Prothrombin (PT) is one of the indicators of the system, which is responsible for ensuring that blood clots normally, blood clots form, and in case of injury they stop bleeding.
PT is a very important test factor determined in the blood clotting test, which helps diagnose a wide range of diseases, as well as prevent in advance bleeding that is difficult to stop, or increased formation of blood clots.
This protein component is produced in the liver, it is also a thrombin precursor, which is directly involved in the formation of blood clots. Fixing the glycoprotein indicator is the main element under study when analyzing a hemostasiogram.
Prothrombin - what is it?
When a patient is admitted to the inpatient department, the next morning, blood is drawn for testing. general analysis blood, sugar and prothrombin levels. These studies are carried out as the main methods of description general condition patient, and determining the clinical picture.
Other blood tests, such as biochemistry, or coagulation tests, etc., can be performed on the day the patient is admitted if obvious symptoms appear and there is a suspicion of specific diseases, or, if there is a goal to explore in more detail individual organs, and to monitor the effectiveness of therapeutic agents.
One part of the blood clotting system is plasma proteins called clotting factors. There are thirteen factors in total, marked with Roman numerals from one to thirteen.
One of the most significant components is prothrombin (glycoprotein), which appears as a second blood clotting factor.
This coagulation factor is also called the prothrombin complex (prothrombinase), which belongs to alpha globulins, and is produced by liver cells.
The formation of prothrombin is influenced by vitamin K, due to the lack of which, the level of this protein is reduced. During a period of normal health, prothrombin does not show itself in the body, being activated only if the formation of a blood clot is necessary.
Normal levels of prothrombin protein indicate normal blood clotting, functioning effectively and timely restoration of blood in case of blood loss.
Prothrombin testing is performed less frequently than clinical analysis blood, since the procedure is very complex, and is prescribed if necessary. The main reasons for prescribing a prothrombin test are pathological conditions, in which blood clotting is impaired.
Normal indicators
A study aimed at establishing a quantitative indicator of prothrombin is quite complex, since this form of plasma protein breaks down quickly and easily. A blood test helps detect abnormal blood clotting (prothrombin test).
After which, based on the results of the coagulogram, more specific methods of blood testing are prescribed (INR, PTT and other methods).
To determine the functioning of the blood clotting system, there are several methods that are worth considering separately. Norm according to Kwik
This type of prothrombin study is the most common, and involves the calculation of prothrombin levels as a percentage of the normalized value. This indicator helps determine the activity of prothrombin in comparison with other dilutions of the patient’s plasma.
The Quick study is considered the most informative than prothrombin index(pti). After testing the blood for clotting speed, a schedule is drawn up based on the data obtained.
A blood test according to Quick is prescribed in the following cases:
- In case of malfunctions in blood clotting processes;
- An increased process of blood clot formation is recorded;
- For leukemia;
- With vitamin K deficiency.
Prothrombin complex levels fluctuate depending on age category study patient.
Normal indicators are recorded in the table below.
| Age group (years) | Normal prothrombin (%) |
|---|---|
| Less than 6 | 80 – 100 |
| 6 – 12 | 79 – 102 |
| 12 – 18 | 78 – 110 |
| 18 – 25 | 82 – 115 |
| 25 – 45 | 78 – 135 |
| 45 – 65 | 78 – 142 |
Gender has no effect on prothrombin levels; they are the same for men and women.
A decrease in prothrombin according to Quick occurs during therapy with indirect anticoagulants, and at the same time a high INR is recorded. It is necessary to take this into account and carry out therapy control analysis in the same laboratory and in the same way.
In other cases, you can get inaccurate results, which will negatively affect the adjustment of the course of therapy.
Prothrombin index
This indicator is indicated in %. If the prothrombin status is normal, the indicators of this analysis may coincide with the results of PT according to Quick. And if the prothrombin level is low, the values of these two tests differ significantly.
Also, the prothrombin index depends on the sensitivity of the chemical reagents used in the analysis.
This means that when different chemicals are used for research in different laboratories, the standards may vary depending on this sensitivity.
