the effect of fibrinolytics when treating a patient;
to confirm diagnoses of liver damage;
to detect miscarriage.

adults: from 14 to 16 sec;
women in position: from 18 to 25 seconds;
infants: 13 to 17 sec;
premature newborns: 14 to 19 sec;
children under 14 years old: from 13 to 16 seconds;
teenagers: from 12 to 16 sec.

Low values can be caused by blood clots, which can lead to blood vessel blockage and death.

High values confirm: autoimmune diseases, DIC syndrome in the patient, hereditary fibrinogen deficiency, vitamin K deficiency, use of anticoagulants in treatment, infection of the body.

PROTHROMBIN TIME

The time it takes for a clot to form during plasma coagulation is called prothrombin time and is measured in seconds. The norm is considered to be readings within the range of 11 to 16 seconds; in the case of taking samples from a pregnant woman, readings within 18 seconds are considered normal.

This test is performed during examination before surgery, to identify the general condition of the patient, and to identify anemia syndromes. In addition to these indications, the PTT test can be performed to confirm assumptions about the possibility of internal bleeding, detect liver pathologies, thrombosis and other diseases.

Important! In medical laboratories, testing for PTV is carried out using various methods, and only an attending physician with experience and sufficient qualifications can interpret the results correctly.

A decrease in PTT indicators is observed with: pregnancy, taking aspirin, increased red blood cell count, thrombosis.

An increase in PTT readings gives reason to suspect: problems with coagulation, the presence of disseminated intravascular coagulation syndrome, the use of warfarin, a lack of vitamin K, or an excess of antithrombin. In addition, taking antibiotics and hormonal agents can influence the increase in this indicator.

PROTHROMBIN INDEX

Its norm is from 95 to 105%, Kwik readings are from 78 to 142%.

Low levels indicate: lack of vitamin K, patient taking coagulants, liver damage, lack of fibrinogen, problems with blood clotting.

Indicators are exceeded: congenital deficiency of prothrombin and plasma Ac-globulin, acquired deficiency of blood coagulation, malfunction of the liver, lack of vitamin K. In addition, an increase in indicators can be caused by the use of antibiotics and anabolic steroids, hormonal drugs, aspirin.

ACTIVATE PARTIAL THROMBOPLASTIN TIME

This type of study is prescribed to confirm or refute symptoms: heart attack, thrombosis, intestinal necrosis, thromboembolism, vascular damage. Also reasons for testing may be bleeding, miscarriages, suspicion of DIC syndrome.

The normal APTT for adults is considered to be from 24 to 40 seconds, for infants just born from 25 to 43 seconds, for premature babies from 28 to 48 seconds.

Exceeding the norm shows a tendency to blood loss, but against the background of various diseases, and a decreased APTT value can confirm a lack of antihemophilic globulin, DIC syndrome in children.

A joint study of plasma with PTV allows for the identification of the following problems:

APTT is normal, PTT is higher: lack of vitamin K, liver damage, poor blood clotting according to the function of factor VII;
APTT normal, PTT normal, lupus anticoagulant detected: diagnosis of von Willebrand disease;
APTT is higher, PTT is higher: liver disease, fibrinogen deficiency, prothrombin deficiency;
APTT is lower, PTT is normal: decreased blood clotting is possible.

Indications for D-dimer testing

If the D-dimer shows no abnormalities, the version with thrombosis can be rejected. An increase in this marker indicates high coagulability and a predisposition to the formation of blood clots.

LUPUS ANTICOAGULANT

This marker is not isolated separately for research and is studied together with other markers in general tests.

INDICATORS OF COAGULOGRAM PROTEINS

Acceptable values of protein C in activity range from 70 to 130%, in quantitative measurement more than 3 mg/ml or 60 nmol/l.

Studies on this indicator are prescribed for hereditary protein deficiency in close relatives, to confirm or refute other blood tests, and if thrombosis is suspected.

PROTEINS

HEPARIN TOLERANCE OF PLASMA

Exceeding normal values by 7-15 minutes indicates poor tolerance to heparin and possible liver diseases, and low levels can be caused by cancer, heart failure, vascular problems and pregnancy.

RFMK OR SOLUBLE FIBRIN-MONOMER COMPLEX

The RFMC indicator normally ranges from 3.36 to 4 mg/100 ml.

An excess indicates thrombinmia, and levels below the permissible level most often occur when using anticoagulants.

DUKE BLEEDING TIME

This indicator is most often considered only together with others to obtain a more complete picture, and the norm is considered to stop bleeding within 1.5 to 2 minutes.

COLLATABILITY ACCORDING TO LEE WHITE

This analysis is carried out using glass or silicone tubes, and the test results, measured in minutes, are different for each type of tube. The norm for a glass test tube is from 4 to 7 minutes, and the norm for a silicone test tube is from 15 to 25 minutes.

Exceeding the readings indicates possible problems with the thyroid gland, serious blood loss or anaphylactic shock.

Deviation from the norm with a decrease in readings may indicate the use of anticoagulants, liver disease, severe infectious diseases, etc.

ANTITHROMBIN III

This marker is measured when venous thrombosis is suspected, with negative sensitivity to heparin, and after surgery to remove the blood clot. Antithrombin III is also considered in conjunction with protein indications.

The following absolute figures in % are considered acceptable:

for infants up to three days – 58-90;
over three days and up to one month – 60-89;
from one month to one year – 72-134;
from one year to six years – 95-134;
from six to eleven years – 96-126;
over 16 years – 66-124.

