Prothrombin, prothrombin index and time: blood norms, analysis interpretation. Prothrombin test according to Quick: norm

The anti-clotting system keeps the blood fluid, while the clotting system prevents possible bleeding by forming blood clots.

blood clotting process

Briefly describe the clotting process, it will consist of the following phases:

  • prephase or vascular-platelet hemostasis;
  • prothrombinase;
  • thrombin;
  • fibrin;
  • postphase, which consists of two parallel processes: retraction (reduction and thickening of the thrombus) and fibrinolysis (dissolution of the thrombus).

Thus, for the formation of a thrombus, several components are necessary: ​​the wall of blood vessels, blood elements, as well as the plasma system of blood coagulation.

This process looks like this: damage to the vascular endothelium causes the activation of the enzymes of the coagulation system, which, in turn, forms fibrin filaments, which are the scaffold for the formation of a thrombus.

The clotting system is triggered in two ways:

1. External - upon contact of clotting factors with damaged tissues outside the vessel.

2. Internal-associated with destroyed blood cells and damage to the endothelium, that is, the process starts inside the vessel itself.

Prothrombin time is a special laboratory indicator that reflects the external pathway of activation of the blood coagulation system.

Often, prothrombin time is determined with activated partial thromboplastin time (APTT), which evaluates the intrinsic pathway of activation. Taken together, these two indicators reflect the systems of the coagulation and anticoagulation systems as a whole and its changes in the pathology of internal organs.

The norm of prothrombin time is 11-16 seconds.

Also, to determine the functions of the coagulation system, indicators are also determined - the prothrombin index and the international normalized ratio (INR).

The prothrombin index (PTI) is a percentage indicator determined by the ratio of the prothrombin time of the control plasma to the PTT of the human plasma under study. Normally, it should be 95-105%.

International Normalized Ratio (INR) – This study compares blood drawn from a patient with internationally normalized plasma.

The value of the norm can range from 0.85-1.25.

It should be borne in mind that during therapy with warfarin, the indicators may change, therefore, it is necessary to take into account the data of the anamnesis.

Determination of prothrombin time according to Quick

This type of study is the most accurate characteristic of the blood coagulation system and reflects the percentage of coagulation factors. Normal values ​​of prothrombin time according to Quick are 70-120%.

In order to determine the prothrombin time, fresh plasma from the patient under study is used. Blood is collected in a test tube with sodium citrate to bind blood calcium. Next, the sample is mixed, centrifuged, at a temperature of 37C, an excess amount of calcium is added to restore the blood's ability to clot. After that, tissue coagulation factor (better known as factor III) is added and the time of formation of a blood clot is noted.

It should be borne in mind that in some pathologies, the prothrombin time may be increased or decreased.

Prothrombin time is increased with:

1. Congenital deficiency of some blood coagulation factors such as II (prothrombin), V (Proaccelerin), VII (Proconvertin), X (Stuart-Prauer factor).

2. Acquired deficiency of blood coagulation factors resulting from diseases (chronic liver and kidney diseases, amyloidosis, autoimmune diseases).

3. Disseminated intravascular coagulation syndrome (DIC), which develops in blood diseases, including oncological ones.

4. The use of indirect anticoagulants (warfarin) in the main therapy.

5. Developing hypovitaminosis K (in diseases of the pancreas and gallbladder, dysbacteriosis, malasbortion syndrome).

6. An increase in the level of antithrombin in the blood.

The use of certain drugs also leads to an increase in prothrombin time (some antibiotics, steroid hormones, laxatives, acetylsalicylic acid in doses exceeding therapeutic ones).

Prothrombin time is reduced when:

1. Polycythemia.

2. Pregnancy in the last trimester.

3. Thrombosis of deep veins of the lower extremities.

4. The use of acetylsalicylic acid in small doses.

5. Taking oral contraceptives.

  • detailed examination of the whole organism;
  • pre and postoperative examination;
  • suspicion of a violation of the functions of hemostasis;
  • suspected occult bleeding;
  • suspicion or presence of thrombosis;
  • control of hemostasis functions during treatment with direct and indirect anticoagulants;
  • diagnosis of liver diseases;
  • a history of cardiovascular diseases and their complications, as well as thromboembolism of various organs;
  • diagnosis of nosebleeds and hemorrhages in various organs and tissues;
  • diagnosis of chronic anemia.