Normal index values are from ninety-five to one hundred and five percent.
High rates of PTI are recorded in the following diseases:
- DIC syndrome;
- Liver pathologies;
- Increased activity of factor VII (tissue death, injury);
- Triggering a protective reaction in women during childbirth;
- The formation of blood clots that clog blood vessels, subsequently leading to pathological conditions of the hematopoietic system;
- Excessive work of the anticoagulant system.
A decrease in these factors occurs with the following abnormalities in the body:
- Insufficient production of vitamin K;
- Taking a course of anticoagulants;
- DWS syndrome;
- Pathological conditions of the liver, with damage to hepatocytes;
- Congenital deficiency individual factors blood clotting (X, VII, V, II).
Prothrombin time (PTT)
This indicator is characterized by the clotting time of plasma after adding the research mixture to it. Allows for a quick assessment of homeostasis and determination of blood coagulation reactions.
In the event of situations dangerous to the body, such as traumatic situations with tissue damage, severe hemorrhages, tissue death and other pathological conditions of the body, a glycoprotein enters the blood, which is responsible for turning on the external homeostasis system, or, more simply, for tissue restoration.
Glycoprotein is also called tissue factor. Due to its entry into the blood, it reacts with plasma protein factors circulating in the blood, activating the formation of blood clots.
In the first stage of the reaction, prothrombin is converted into active thrombin, which is subsequently activated by fibrin secreted by the liver and promotes the release of plasma protein factors.
The final results vary depending on the age category.
The most acceptable average value is nine to twelve seconds.
The PTT indicator is increased in some pathological conditions of the body, which include:
- Pathological conditions of the liver;
- Low amount of synthesized vitamin K;
- Hemophilia B;
- Increase in the number of red blood cells;
- Pancreatic cancer;
- Increasing the blood's ability to dissolve clots;
- Myeloid metaplasia;
- An increase in antithrombin levels, which blocks thrombin, and other factors of the hemocoagulation system;
- Hemorrhagic lesions in infants;
- Disseminated intravascular coagulation (DIC) syndrome.
During this study, blood is taken, as with the Quick method, with sodium citrate. International normalized ratio (INR)
This method is used additionally and is used to monitor the results of tests for prothrombin. This examination method is recommended by the World Health Organization and other committees and international organizations.
This test helps determine the effectiveness of prescribed therapy with substances that reduce prothrombin levels and inhibit clotting processes - anticoagulants.
This group of drugs is used to prevent increased formation of blood clots and prevent possible complications.
Normal INR values are from 0.85 to 1.15.
For pathologies of the heart valves, blockage of veins with blood clots, or blockage pulmonary artery, the prothrombin indicator according to INR can reach 3, which is considered the norm when carrying out the treatment of the above-mentioned diseases.
Normal limits can expand to four and a half when treating arterial thrombosis.
What are the norms for pregnant women?
During the period of bearing a child, a woman’s body undergoes major hormonal changes, which lead to changes in blood composition. The prothrombin index in pregnant women ranges from ninety to one hundred and twenty.
The prothrombin index study can be carried out up to four times during pregnancy.
Analysis is especially important in the last three months of pregnancy, since there is a short period of time before birth, and monitoring of the dynamics of blood parameters is required.
When the prothrombin level increases to one hundred and fifty, placental abruption may occur.
And when it drops to ninety percent, severe blood loss is provoked during the process or after childbirth, which can lead to the death of the mother. What specific studies can complement the analysis?
In cases where the above research methods do not provide complete information, the homeostasis system can be expanded by prescribing an examination of quantitative indicators of platelet factors and plasma protein factors.
They are prescribed if prothrombin analysis reveals abnormalities in the coagulation system.
Based on its indicators, the following expanding laboratory tests may be prescribed:
- Activated partial thromboplastin time (aPTT);
- Soluble fibrin-monomer complex (SFMC);
- Fibrinogen study;
- Thrombin time is the period of time during which fibrinogen turns into fibrin.