The indicators are specially calculated for pregnant women.

Exceeding the permissible values may indicate a lack of vitamin K, general problems with the liver and suspicion of viral hepatitis, possible inflammation in the body, prolonged exposure to warfarin or phenylin therapy, PMS in women.

Indicators below normal may indicate the body’s predisposition to the formation of blood clots, pregnancy in the last weeks. A decrease is also possible at the peak of PMS.

Attention! To correctly decipher a coagulogram, the doctor must have sufficient experience and qualifications.

Errors resulting from incorrect interpretation of results can lead to an incorrect diagnosis and the prescription of incorrect treatment.

A coagulogram is a blood test to measure its coagulability. It is important for doctors to know this result when preparing a patient for surgery. It is necessary to have data on blood clotting if a person has a disorder, if there is a history of diseases of the liver, cardiovascular and autoimmune systems, or varicose veins of the lower extremities. Using a coagulogram, the causes of bleeding are determined and the condition of a woman’s blood is monitored during pregnancy.

How to take a blood test for a coagulogram correctly - tips for taking the test

The blood clotting system is called hemostasis and protects the human body from excessive blood loss.

An analysis that tests the operation of this system is called hemostasiogram or coagulogram.

The endocrine and nervous functions of the body are responsible for the proper functioning of hemostasis. So that the blood successfully copes with its basic functions, it should be quite liquid. Thanks to blood circulation through the vessels, tissues are nourished, useful substances are transported to all organs, the immune system is in action, and the body is provided with normal thermoregulation.

Decreased blood clotting leads to to heavy blood loss in case of bleeding of various origins.

Hypercoagulation, on the contrary, to the formation of clots, that is, blood clots.

Since a coagulation test is vitally important, the doctor always wants to get accurate test data.

To properly donate blood for a coagulogram, you should properly prepare for the analysis. Exists a number of preparation rules, compliance with which guarantees the accuracy of the results:

Do not eat food for 8-12 hours before taking the analysis.
Recommended the day before in the evening, eat only a light dinner.
You can drink before the test but only ordinary drinking water.
Do not drink coffee or tea, juices or alcoholic beverages before the test..
Also recommended refrain from smoking for an hour before donating blood.
Immediately before blood collection you should take a coagulogram drink a glass of clean water.
15 minutes before donating blood, it is not recommended to overexert yourself emotionally or physically.
Before taking blood, you need to be calm, balanced and relaxed, not tense.
A patient taking medications that affect clotting should notify physicians about this.

Patients who experience symptoms of dizziness or fainting during blood sampling must warn the specialist who takes the test about this!

All blood coagulogram indicators - what each indicator means, explanation

Standard blood test for coagulogram includes many indicators. Professional decoding of the received data is carried out by qualified specialists, analyzing all parameters together.

Blood coagulation data are especially useful if the patient:

There is a tendency to form blood clots.
Postoperative, uterine or other bleeding has begun.
Treatment with anticoagulants is carried out.
History of stroke or heart attack.
There are vascular diseases.
Liver diseases are present.

The main indicators of the coagulogram are as follows:

Clotting time means the time interval between the time blood begins to flow from a wound, for example, when a finger is cut, and the moment when the blood stops because a fibrin clot forms in it. This interval normally for capillary blood ranges from 30 seconds to 3-5 minutes. Venous blood takes longer to clot – within 5-10 minutes. This indicator indicates how platelets cope with their work.

The duration of bleeding from the wound may be longer, if the platelet count is low for any reason, if there is a lack of vitamin C or the person has been taking anticoagulant medications for a long time, such as aspirin, or if hemophilia or liver disease. Blood clots faster after heavy bleeding and when using hormonal contraception.

Prothrombin index (PTI) measured as the ratio of the clotting time of the blood plasma of a healthy person, the so-called control blood, to the clotting time of the blood of the patient from whom the analysis is taken. The PTI value shows the condition of the human liver. During pregnancy, this indicator increases - this is normal. A pathological upward shift in the value of the prothrombin index occurs when using oral contraceptives, as well as if there is a risk of blood clots. When PTI decreases, there is a danger of bleeding.

When analyzing a blood coagulogram, the norm of the prothrombin index ranges from 93-107%. To maintain the normal state of this indicator, the body needs vitamin K.

Thrombin time normally equal to 15-18 seconds, measures the interval of conversion of fibrinogen to fibrin. If the thrombin time is less than normal, most likely there is excess fibrinogen in the blood. Prolongation of the thrombin gap is associated with a hereditary deficiency of this protein or with severe liver failure.

When using heparin in the treatment of a patient, this indicator must be strictly monitored!

Activated partial thromboplastin time (aPTT) - the most sensitive indicator of blood clotting, indicating the time of formation of a blood clot after combining calcium chloride with plasma and a number of other components. Normally, the APT coagulogram shows an interval of 30-40 seconds. The indicator is sensitive to changes in any other component of the coagulogram within 30 or 40 percent. An increase in aPTT is observed with vitamin K deficiency and liver diseases.
Activated recalcification time (ATR) helps to understand how one of the stages of blood clotting occurs. Normally, the indicator ranges from 50 to 70 seconds. If in the analysis the coagulogram avr is shorter than the normative one, then we can talk about a state of thrombophilia. When the time interval is extended, there is a danger of heavy blood loss in case of bleeding. An increase in recalcification time occurs due to a decrease in the number of platelets in the blood, during heparin therapy, in critical conditions such as burns, trauma, shock.
Fibrinogen concentration Normally ranges from 5.9 to 11.7 µmol/l. The rate decreases in diseases affecting the liver. It increases with malignant neoplasms, with a lack of thyroid hormones, and with acute infectious diseases.