Preparation for a blood test for prothrombin time:

  • do not eat 12 hours before taking a blood test;
  • do not smoke before the study for 30-60 minutes;
  • limit physical and psycho-emotional stress;
  • if possible, cancel drugs that affect coagulation, or prescribe a study before starting therapy;
  • follow a diet, excluding fried and very fatty foods.

Prothrombin time during pregnancy

Analysis of the change in prothrombin time during pregnancy is one of the important diagnostic methods used in biochemical screening. Particular attention should be paid to this particular group of patients. Indications for periodic monitoring of prothrombin time in expectant mothers are:

1. A history of miscarriages, spontaneous abortions, missed pregnancies.

2. Hypertonicity of the uterus and other threatening conditions.

3. The presence of signs of preeclampsia in a pregnant woman at all stages of pregnancy.

The norm of prothrombin time during pregnancy is 11-18 s. If the PTT is elevated, then possible bleeding in the birth and postpartum periods should be assumed. If the prothrombin time is lowered, then it is necessary to be wary of the development of DIC.

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In the human body, there is a constant movement of blood - a life-giving fluid that provides nutrition to all cells of the body and metabolism. The length of the vessels is thousands of kilometers, and the area of ​​their location is more than half a hectare. It is impossible to imagine how all this is placed in the body of an adult.

But the amount of life-giving fluid is small: for men - a little more than five liters, and for women - about four. Therefore, when injuries or cuts violate the integrity of the circulatory system, its contents can quickly splash out, threatening a person with a fatal outcome.
If blood loss is not prevented, the main transport link that nourishes the entire body will cease to exist.

To prevent this from happening, nature has created a system responsible for blood clotting. It is she who is able to launch protective mechanisms that close the wound and prevent blood from leaving the vessels.

The value of prothrombin in the body

Part of this system are special plasma proteins, which are called blood coagulation factors. They are marked with Roman numerals from I to XIII. Prothrombin is one of the main components. This protein is a blood coagulation factor II.

The name "prothrombin" suggests that it is the precursor of thrombin, the active enzyme. With its assistance, a clot (thrombus) is formed, closing the wound and stopping blood loss.

A normal level of prothrombin indicates that the blood clotting process is working efficiently and the body will be able to stop the loss of this life-giving fluid in time.

Protein testing is not as common as clinical blood testing. This procedure is not easy and is prescribed only in case of emergency, for example, in case of blood diseases or if there are problems with its coagulation.

Determination of the level of prothrombin - the most important test in the hemostasiogram.

Norm of prothrombin

Prothrombin molecules break down very easily and quickly. It is difficult to separate them from other proteins, which makes it difficult to determine its level. Several methods are used for qualitative analysis.

  • Prothrombin according to Quick. Today this method is generally accepted and widespread. This technique provides for the calculation of the level of the substance as a percentage of the allowable amount. The following values ​​are considered optimal (%):
    • minimum - 70;
    • the maximum is 120.

    The indicator allows you to determine the activity of the prothrombized plasma complex in comparison with various dilutions of the patient's plasma. A graph of the change in prothrombin is drawn up, the construction of which is based on data on the time of blood clotting.

    Experts consider the analysis according to Quick to be the most accurate when low prothrombin levels are recorded.

  • Prothrombin index– is also defined as a percentage. The normal indicator is within the following limits (%):
    • minimum - 95;
    • the maximum is 105.

    The results of the two analyzes above may coincide if prothrombin is normal. But when its value is below the optimum, they diverge significantly. The index is highly dependent on the sensitivity of the chemicals used in the test.

  • prothrombin time- shows how many seconds the plasma folds after adding a special mixture to it.

    The final test results depend on age. In newborn babies, blood clotting time can be from 14 to 18 seconds. And these figures are normal. In adults, a gap of 10 to 15 seconds is considered optimal.

  • International Normalized Ratio - INR. This method is optional and is used to monitor the results of the prothrombin test.

    The INR method is recommended by WHO experts and other international organizations and committees that study thrombosis and are engaged in standardization in hematology. The results of such a test allow the doctor to control the effectiveness of treatment with anticoagulants - synthetic substances that reduce the content of prothrombin in the blood and slow down its clotting. These drugs are used in the treatment of thrombophlebitis, thrombosis, that is, diseases that form dangerous blood clots in venous vessels.

    The INR is normally 0.85–1.15.

    When treating diseases such as pulmonary embolism, venous thrombosis, or heart valve pathologies are present, the allowable limits increase to 3.0.