Blood testing methods are not limited to those listed above; others can be used, depending on the patient’s individual parameters. Indications for the study
A doctor may order a prothrombin test if one of the following factors is present:
- Decreased functioning of liver enzymes;
- When registering a hemorrhage in a patient that stops for too long, which clearly indicates a violation of the blood clotting process;
- To monitor and adjust therapy with prolonged use of anticoagulants;
- In an autoimmune state of hypercoagulation caused by antiphospholipid antibodies, to clarify the factor that provoked the disease;
- For diseases of the body that are accompanied by a violation of the production of vitamin K by the human body;
- The test is often prescribed for women age group from fifty to sixty years, since at this time hormonal changes occur that change the composition of the blood.
Preparing for the test
After the patient has been prescribed a prothrombin test, some preparatory measures should be taken. They are followed in order to get the maximum exact result, since some third-party factors can affect the composition of the blood.
Actions that must be taken when preparing for a prothrombin test are:
- The analysis is done on an empty stomach. Eating must be stopped at least eight hours before donating blood. But last appointment food should not be more than fourteen hours old;
- At least one day before blood sampling, you need to stop eating fatty, highly salted, spicy or spicy foods;
- Give up alcoholic beverages at least 24 hours in advance;
- Sixty minutes before the test you need to stop using cigarettes;
- If the patient is taking medications, they must be stopped at least 48 hours before blood collection. If a person is undergoing treatment, or there are other reasons why the drug cannot be interrupted, the analysis should be postponed until the end of the course of therapy. If you continuously use drugs, you need to notify your doctor about this so that he takes into account all the corrections in the test results, which will contribute to an accurate diagnosis.
How is the analysis done?
A blood test for prothrombin begins with a blood sample venous blood(find out?) in the standard way.
Further research is carried out by placing sodium citrate in a test tube, after which the plasma is separated from the blood using a centrifuge.
Further research is carried out with the resulting plasma, adding different reagents and monitoring the behavior of the plasma on their effects.
Why are levels going down?
The prothrombin level is decreased or increased; it occurs either as an acquired factor during life or as a congenital factor. The latter is registered quite rarely, and is caused by mutation processes of recessive genes, which are localized on the eleventh chromosome.
With pathologically low content total number proteins in the blood, in most cases, the prothrombin level is also reduced.
The decline in PT indicates that even with the slightest damage to the vessel, large blood losses can be provoked, since coagulation and blood clot formation are reduced. In this case, blood loss stops much longer, and damage to human tissues (organs) heals more slowly.
At low levels of prothrombin, and even average open wounds, can cause loss of a large volume of blood, which can be fatal.
The main reasons influencing the decrease in this indicator are the following:
- Certain pathological conditions of the liver(in most cases, with liver diseases, protein increases). Death of liver tissue, as well as different shapes hepatitis have a detrimental effect on prothrombin, lowering its levels;
- Insufficient production of vitamin K by the body. In most recorded cases, this process is observed in pathologies gastrointestinal tract, and disruption of the composition of intestinal microorganisms (increase in the number of harmful bacteria);
- Lack of protein produced by the liver - fibrinogen in the body, which subsequently becomes fibrin, which is the main one for the formation of a blood clot during blood clotting;
- Oncological diseases;
- Allergic reactions;
- With an incorrect diet. If a person consumes a large amount of meat products, but few fresh fruits and vegetables, then the protein level decreases ;
- Use of certain medications, which reduce coagulability, thereby reducing the quantitative concentration of protein.
Reduction to normal prothrombin levels occurs after the administration of effective therapy. To do this, you need to be examined by your attending physician, and after the specialist examines the test results, he can prescribe the most effective therapy, so that prothrombin levels become higher.
Treatment of low prothrombin
Any therapeutic agents are prescribed exclusively by the attending physician. Most often, with low prothrombin, Heparin and Warfarin are prescribed, which are the most effective means to increase blood clotting.
A significant role in low levels prothrombin plays a role in proper nutrition.
First of all, it is necessary to limit as much as possible, or better yet exclude, next list products:
- Buckwheat;
- Bread in any form;
- Salty dishes;
- Smoked meats;
- Animal fats;
- Legumes;
- Red pepper, red cabbage, beets;
- Greenery.