Soluble fibrin-monomer complexes (SFMC) show changes in fibrin molecules under the influence of plasmin and thrombin. The upper limit of normal for RFMC per 100 ml is 4 mg. When studying the coagulogram rfmk, the decoding of the indicator serves as a marker of intravascular coagulation. Changing it depends on the same reasons as varying fibrinogen.
Thrombotest allows you to visually see the amount of fibrinogen contained in the blood. The norm is thrombotest grade 4 or 5.
Plasma tolerance to heparin shows the amount of thrombin in the blood. The analysis determines the time it takes for a fibrin clot to form in the blood plasma after heparin is administered to it. In normal blood of a healthy person this occurs in 7-15 minutes. A decrease in blood resistance to the action of heparin is indicated by a tolerance interval of more than a quarter of an hour. Heparin resistance decreases in liver diseases. The tolerance time will be less than seven minutes for hypercoagulation, characteristic of pregnancy, cancer, postoperative periods, and diseases of the cardiovascular system.
Fibrinolytic activity characterizes the ability of blood to independently dissolve blood clots. Fibrinolysin, which is capable of breaking down the structure of a blood clot, is responsible for this indicator in plasma. If blood clots dissolve faster than normal, it means the person has increased bleeding.

Duke bleeding time characterizes the bleeding time when pricking a finger with a special lancet. The injection is made to a certain depth - 4 mm. Then, every 15-30 seconds, using special paper, one drop of escaping blood is removed from the wound. In this case, the paper does not touch the finger. After removing one drop of blood, the time is noted when the next one comes out of the wound. In this way, the time to stop capillary bleeding is checked. Normally it is approximately 1.5 to 2 minutes. The result of this test is influenced by serotonin and blood platelets.
Fibrinogen is a protein synthesized by the liver. Under certain factors, it is converted in the hematopoietic system into the high molecular weight protein fibrin. Fibrin fibers serve as the basis for the formation of blood clots. The fibrinogen content in healthy blood should be within 2-4 g/l.

A coagulogram shows a dangerous decrease in fibrinogen levels when:

Toxicosis during pregnancy.
Malfunctions in hemostasis.
Cirrhosis of the liver.
Severe form of hepatitis.
Lack of B vitamins and ascorbic acid.
Taking fish oil.
Use of anabolic steroids and anticoagulants.

Fibrinogen content in the blood increases for pneumonia, acute infections and various inflammatory processes, after childbirth, during pregnancy, after operations, for burn injuries, hypothyroidism, heart attack or stroke, as a consequence of taking hormonal drugs.

Fibrinogen B – in a healthy blood test, this marker should be negative.
Blood clot retraction - its normal percentage level ranges from 44 to 65. This is an indicator of a decrease in the volume of a blood clot, its contraction with the release of blood serum. Increased retraction is characteristic of anemia. The decrease occurs due to an increase in the number of red blood cells and a decrease in platelets.
Plasma recalcification time (PRT) normally ranges from 60 to 120 seconds. This is one of the important indicators of hemostasis, which has something in common with AVR and records the clotting time of oxalate and citrate plasma, which is detected from the moment calcium salts are introduced into it. A reduction in recalcification time indicates hyperactivity of the coagulation system.

Blood coagulogram - table of normal indicators for adults and children

Main indicators of coagulogram - table of standards:

Children's indicators somewhat different. In particular, for newborns the fibrinogen norm is 1.25–3.00 g/l.

A blood coagulogram test is done for the child before any surgical intervention, if you suspect hemophilia or other anomaly of the hematopoietic system, with frequent nosebleeds.

A coagulogram (hemostasiogram) is one of the most important tests in laboratory blood tests. It is necessary for a detailed study of blood clotting ability.

It is prescribed, as a rule, when carrying a child, if the patient is predisposed to the formation of blood clots, and also before undergoing major surgery. Every person should have an idea of what kind of analysis this is, how it is carried out, and what it can show.

Description

A hemostasiogram is a laboratory study of blood fluid that allows one to evaluate hemostasis - a complex biosystem that is necessary to maintain the fluid properties of blood, promptly dissolve formed blood clots, and help stop bleeding.

To maintain basic functions, blood must meet the following requirements:

have a fairly liquid consistency, which allows you to provide vital organs and tissues with oxygen and necessary nutrients through their movement through the blood vessels, control the functioning of the body’s protective properties, and promote the elimination of toxic substances;
maintain a certain degree of viscosity to close gaps in blood vessels during injury.

If coagulability decreases to a critical level, then with intense bleeding the body dies.

Increased viscosity and blood clotting (hypercoagulation) provoke the formation of blood clots, which can trigger the development of stroke, thromboembolism or heart attack as a result of blocking important vascular systems.

Carrying out a coagulogram is necessary, since control over hemostasis helps prevent the formation of blood clots, blood loss and blockage of blood vessels.

This study is one of the most complex, since a specialist must have all the necessary knowledge to assess the state of not only each specific indicator, but also their totality.

Types of research

Hemostasiogram is classified into two types:

basic;
expanded (extended coagulogram).

The first type makes it possible to detect only existing disorders in hemostasis.

In the second, a full examination is carried out, which makes it possible to establish the cause of the pathological process and differentiate the disease from other disorders that have a similar consequence.