Indications for a prothrombin test

A blood test for prothrombin may be prescribed by a doctor in such cases:

  • the patient has bleeding that does not stop for too long (this clearly indicates that blood clotting is below normal levels);
  • the performance of liver enzymes and the liver as a whole is reduced;
  • to monitor coagulation with prolonged use of anticoagulants;
  • with antiphospholipid syndrome in order to clarify the cause of the disease;
  • if there are diseases that are accompanied by a lack of vitamin K in the body.

Some indirect reasons requiring an analysis for prothrombin are exclusively individual in nature. Most often, the study is assigned to the fair sex aged 50 to 60. It is at this time that hormonal changes occur that cause a change in the composition and structure of the blood.

The following doctors can prescribe an analysis:

  • therapist;
  • traumatologist;
  • surgeon;
  • cardiologist;
  • anesthesiologist-resuscitator;
  • pulmonologist;
  • pediatrician.

For research, blood from a vein is used. In order for the results to be as correct as possible, before the study, it is necessary to follow the standard rules:

  • dinner no later than 8 pm, at least 12 hours before testing;
  • before the study, be sure to put your nerves in order and not overstrain physically;
  • do not smoke on the day of the test and do not take strong drinks.

As usual, blood is taken in the morning on an empty stomach. It is necessary to inform the medical staff about all medications that have been taken in the last day.

Prothrombin is elevated

An increased content of prothrombin in the blood indicates that blood clotting is more than normal. This means that it becomes too viscous, which impedes blood circulation and leads to blockage of blood vessels.

The following ailments can provoke an increase in the content of prothrombin, and hence blood clotting:

  • malignant neoplasms;
  • liver pathology;
  • thromboembolism;
  • polycythemia;
  • progressive angina.

An increase in the amount of protein can also be caused by such factors:

  • an excess of vitamin K in the body, with the help of which prothrombin is produced;
  • use in therapy of anticoagulants, antibiotics, nicotinic acid, hormonal contraceptives. Excessive use of aspirin, anabolics, laxatives can also affect the growth of prothrombin.

Quite often, the protein content increases during childbearing. Most often it manifests itself in the last trimester and does not need treatment.

Prothrombin is lowered: causes

A low level of prothrombin is dangerous because even a small injury that damages a blood vessel can result in significant blood loss. After all, the formation of a blood clot is slower than it should be.

A decrease in the level of prothrombin is provoked by such reasons:

  • Individual pathologies of the liver, although most of them are accompanied by an increase in protein. The content of prothrombin decreases in acute and chronic forms of hepatitis. The same is true for cirrhosis of the liver.
  • Insufficient synthesis of vitamin K by the body. This process develops most often due to gastrointestinal ailments and dysbacteriosis.
  • Deficiency of fibrinogen - a protein that is produced in the liver and then converted into fibrin, which is the basis of a clot during blood clotting. Such a deficiency can be both congenital and acquired.
  • Reception for medicinal purposes of drugs that promote the growth of blood clotting.

It is possible to bring the level of prothrombin back to normal, but something should be done only after consulting a specialist.

Therapy is aimed at eliminating the ailments that caused the problem. Quite often, the basis of treatment is a special diet.

An increase in prothrombin time indicates a tendency to hypocoagulation and may depend on various causes.

  • Deficiency of one or more factors of the prothrombin complex, which is observed in such hereditary coagulopathies as hypoproconvertinemia (factor VII deficiency) and hypoprothrombinemia (factor II deficiency).
  • The increase in prothrombin time sometimes observed in amyloidosis is associated with a deficiency of factor X, which is absorbed by amyloid, and in nephrotic syndrome, with a deficiency of factors VII and V, which are excreted in the urine.
  • The synthesis of factors of the prothrombin complex occurs in the liver cells, with diseases of the latter, their number decreases, so the prothrombin time to a certain extent can serve as an indicator of the functional state of the liver. An increase in prothrombin time is noted in acute and chronic hepatitis, cirrhosis of the liver, with subacute liver dystrophy and other lesions of the liver parenchyma, which is considered a poor prognostic sign. At the same time, the reason for the increase in prothrombin time may also be the malabsorption of vitamin K, which is necessary for the synthesis of factors of the prothrombin complex, which develops as a result of a decrease in the flow of bile into the intestine. This is the same reason for the increase in prothrombin time in obstructive jaundice.
  • Enteropathy and intestinal dysbiosis leading to vitamin K deficiency may also be accompanied by an increase in prothrombin time.
  • When treated with vitamin K antagonists (anticoagulants of indirect action), the final stage of the synthesis of prothrombin complex factors is disrupted, and the prothrombin time is lengthened.
  • The consumption of prothrombin complex factors in acute DIC leads to a fairly early increase in prothrombin time (by 2 times or more).
  • In chronic pancreatitis, pancreatic and gallbladder cancer, an increase in prothrombin time may be the result of liver damage and / or the development of DIC.
  • Afibrinogenemia, hypofibrinogenemia (a decrease in the content of fibrinogen in the blood to 1 g / l and below), as well as an excessive content of heparin in the blood, lead to an increase in prothrombin time.
  • Elongation of prothrombin time is detected in acute and chronic leukemia, due to the development of DIC.
  • An increase in the concentration of antithrombin or antithromboplastin in the blood also leads to a prolongation of the prothrombin time;
  • A whole group of drugs can lengthen prothrombin time: anabolic steroids, antibiotics, acetylsalicylic acid (in high doses), laxatives, methotrexate, nicotinic acid, quinidine, thiazide diuretics, tolbutamide.