IN preventive measures, along with the prescribed therapy, a diet is prescribed, which should include the following foods in the diet:
The use of such products will significantly accelerate the normalization of prothrombin levels.
Why do prothrombin values increase?
An increase in the levels of the prothrombin complex indicates that blood clotting is increased, and the chance of forming blood clots increases, which can subsequently block the vessels, leading to serious complications.
Especially if the vessels supplying vital organs are blocked, in which case there is a high risk of death.
When the vessels supplying the heart are blocked, death occurs in a matter of minutes.
With increased formation of blood clots, narrowed blood vessels pose a particular danger.
The reason for this may be deposits of atherosclerotic plaques, or pathological conditions of blood vessels. In this case, the chance of thrombosis of these vessels increases significantly.
Increased formation of blood clots can be provoked by:
- Tumor formations of a malignant nature;
- Pathological conditions of the liver;
- Thrombosis of blood vessels;
- The number of red blood cells in the blood volume is increased, which entails an increase in the amount of proteins, since the proteins themselves are located inside the red blood cells;
- Pathological condition of the heart, which is characterized by painful sensations V chest, also called "angina pectoris";
- Hereditary predisposition and other pathologies;
- Excessive amount of vitamin K in the human body;
- Use of Heparin, laxatives, Aspirin, Methotrexate, hormonal drugs, antibiotics, or nicotinic acid. Reception listed drugs, above the specified norm, will lead to an increase in prothrombin in human blood.
In most cases, an increase in prothrombin is recorded between the ages of forty-five and fifty years, regardless of gender. In women, an increase in the prothrombin complex can be provoked by the use of hormonal drugs.
High level treatment
In order to reduce increased level Prothrombin requires a certain diet and a more active lifestyle.
The following foods increase blood density:
- Food made from animals, such foods store a lot of cholesterol and fatty acids. It is not worth removing completely from the diet, but reducing consumption is possible. These do not include dairy products;
- Fried and smoked dishes;
- Food with increased content proteins;
- Fast carbohydrates (sugar, candy, bars, cakes, pastries, potatoes);
- Alcoholic drinks and soda;
- Bananas;
- Strong tea and coffee.
Certain types of herbs also affect increased clotting:
- Fresh nettle;
- Yarrow;
- Burdock;
- Needles;
- Burnet.
You should not sharply limit the consumption of the above products, as some of them also contain useful components. You should only gradually reduce their presence in the diet.
Effective products for reducing prothrombin in the blood are the following:
The most frequently prescribed medications include:
- Aspirin, Magnicor, Cardiomagnyl, Dipyridamole are drugs containing aspirin, which thins the blood. But drugs are not always prescribed, when the following diseases their acceptance is prohibited:
- Hypertension;
- Bronchial asthma;
- Pregnancy;
- Stomach and intestinal ulcers;
- If you are allergic to the components of these drugs.
- If such diseases are detected, then other drugs are prescribed:
- Neodicoumarin;
- Warfarin;
- Heparin.
Preventive actions
In order for the prothrombin level to be within normal limits, it is recommended to follow preventive actions aimed at wide range diseases:
This list of actions is aimed at prevention large quantity diseases, and will help minimize the chance of damage to the body.
Forecast and conclusion
An excessive decrease in the quantitative indicator of prothrombin indicates too liquid blood, with a lack of protein components. In case of injury or childbirth, this can lead to large blood losses, which can be fatal.
Insufficient protein saturation will lead to progression individual pathologies. A large increase in prothrombin levels leads to increased formation of blood clots.
In this case, there is a high chance of blockage of blood vessels. This condition always threatens human life.
When blood vessels are blocked, it is vital important organs may result in very rapid death. When overlapping coronary arteries heart, or blockage of other arteries of the heart, death occurs almost immediately and unexpectedly.
Thanks to a wide selection like medicines, and means available to everyone traditional medicine, and just food products, support normal condition blood is not difficult.
Everyone is able to choose an option that suits them personally. When selecting medications and diets to maintain normal prothrombin, it is best to consult a doctor in order to avoid incorrectly combined treatment.