In addition, an important component is to conduct a qualitative and quantitative analysis of violations.

Why is it carried out?

The analysis includes the assessment of many indicators. Everything will depend on the goal. Each person has their own specific parameters.

In most situations, a coagulogram involves studying the following values:

Prothrombin. This is a complex protein, the amount of which indicates the general state of hemostasis. An increase in normal values indicates a predisposition to the formation of thrombosis, and a decrease indicates bleeding.
Norm of thrombosed index. Assess how long it takes for the patient's blood to clot.
Activated partial thromboplastin time is the period during which a blood clot forms.
INR is the ratio of thrombosed time to its average value. If the indicator is too high, then the patient is predisposed to bleeding, if too low, to thrombosis.
Fibrinogen. It is considered one of the main proteins in the formation of a blood clot during the clotting period. Its increase will indicate the development of inflammation. In addition, disturbances in the functioning of the heart and vascular system are possible. If the protein is present in reduced quantities, then we can talk about liver disease or a predisposition to bleeding.
Antithrombin 3. Helps reduce clotting.
Thrombosed time is the duration of the final stage of coagulation.
Platelet concentration.
D-dimer. Necessary for controlling the thrombus formation process. If it increases rapidly, the risk of having blood diseases, kidney diseases or diabetes mellitus increases.
. In normal condition it should not be there. The presence of this parameter indicates autoimmune disorders in the human body.

During the study, all 3 stages of blood clotting must be checked.

When is it appointed?

According to the advice of most experts, a coagulogram should be done before surgery, regardless of its complexity. In addition, the analysis is necessary during pregnancy.

Also among the indicators for biochemical analysis are:

severe gestosis in pregnant women;
preparation for surgery;
varicose veins;
high tendency to thrombosis;
the use of a certain number of medications that can affect blood clotting;
cirrhosis;
acute inflammation;
diseases of the cardiovascular system (ischemia, atrial fibrillation).

Often, a hemostasiogram is prescribed to assess the general state of hemostasis, as well as to monitor the patient’s condition during therapeutic measures that involve treatment with anticoagulants.

The study is also done in cases of serious prolonged bleeding or hematomas on the body, which can form even in the absence of mechanical damage.

Normal indicators

Normally, the values of the parameters in adults are equal to those given in the table below.

Clotting time
Prothrombin index
Thrombin time	11-17.8 seconds
Fibrinogen concentration
Fibrinogen	5.9-11.7 µmol/l
Fibrinogen B	negative
Fibrinolytic activity	183-263 minutes
Activated recalcification time (ATR)	50-70 seconds
Activated partial thromboplastin time (aPTT)	24-35 seconds
Thrombotest	IV-V degree
Plasma tolerance to heparin
Duke bleeding time
Blood clot retraction
Soluble fibrin-monomer complexes ()	up to 4 mg/100ml
Plasma recalcification time (PRT)	60-120 seconds

In children, as a rule, the data are somewhat different. During the newborn period, fibrinogen should be in the range of 1.25-3.00 g/l.

Standards in childhood:

For pregnant women, the indicators will be as follows:

Indicator	1st trimester	2nd trimester	3rd trimester
Platelets
Fibrinogen



Antithrombin III

How to donate blood for analysis

To get the most reliable results, you need to properly prepare for the study.

Preparation

Before screening, the patient must follow all the recommendations given by the specialist:

Avoid eating 12 hours before the session. If you cannot avoid having dinner the night before, preference should be given to light dishes.
Stop taking all medications that require short breaks.
Eliminate any drinks from your diet, especially alcohol. You are allowed to drink clean water.
Reduce physical activity.
Do not expose the body to stress.
Do not smoke at least one hour before the procedure.

If you do not follow these rules, the likelihood of receiving unreliable data increases.

Carrying out

They donate blood for analysis exclusively on an empty stomach. You can take it from a finger or a vein.

After all the instruments and the place from which the biomaterial is taken are disinfected, the laboratory technician makes a puncture in an area of the skin with minimal trauma, which must also be observed to prevent data distortion as a result of penetration of thromboplastin tissue.

To eliminate this possibility, it is necessary to fill two test tubes with the material. The latter is sent for research. If blood is taken from a vein, then a tourniquet is not used.

In addition, a special substance - a coagulant - must be added to the test tube.

The procedure itself is painless. Unpleasant sensations arise only at the moment of puncture of the skin. After a coagulogram, slight weakness may be observed in the arm.

Data interpretation

The interpretation of the results is carried out exclusively by a specialist. In this case, all the indicators that were described above are taken into account.

When making a final diagnosis, it is also necessary to take into account the medical history, the results of the patient’s examination, and a general blood test.

Generally speaking, exceeding the parameters of normal values will indicate thickening of the blood fluid, and a decrease will indicate a deficiency of platelets in the blood.

How many days does the study last?

The length of time required for the study will depend on many predisposing factors.

In most cases, a coagulogram is done for a maximum of 1-2 days. Sometimes this can take a maximum of ten days. Everything will depend on the serviceability of the equipment, the workload of the laboratory and the employee. If there is an additional charge for urgency, test results are issued on the day of delivery.

Coagulogram for children

The procedure is prescribed for a child in the following cases:

surgical intervention is planned;
Frequent bleeding is diagnosed, and there are also wounds that take a long time to heal.

In addition, a blood test is necessary if there is a suspicion of the development of pathological processes that negatively affect blood clotting.