A shortening of the prothrombin time indicates a tendency to hypercoagulability and can be noted in the initial stages of deep vein thrombosis of the lower extremities, with polycythemia, in the last months of pregnancy. Shortening of prothrombin time is caused by the following drugs: acetylsalicylic acid (in small doses), mercaptopurine, oral contraceptives.

For certain diseases, a PTI blood test is prescribed, what it is and how to decipher it correctly. Blood is considered the fluid tissue of the body. It consists of 4 important components: red blood cells, platelets, white blood cells and plasma. Platelets are responsible for clotting. The amount of blood in each person is individual, but on average the total volume is from 4.5-5 liters.

The functions of blood are to transport nutrients and oxygen to all organs and tissues, protect against infections and thermoregulate. All this is possible due to its liquid state. However, blood tends to form clots or blood clots, which is also very important for the human body. In the event of injury or cuts, the blood cells react instantly. Due to the ability to clot, the blood forms a clot, which prevents bleeding.

Clots are formed due to a special protein - prothrombin, the precursor of thrombin. Prothrombin is produced by the liver with the help of vitamin K. A blood test for PTI (prothrombin index) allows you to determine the level of clotting. The study of blood functions for coagulability is called a coagulogram.

Description of blood parameters

When assigned, the base parameters are specified. It:

  • fibrinogen;
  • prothrombin index (PTI);
  • PTT, prothrombin time;
  • INR, international normalized ratio;
  • APTT, activated partial thromboplastin time;
  • thrombin time.

PTT, PTI, INR are indicators that determine the external pathway of blood coagulation. APTT allows you to determine the internal clotting pathway. The prothrombin index refers to the plasma clotting time. PTI indicators are written as a percentage. Since there are several methods for studying PTI, the indicators differ

In this blood test, reagents with different sensitivities are used. Therefore, WHO decided to use INR instead of IPT. Its norm is not affected by the methods of research and the choice of reagents. To calculate the prothrombin index, the patient's plasma clotting time is noted. At the same time, the clotting time of a standard plasma of a healthy person is recorded. The resulting indicators are called PTI.

The second method of studying PTI is carried out according to Quick. It is considered more reliable and the most popular. The activity of the prothrombin protein is determined using a calibration curve, in which the recording of results depends on normal plasma diluted in specific solutions.

Normal data

Deciphering a blood test for coagulation will help you understand which indicators are within the normal range and which indicate violations associated with serious diseases. The laboratory conclusion indicates the main indicators: fibrinogen, PTI; thrombin time, prothrombin time, APTT, prothrombin.

The amount of fibrinogen normally ranges from 2 g / l - 4 g / l. The increase occurs during pregnancy, infections, heart attack, hypothyroidism, burns, and the use of contraceptives. A decrease in this enzyme occurs with toxicosis, hepatitis, DIC, cirrhosis, treatment with certain drugs, vitamin C or B12 deficiency.

APTT is an indicator that reacts sharply to changes in other coagulation factors. The normal APTT is considered to be 30-40 seconds. This is the time it takes for a blood clot to form. With hemophilia, liver diseases, this figure increases. Thrombin is formed from prothrombin with the participation of vitamin K. Changes occur when the gastrointestinal tract is disturbed.

PTI is considered one of the most important indicators in the analysis of blood clotting. The PTI norm ranges from 93% to 107%. Deviation from the norm is observed in diseases of the liver, pregnancy, taking birth control pills. A decrease in the prothrombin index indicates that blood clotting is impaired. This phenomenon can be observed with a lack of vitamin K, intestinal diseases, taking blood-thinning medications (aspirin, cardiomagnyl or diuretics). Poor blood clotting increases the risk of bleeding.