Those who are interested in the prothrombin index should know that the norm in women is in the range of 78-146%.
The blood coagulation system consists of 15 factors. Its condition is characterized using various indicators. Prothrombin is an active protein of the blood coagulation system that stimulates the formation of a blood clot.
To assess the state of the blood coagulation system, a prothrombin test in the blood is prescribed. When deciphering the result, you can get a high or low value of the prothrombin index. The protein in question is produced (in the liver) by vitamin K. Using prothrombin time and prothrombin, the doctor assesses the condition of the gastrointestinal tract and liver.
The procedure is carried out on an empty stomach. Blood is taken from a vein. Tissue thromboplastin is added to the material.
If the patient has just started taking anticoagulants, then frequent blood tests will be required (abnormalities may occur). The doctor must select the appropriate remedy and adjust the dosage. Then a repeat study is carried out.
Initially, the patient donates blood once every 2 days, and then 2-4 times a month. The prothrombin time value will allow you to calculate the period required for the formation of a blood clot (after adding reagents). The prothrombin time rate is multiplied by the thromboplastin sensitivity index indicated on the reagent packaging. The higher the value, the greater the blood clotting.
Thinning agents are taken at the same time. The analysis is carried out in a laboratory or at home. In the latter case use special device. A blood test for protein content allows you to obtain the following indicators:
- Prothrombin time - the value is indicated in seconds (the patient's blood clotting time).
- Prothrombin according to Quick - shows the activity of prothrombin in the patient’s blood plasma. A calibration schedule is prepared in advance. In this case, prothrombin time is taken into account. The value of the indicator is expressed as a percentage.
- Prothrombin index (the ratio of prothrombin time is normal to that of the patient).
- INR (helps assess the effectiveness of therapy).
Symptoms
If the prothrombin index is studied, the norm ideally in men and women can range from 95-105%. Prothrombin according to Quick normally does not exceed 142%. If these indicators are normal, then their values coincide. The result of the test for the presence of prothrombin in the blood is issued on a form. The normal prothrombin time is 9-12.6 seconds, and the INR is 0.85-1.15. If the prothrombin level is below the average level, then bleeding can be caused by the following factors:
- taking medications that cause decreased clotting;
- vitamin K deficiency;
- nephrotic syndrome;
- disturbances in liver function.
If the above diseases appear during pregnancy, then you will need urgent help doctor. If the prothrombin index rate exceeds the average value, then increased coagulability blood. This condition can be caused by the following factors:
- presence of heparin;
- excess vitamin K;
- long-term use of hormonal contraceptives.
This symptom manifests itself in the following diseases:
- thromboembolism;
- heart attack;
- the presence of a malignant tumor;
- high level of red blood cells.
The value of prothrombin and prothrombin time is important during pregnancy and when planning it. A coagulogram is prescribed to expectant mothers, since with this indicator it is possible to prevent bleeding during childbirth and the formation of a blood clot.
If the value is low, then there is a risk of bleeding. In this case, the patient is prescribed coagulants. Otherwise, pregnant women are prescribed medications that prevent increased blood clotting. Before childbirth, the obstetrician-gynecologist must know the level of prothrombin time. The value of this indicator will allow the doctor to prevent hemolytic shock during natural and artificial childbirth. If the obstetrician-gynecologist is not aware of the low value of the prothrombin index, then he will not be able to prevent placental abruption. Lack of prothrombin contributes to the manifestation of the following symptoms:
- prolonged bleeding;
- heavy blood loss.
In this case, it is violated physiological system human body.
Index excess and deficiency
If the prothrombin index value is high, then the doctor will be able to promptly prevent the development of thrombosis. High content prothrombin in the blood can provoke atherosclerosis. Doctors recommend regularly monitoring this indicator.
To normalize prothrombin levels, you must follow special diet. The patient should drink plenty of fluids (juice, soup, water). It is useful to include fresh vegetables and fruits in your diet. It is not recommended to overuse herbs that promote blood clotting (nettle, plantain, cudweed). If you adhere to such a diet, then prothrombin will be normal, and the risk possible bleeding and high blood clotting will be reduced to a minimum value.