When done to pregnant women

During pregnancy, the body undergoes a restructuring for upcoming motherhood. The changes do not bypass the hemostasis system, which is caused by hormonal imbalance and the formation of an additional blood circulation.

During this period, coagulogram parameters will indicate increased activity of factors that are responsible for blood clotting, as well as an increase in fibrinogen.

Parts of fibrin begin to be deposited on the vascular walls of the uteroplacental circle. Against this background, the process of fibrinolysis is suppressed, preventing thrombus formation and placental abruption.

These changes make it possible to protect the expectant mother’s body from natural abortion and the development of bleeding in the uterus.

If the period of bearing a child is complicated by pathologies and the manifestation of gestosis, blood clotting is impaired.

In the absence of timely treatment, DIC syndrome may develop, which is characterized by the formation of a large number of small blood clots and impaired blood flow to the fetus. In more severe cases, uterine bleeding cannot be ruled out, which is dangerous not only for the fetus, but also for the life of the woman.

To prevent such conditions, it is recommended to do a hemocoagulogram every trimester.

Cost of the procedure

The price will depend on the equipment used and the scope of work performed. For example, a basic study will cost 700-1500 rubles. The cost of the extended one will vary within 3,500 rubles.

During pregnancy, if you have a compulsory health insurance policy, the procedure is carried out free of charge, since examination in this case is mandatory.

A coagulogram is one of the most important laboratory techniques, which allows you to determine all the parameters of blood fluid coagulation.

The procedure is prescribed before surgery, for cardiac pathologies or during pregnancy. The results obtained allow us to assess the risks of blood clots or bleeding.

Blood is the main liquid medium of the body, and the quality of life and human health directly depend on its properties. One of the important properties of blood is fluidity, which ensures the ability to deliver nutrients to cells and participate in the process of removing metabolic products.

Hemostasis, the coagulation system, is responsible for the normal state of the blood—its fluid. Hemostasis maintains the necessary state, preventing both life-threatening bleeding and the formation of blood clots. To assess the operation of this system, the blood is examined for a coagulogram, or as it is also called a hemostasiogram.

What is a coagulogram?

A coagulogram is a comprehensive diagnostic that studies individual indicators of blood clotting. The name itself is derived from two words - Latin coagulum, which means coagulation, and Greek - gramma, which translates as line or image. That is, based on this phrase, the study implies a digital expression or graphical representation of the results obtained when assessing coagulation indicators.

And if we consider diagnostics in a broader sense, then it turns out that the entire hemostatic system. The study of venous blood using coagulometry (which means measuring coagulability) allows us to draw a conclusion about the state and quality of functioning of the components of hemostasis. This includes anticoagulation, coagulation and fibrinolytic functions.

A blood test for a coagulogram is carried out to assess the potential risks of hypo- and hypercoagulation, which is expressed in a decrease or increase in coagulability, and, consequently, the likelihood of bleeding or thrombosis. Correct and timely interpretation of the study data allows the doctor to assess the patient’s current condition, make a prediction of the outcome of the operation and prescribed therapy, and also be prepared for childbirth with possible complications.

In some cases, this analysis is almost the only guarantee for the patient. All parameters included in a comprehensive blood test for a coagulogram are considered to be indicative. There are 13 of them in total, but deviations from the normal values of any of them can lead to serious consequences for a person.

Table of parameters determined during a hemostasiogram

When is analysis necessary?

There are quite a few indications for prescribing a hemostasiogram, since deviations in the functioning of the coagulation system lead to a large number of diseases. Therefore, examination will be recommended in the following situations:

assessing the activity of the hemostatic system;
routine diagnostics before surgery;
preparation for self-delivery or cesarean section;
monitoring of severe gestosis that occurs with complications;
observation when taking oral contraceptives, anabolic steroids, glucocorticoid hormones;
control of anticoagulation therapy carried out with indirect-acting drugs (Warfarin, Aspirin, Trental) and heparin therapy (Clexane, Fraxiparine).

Also, the technique is necessarily prescribed for identifying diseases, as primary screening and as a regular check. A hemostasiogram is used to determine or confirm:

varicose veins of the venous vessels of the lower extremities;
DIC (disseminated intravascular coagulation) syndrome;
chronic liver pathologies – cirrhosis and inflammatory processes;
hemorrhagic diseases - hemophilia, thrombocytopenia and thrombocytopathy, von Willebrandt disease);
thrombosis of various organs - vessels of the lower and upper extremities, intestines, brain (stroke), pulmonary thromboembolism (TE).

A blood coagulogram examination is always carried out if there is a high risk of thrombosis. Such diseases include coronary heart disease (CHD) and atrial fibrillation.

Sequence of the coagulation process

What is the preparation?

To donate blood for clotting, the patient does not have to perform any complex actions, it is enough to just meet a few simple conditions, such as:

come to the procedure with an empty stomach, since the biomaterial is taken strictly on an empty stomach, and it would be correct to refrain from eating for at least 12 hours;
at least one day before the test, exclude spicy, fried, fatty foods, as well as smoked foods, marinades and alcohol from the diet;
You should stop smoking at least an hour before donating blood.

In addition, it is recommended to stop taking direct and indirect anticoagulants, since their effect will affect the hemostasiogram parameters. Of course, such permission to cancel must be agreed upon with the attending physician. Indeed, in some cases, independent withdrawal of drugs of this effect can lead to recurrent thrombosis.