The norm of thrombin time is 11-18 seconds. Thrombin time is the time when the protein fibrinogen is converted to fibrin. Prothrombin time is an indicator of the formation of thrombin from prothrombin (an inactive protein form). The rate of prothrombin according to Quick is 78-142%. Prothrombin time is normally 11-16 seconds.

When is it necessary to test blood for clotting?

The study of blood functions is especially important for pregnant women. This will help eliminate any risk of bleeding during the period of gestation and the upcoming birth. It is necessary to regularly examine blood for coagulability when:

  • functional changes in the liver;
  • taking medications that affect the process of hematopoiesis;
  • pathologies of the circulatory system;
  • vascular atherosclerosis;
  • autoimmune disorders;
  • lack of vitamins;
  • antiphospholipid syndrome;
  • oncological diseases;
  • previous stroke, heart attack;
  • preparation for surgery;
  • cardiovascular diseases (arrhythmias, angina pectoris, ischemic heart disease).

The reliability of a blood test for a coagulogram depends largely on preparation. Blood sampling is performed from a vein in the morning on an empty stomach or do not eat before blood sampling for about 4-6 hours. If at the time of the analysis the patient takes any drugs without fail, it is required to inform the doctor about this. On the eve it is forbidden to drink alcoholic beverages, coffee, strong tea. It is recommended to drink plain non-carbonated water.

The psychological state of the patient also affects the accuracy of the analysis. It is important to avoid stressful situations, excessive worries and worries. Muscle tension and stiffness adversely affects the internal processes of the body and can distort the results.

Sometimes the prothrombin index may be higher or lower than normal. this may indicate the presence of serious diseases.

Small changes can be caused not by pathologies, but by a temporary state of a person.

Women who constantly sit on various diets can bring the body to exhaustion. Deficiency of vitamins C, B 12, K affects blood functions.

In this case, an additional examination is prescribed to exclude the presence of pathologies. If the problem is a lack of vitamins, then no special treatment is required. It is enough to adjust the daily diet.

PTI below normal indicates:

  • lack of vitamin K;
  • an excess of heparin in the body;
  • malignant neoplasms in the pancreas;
  • amyloidosis (violation of protein metabolism);
  • DIC - syndrome;
  • renal pathologies;
  • gallbladder cancer;
  • leukemia;
  • pancreatitis in a chronic form;
  • dysbacteriosis;
  • insufficient production of fibrinogen due to congenital pathologies.

In addition to these factors, the use of antibiotics, antidepressants, corticosteroids and other drugs affects blood coagulation. An increase in PTI levels is called hypercoagulability. This means that the blood is too thick, which threatens with blood clots. Hypercoagulability can occur when:

  • the formation of malignant tumors;
  • polycythemia (a large number of red blood cells);
  • thrombosis;
  • taking certain medications;
  • pregnancy in the third semester.

A high degree of clotting occurs when taking barbiturates, oral contraceptives. In some cases, malnutrition and insufficient fluid intake can lead to thickening of the blood.

Symptoms of bleeding disorders

It is usually impossible to notice problems with blood clotting. But some of the symptoms are suggestive. People with low PTI may experience subcutaneous hematomas, with cuts, blood oozes longer than usual. Women suffer from profuse menstruation. With poor clotting, nosebleeds occur. See a doctor if you have these symptoms.

In medicine, the term "prothrombin time" is accepted to refer to the time of blood clotting. This important indicator is necessary for the diagnosis of serious diseases.

blood clotting process

In order to understand what prothrombin time (PTT) is, it is necessary to consider the process of blood coagulation.

Blood clotting is a complex process that starts when wounds appear. A blood clot forms on their surface, which prevents the infection from entering the body and at the same time prevents large blood loss. Responsible for this feature. When injured, it is modified into frequent fibrin filaments, similar to a network. They prevent blood from escaping from the wound. Thanks to fibrin, a thrombus is formed, which thickens over time, which leads to wound healing.

The coagulation process consists of three stages and is a complex chain of molecular interactions:

Activation. At this stage, prothrombin, a complex protein, passes into thrombin.

Coagulation. At this stage, fibrin is formed from fibrinogen.

Retraction. At the final stage, a dense fibrin clot, a thrombus, is formed.