If the attending physician does not allow you to stop taking the drug for a day or two before the procedure, then before taking blood you should notify the laboratory technician in the diagnostic room. All necessary information can be obtained in advance by contacting the clinic chosen for the examination. The receptionist will tell you in detail where the blood is taken from, how long the analysis takes, and will answer all the patient’s questions.

Blood collection procedure

The algorithm for donating biomaterial to determine coagulation parameters is in many ways similar to a typical blood draw, but in some ways it differs from standard procedures. Basic rules that must be followed when taking blood for a hemostasiogram:

Blood is drawn using a dry sterile syringe or a Vacutainer vacuum sampling system;
For the procedure, a needle with a wide bore is used, which makes it possible not to use a tourniquet;
the puncture of the vein must be clear - without damaging nearby tissues, otherwise the test tube will have an increased content of tissue prothrombin, which will affect the reliability of the results;
a laboratory technician or nurse collects 2 test tubes, but sends only the second one, which contains a special coagulant - sodium nitrate, for testing.

Where can I donate blood and when will the results be ready?

You can undergo blood coagulogram diagnostics in any medical diagnostic institution, both public and private, which has specialized equipment and the necessary reagents. This procedure is a rather complex study in terms of interpretation, so interpretation of the blood clotting test should be carried out by qualified doctors.

The cost of diagnostics depends on the number of indicators determined. The analysis time can also be lengthened, since studying each parameter requires a series of chemical reactions. In most cases, results are ready in 1-2 business days. In addition, the speed may be affected by the presence or absence of reagents, workload of the laboratory or courier.

Interpretation of indicators

As mentioned above, a hemostasiogram is a very complex and informative analysis, and it is interpreted exclusively by specialized specialists. Sometimes the attending physician may prescribe several parameters for the study, which will be indicated in the referral, and in some cases, all parameters of the coagulogram are studied. These include the following.

Prothrombin time (PT)

The value shows the time period during which, when thromboplastin and calcium are added to the plasma, a thrombin clot has time to form. The parameter determines the 1st and 2nd phases of plasma coagulation and the activity of factors listed in generally accepted tables under numbers 2, 5, 7, 10.

PV standards for adults and children of different age categories

Important! Treatment with anticoagulants is considered effective if the PT increases by at least 1.5–2 times.

International normalized ratio (INR)

The indicator is the prothrombin coefficient, that is, the ratio of the PT of the subject to the PT of the control tube. This parameter was introduced by WHO - the World Health Organization to streamline the activities of laboratories in 1983, since each uses different thromboplastin reagents. The main task of INR is to monitor the condition of patients taking indirect anticoagulants.

The main reasons for the increase in PT and INR include:

intestinal enteropathies, dysbiosis, accompanied by a lack of vitamin K;
amyloidosis is a systemic disease characterized by impaired protein metabolism;
genetically determined deficiency of 2, 5, 7, 10 coagulation factors;
therapy with coumarin-based medications (Merevan, Warfarin);
liver diseases – cirrhosis, chronic hepatitis;
decrease in concentration or absence of fibrinogen;
DIC syndrome and nephrotic syndrome;
the presence of anticoagulants in the blood.

The following factors lead to a decrease in these coefficients:

activation of fibrinolysis function (dissolution of blood clots);
thrombus formation in vessels and TE;
increase in the work of 7 factors.

Activated partial thrombin time (aPTT)

This value is also called cephalinkaolin time, and it determines the effectiveness of the functioning of plasma factors in stopping bleeding. In other words, APTT reflects the internal work of hemostasis, that is, the rate of creation of a fibrin clot. This is the most accurate and sensitive coagulogram value.

Its parameters, first of all, may vary depending on the activator reagents used in a particular clinic. A reduction in the coefficient indicates an increase in coagulability and a tendency to thrombosis, and a lengthening indicates a decrease in hemostatic function and the possibility of bleeding.

The reasons leading to an increase in APTT are:

liver pathologies occurring in severe form - fatty infiltration, cirrhosis;
congenital coagulation deficiency 2, 5, 8, 9, 10, 11, 12 factors;
therapy with heparin and its derivatives (Clexane, etc.);
autoimmune systemic connective tissue diseases (SCTDs) – systemic lupus erythematosus (SLE);
excess fibrinolysis activity;
2 and 3 degrees of DIC syndrome.

And, conversely, a decrease in APTT is caused by:

increased coagulation capacity;
Stage 1 of DIC syndrome;
ingress of tissue thromboplastin into a blood sample due to incorrect technique for taking biomaterial.

INR parameters that determine the required dose for a patient during warfarin therapy

Activated recalcification time (ATR)

The value reflects the time taken for fibrin to appear in plasma containing calcium and platelets, which indicates the quality of contact between plasma and hemostasis components. The AVR coefficient may vary depending on the reagents used.

Attention! An increase in the indicator is directly related to a decrease in the number of platelets, a change in quality characteristics, as well as hemophilia. A decline in AVR signals the possibility of thrombosis formation.

Prothrombin index (PTI)

The parameter displays the ratio of the ideal PTV to the identical value of a specific subject, multiplied by 100%. Recently, as a rule, experts refuse to determine this value and replace it with INR. PTI, like INR, smooths out differences in test responses that arise due to differences in reagents in laboratories. Changes in this parameter are in many ways similar to INR, that is, they are caused by almost the same aspects.

Thrombin time (TV)

The value is demonstrated by the final stage of hemostasis - the rate of fibrin clot formation in plasma when thrombin is added. The indicator is one of the three mandatory factors for study, together with aPTT and PT, and is used to monitor heparin therapy and congenital fibrinogenic anomalies.

Among the conditions that increase TV are:

absence of fibrinogen or its drop to less than 0.5 g/l;
taking fibrinolytic medications;
autoimmune pathologies (with the production of antibodies to thrombin);
chronic liver diseases – hepatitis, cirrhosis;
acute fibrinolysis, DIC syndrome.

A decrease in the indicator is observed with heparin therapy or the use of ICE (fibrin polymerization inhibitors), as well as at the 1st stage of development of DIC syndrome.

Table of factors by numbers and their main brief characteristics

Fibrinogen

This indicator, which is a protein compound, refers to 1 coagulation factor. It is synthesized in the liver, and when exposed to factor 7 (contact or Hageman) it is transformed into insoluble fibrin. The appearance of fibrinogen is characteristic of the acute phase, when its level increases during injuries, inflammation, infections and stressful situations.

An increase in fibrinogen concentration is caused by:

inflammatory processes occurring in severe form - peritonitis, pneumonia, pyelonephritis;
myocardial infarction, oncological tumors, especially those localized in the lungs, amyloidosis;
gestation and complications during pregnancy, menstruation;
surgical operations performed, burn disease;
therapy with heparin and its derivatives, as well as estrogens;
CTD – scleroderma, SLE, rheumatoid arthritis;
use of oral contraceptives.

A decrease in fibrinogen values is associated with the following conditions:

congenital and acquired deficiency;
DIC syndrome, status after severe bleeding;
liver disease due to alcoholism, cirrhosis;
red bone marrow aplasia, leukemia;
malignant neoplasm of the prostate gland;
excess heparin - refers to acute conditions, and protamine, which is an antidote to fibrin, is used for its treatment;
taking anabolic steroids, barbiturates, valproic acid, androgens, fish oil, (IPF).

Soluble fibrin-monomer complexes (SFMC)

RFMK are intermediate results of the dissolution of a fibrin clot, formed during fibrinolysis. They are quickly eliminated from plasma, so this parameter is quite difficult to study. Its main significance in terms of diagnosis is the early detection of DIC syndrome. The indicator increases:

in case of thrombus formations of different localization - deep veins of the arms or legs, pulmonary artery thrombosis;
acute and chronic forms of renal failure;
complications of pregnancy - preeclampsia, gestosis;
CTD, shock, sepsis, etc.

Important! An increase in RFMC may also be observed in the postoperative period, which will indicate the development of abnormalities in hemostasis.

Antithrombin III

This blood component is classified as an anticoagulant of physiological origin. This is a glycoprotein that inhibits thrombin and 9, 10, 12 coagulation factors. It is formed in hepatocytes (liver cells). This coefficient may increase in severe inflammatory pathologies - pyelonephritis, pneumonia, peritonitis, therapy with glucocorticoids or anabolic steroids, acute damage to the liver parenchyma (for example, hepatitis), vitamin K deficiency.

Antithrombin III norm values for different age categories

A decrease in values is noted due to:

chronic pathological processes of the liver that have developed in connection with alcoholism (cirrhosis, etc.);
DIC syndrome, ischemic heart disease, thrombosis and TE, sepsis;
congenital or acquired deficiency;
heparin and ICE therapy.

Also, a decrease in this parameter is observed in pregnant women in the 3rd trimester.

Features of coagulogram during pregnancy

During the period of gestation, multiple changes occur in the female body, affecting all systems, not excluding hemostasis. Such changes are caused by a hormonal surge and the formation of a second circulation. When a woman becomes pregnant, then her activity of coagulation factors 7, 8, 10, and especially fibrinogen, sharply increases.

Fibrin elements are deposited on the vascular walls of the uterus and placenta. Fibrinolysis is suppressed. Thus, the female body is insured in case uterine bleeding occurs and there is a threat of spontaneous abortion. These changes are aimed at preventing placental abruption and the formation of blood clots in the vessels feeding the uterus, and, in particular, the fetus.

With pathological gestation - gestosis of the early and late periods, disturbances in the functioning of hemostasis may develop. This manifests itself in an increase in fibrinolysis activity or a decrease in platelet lifespan. If a woman did not undergo examinations on time, such as a general (clinical), biochemical blood test, coagulogram, and, therefore, did not receive qualified help, then the risk of developing DIC syndrome is very high.

Hemostasiogram indicators during pregnancy

This pathology occurs in three phases, which pose a serious threat to both mother and child. Hypercoagulation is the formation of many small clots in a woman’s blood, causing disruption of the blood circulation between mother and fetus. Hypocoagulation - at this stage, clotting factors are depleted and clots disintegrate. Acoagulation is a lack of coagulation function, which causes uterine bleeding, creating risks for the life of the mother, and the child in such a situation most often dies.

General information about the study

The hemostasis system consists of many biological substances and biochemical mechanisms that ensure the preservation of the liquid state of the blood and prevent and stop bleeding. It maintains a balance between clotting and anticoagulant factors. Significant violations of the compensatory mechanisms of hemostasis are manifested by the processes of hypercoagulation (excessive thrombus formation) or hypocoagulation (bleeding), which can threaten the patient’s life.

When tissues and blood vessels are damaged, plasma components (clotting factors) participate in a cascade of biochemical reactions, which results in the formation of a fibrin clot. There are internal and external pathways of blood coagulation, which differ in the mechanisms for triggering the coagulation process. The internal pathway is realized when blood components come into contact with the collagen of the subendothelium of the vessel wall. This process requires coagulation factors XII, XI, IX and VII. The extrinsic pathway is triggered by tissue thromboplastin (factor III) released from damaged tissue and the vascular wall. Both mechanisms are closely interrelated and from the moment the active factor X is formed they have common paths of implementation.