However, this scenario does not always work. If a person has serious diseases, the clotting process is disrupted - this leads to an increase in the amount of time. As a result, the patient may begin to bleed heavily.

There are other violations of the coagulation process, when a blood clot forms too quickly. This is possible because the blood becomes thicker and more viscous. This happens as a result of some diseases. Early formation of blood clots is deadly for the body, because. can lead to sudden death from heart attacks, strokes, gangrene of the extremities and other serious diseases.

To prevent such dangerous pathologies and for their early diagnosis, a blood test is performed for prothrombin time.

Normal and pathological indicators of prothrombin time

To find out how the clotting system as a whole functions, coagulation tests are performed in clinical laboratories. They give an idea of ​​the work of the entire prothrombin complex. It includes:

Prothrombin time (PT), in seconds;

In percents.

Prothrombin index

Patients who are to be analyzed are wondering: what is the prothrombin index? This is one of the most important indicators.

This is the ratio of the clotting time of the plasma of a particular patient to the clotting time of the control plasma.

Normally, this indicator should not deviate from the boundaries of 95-105%. However, its reliability is often affected by the quality of the reagents used for analysis.

In doubtful cases, an analysis of the prothrombin index according to Quick is performed. It is considered more accurate. The results are also measured as a percentage, but the ratio is based on the activity of prothrombin to the results of measurements in control plasma solutions of different dilutions. Normal indicators of the prothrombin index according to Quick are 78 - 142%.

If the analysis showed a result less than the lower threshold value of the norm, hypocoagulation takes place. This term means a tendency to bleed. The following factors contribute to this:

Intestinal diseases that cause a lack of vitamin K, an important participant in the blood clotting process;

Taking medications to improve clotting;

Liver disease;

hereditary deficiency.

If the result of the analysis was a prothrombin index higher than the threshold value, then there are disorders associated with hypercoagulation, that is, increased prothrombin time for certain reasons. This leads to the formation of blood clots. This problem can be caused by a number of reasons, including:

Oncological diseases of the blood;

Chronic liver diseases;

bowel disease;

Obesity;

artificial heart valve;

Pregnancy;

Taking hormonal contraceptives;

the use of drugs to improve clotting, antibiotics, aspirin, quinine and laxatives.

Sometimes the prothrombized index is replaced by another definition of MSC - international standardized coefficients.

The indicators of prothrombin time should be monitored in the blood of women carrying a child. Elevated prothrombin time and index indicate disorders in the body of a pregnant woman. This should include both mature age, and stressful situations, and possible mutations in the genes of the fetus. Hypercoagulation syndrome is triggered in their body during pregnancy as a protective reaction associated with rapid blood loss during childbirth.

Prothrombin time and international normalized ratio

Prothrombin time in the analysis is indicated in seconds. The time interval required for the formation of a thrombus is determined.

The norm of prothrombin time is considered to be values ​​that do not go beyond 11-16 seconds.

If the prothrombin time is increased, this means that the patient develops a tendency to bleed, i.e. hypocoagulation.

In other words, prothrombin time is a coagulation test that determines the clotting time of the patient's plasma after adding a mixture of tissue thromboplastin and calcium ions to it.

The International Normalized Ratio is a measure that is calculated from the ratio of the patient's prothrombin time to the prothrombin time of an ideal sample in a blood test. The result will always be the same regardless of the laboratory and the reagents used there.

Normal indicators of INR in an adult healthy person are considered to be in the range of 0.7 - 1.3%.

The results for men will be no different from the results for women. If the patient takes blood thinning drugs, for example, warfarin, then the indicator can fluctuate normally from 2 to 3. All other indicators indicate violations in the clotting processes. Usually, an increase in INR indicates hypocoagulation, a decrease in INR indicates hypercoagulation. The causes of these syndromes have been noted above.

Preparation for a blood test for prothrombins

An analysis for prothrombins is given on an empty stomach. It is recommended that you do not eat for at least a period of time before the study. 8-9 hours. 10-12 days before taking the biomaterial - blood from a vein - you should stop taking medications, if possible. Otherwise, they can increase the clotting time. If it is impossible to stop taking medications, you need to inform the laboratory assistant about this. which will mark this data on the direction. It is also worth limiting the daily intake of fatty, fried, smoked foods and alcohol. In the morning on the day of the analysis, it is only allowed to drink clean still water.

The blood is placed in a test tube containing sodium citrate. It is gently stirred several times, tilted to the right and left, then placed in a centrifuge to separate the blood from the plasma.

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