The coagulogram determines several important indicators of the hemostatic system. Determination of PTI (prothrombin index) and INR (international normalized ratio) allows you to assess the state of the external blood coagulation pathway. PTI is calculated as the ratio of the standard prothrombin time (the clotting time of control plasma after the addition of tissue thromboplastin) to the clotting time of the patient's plasma and is expressed as a percentage. INR is a prothrombin test standardized in accordance with international recommendations. It is calculated by the formula: INR = (patient's prothrombin time / control prothrombin time) x MICH, where MICH (international sensitivity index) is the sensitivity coefficient of thromboplastin relative to the international standard. INR and PTI are inversely proportional indicators, that is, an increase in INR corresponds to a decrease in the patient’s PTI, and vice versa.

Studies of PTI (or a similar indicator - prothrombin according to Quick) and INR as part of a coagulogram help to identify disorders in the external and general blood coagulation pathways associated with a deficiency or defect of fibrinogen (factor I), prothrombin (factor II), factors V (proaccelerin) , VII (proconvertin), X (Stewart-Prower factor). With a decrease in their concentration in the blood, the prothrombin time increases in relation to control laboratory parameters.

Plasma factors of the extrinsic coagulation pathway are synthesized in the liver. For the formation of prothrombin and some other coagulation factors, vitamin K is required, the deficiency of which leads to disturbances in the cascade of reactions and prevents the formation of a blood clot. This fact is used in the treatment of patients with an increased risk of thromboembolism and cardiovascular complications. Thanks to the prescription of the indirect anticoagulant warfarin, vitamin K-dependent protein synthesis is suppressed. PTI (or Quick prothrombin) and INR coagulation are used to monitor warfarin therapy in patients with factors that promote thrombosis (for example, deep vein thrombosis, the presence of prosthetic valves, antiphospholipid syndrome).

In addition to prothrombin time and related indicators (INR, PTI, prothrombin according to Quick), other indicators of the hemostatic system can be determined in the coagulogram.

Activated partial thromboplastin time (aPTT) characterizes the intrinsic pathway of blood coagulation. The duration of APTT depends on the level of high molecular weight kininogen, prekallikrein and coagulation factors XII, XI, VIII and is less sensitive to changes in the levels of factors X, V, prothrombin and fibrinogen. APTT is determined by the duration of blood clot formation after calcium and partial thromboplastin are added to the blood sample. An increase in aPTT is associated with an increased risk of bleeding, a decrease is associated with thrombosis. This indicator is used separately to monitor therapy with direct anticoagulants (heparin).

Fibrinogen is a blood clotting factor I produced in the liver. Thanks to the action of the coagulation cascade and active plasma enzymes, it is converted into fibrin, which is involved in the formation of a blood clot and thrombus. Fibrinogen deficiency can be primary (due to genetic disorders) or secondary (due to excessive consumption in biochemical reactions), which is manifested by impaired formation of a stable blood clot and increased bleeding.

Fibrinogen is also an acute-phase protein; its concentration in the blood increases in diseases accompanied by tissue damage and inflammation. Determining the level of fibrinogen as part of a coagulogram is important in the diagnosis of diseases with increased bleeding or thrombus formation, as well as for assessing the synthetic function of the liver and the risk of cardiovascular diseases with complications.

The blood anticoagulation system prevents the formation of excess amounts of active clotting factors in the blood. Antithrombin III is the main natural inhibitor of blood clotting, which is synthesized in the liver. It inhibits thrombin, activated factors IXa, Xa and XIIa. Heparin enhances the activity of antithrombin 1000 times, being its cofactor. The proportional ratio of thrombin and antithrombin ensures the stability of the hemostatic system. With primary (congenital) or secondary (acquired) AT III deficiency, the blood coagulation process will not be stopped in a timely manner, which will lead to increased blood clotting and a high risk of thrombosis.

The formed thrombus undergoes fibrinolysis over time. D-dimer is a fibrin degradation product that allows the fibrinolytic activity of plasma to be assessed. This indicator increases significantly in conditions accompanied by intravascular thrombosis. It is also used in dynamic monitoring of the effectiveness of anticoagulant therapy.

What is the research used for?

For a general assessment of the blood coagulation system.
For the diagnosis of disorders of the internal, external and general pathways of blood coagulation, as well as the activity of the anticoagulant and fibrinolytic systems.
To examine the patient before surgery.
To diagnose the causes of miscarriage.
For diagnosing DIC syndrome, venous thrombosis, antiphospholipid syndrome, hemophilia and assessing the effectiveness of their treatment.
To monitor anticoagulant therapy.

When is the study scheduled?

If DIC syndrome or pulmonary embolism is suspected.
When planning invasive procedures (surgical interventions).
When examining patients with nosebleeds, bleeding gums, blood in the stool or urine, hemorrhages under the skin and in large joints, chronic anemia, heavy menstrual flow, sudden loss of vision.
When examining a patient with thrombosis, thromboembolism.
When lupus antibodies and antibodies to cardiolipin are detected.
With a hereditary predisposition to disorders of the hemostatic system.
With a high risk of cardiovascular complications and thromboembolism.
For severe liver diseases.
With repeated miscarriages.
When monitoring the hemostatic system against the background of long-term use of anticoagulants.