Since protein is easily susceptible to the action of anticoagulants (Warfarin), it is therefore recommended to periodically test the blood for INR (especially when using anticoagulants).
The study in question is carried out in certain cases. Moreover, each indication is characterized by different standards of characteristics:
- examination of the patient before surgical intervention(INR ranges from 0.85-1.25);
- during treatment venous thrombosis and after surgery the value of the indicator does not exceed 2.0-3.0;
- for heart diseases and vascular system the indicator fluctuates between 3.0-4.5.
If the INR value exceeds 1.25, then there is a risk of developing the following pathologies:
- congenital diseases of the blood clotting system;
- liver diseases;
- the absorption of fats in the intestine is impaired;
- bile does not pass well from the liver into the duodenum.
Coagulogram in children
If the INR value exceeds 6.0, then urgent hospitalization of the patient is required. Otherwise, bleeding may occur. This condition is dangerous for a person in the presence of concomitant diseases such as inflammation and ulcers of the intestines and stomach, arterial hypertension, kidney disease. Vitamin K deficiency can be congenital. A similar phenomenon is often observed during pregnancy and after childbirth. During pregnancy, the normal thrombosis time is 11-18 seconds. The risk group includes women in a position with a high probability of miscarriage, uterine hypertonicity, and the presence of gestational symptoms. Prothrombin levels, the norm in pregnant women, range from 78-142%.
Normally, a child’s blood clots within 4-9 minutes. A coagulogram is prescribed to children in the following cases:
- operation;
- frequent bleeding;
- hemophilia.
The doctor checks the data obtained with the norm, taking into account the patient’s age and complaints. By using this study doctors can identify inflammatory, vascular and autoimmune diseases.
Timely diagnosis helps to detect the disease in time. That's why it's so important to pay attention to symptoms. As a method early diagnosis A prothrombin blood test is used. Its non-compliance with the norm indicates a number of deviations. If ignored or untimely prescribed treatment, deviation of this indicator can lead to serious consequences.
What is prothrombin index
Description
The role of prothrombin in the blood is significant, because this protein compound is involved in blood clotting.
This component is produced in the liver area, in the blood it is an inactive compound.
During vessel damage, coagulation occurs. When the active form of prothrombin is taken, it gradually turns into thrombin. This component is the basis for the formation of blood clots.
When taking the analysis, not only the norm of this indicator is determined, but also others, their deviations become noticeable. Blood factors have 13 components. Each of them performs its own functional work. Among them, prothrombin occupies one of the most important places, in particular, its order is second in the table.
Important! For normal functionality of the body, all organs and cells must receive oxygen in the required quantities, as well as nutritional components. With the help of blood and its circulation through the vessels, this process is successful.
Indicator norm
This type of diagnosis is quite complex. Due to the rate at which molecular particles decay, it is difficult to determine their exact number. IN medical practices use the Kwik indicator. It is compared to the clotting time healthy person.
Diagnostic methods
Based on the results of this comparison, experts consider increased or decreased prothrombin. For calculation exact value use percentages. It has been scientifically proven that normal level prothrombin for a healthy person is 70 - 120%.
When calculating the indicator according to Kwik, which is complex procedure, define other values. With its help, specialists can assess the level of prothrombin index, time, and INR. A comprehensive assessment helps to make an accurate diagnosis and fully evaluate the blood clotting process.
Important! Decoding is enough complex process which should be dealt with by a specialist.
It is worth noting that normal indicator has the same meaning for males and females.
- According to the table, certain limits of normal prothrombin levels are distinguished. In particular, for a child under 6 years of age, this is 80–100%.
- Up to 12 years of age, the normal protein level is 79–102%. Before reaching adulthood, this value increases to 78 – 110%. An indicator of 82–115% is considered the norm for a person aged 18–25 years.
- 78–135% is typical for a person aged 25–49 years. Up to 60 years of age, the normal prothrombin level is 78–142%.
Attention! Prothrombin is quite complex in its characteristics. Its disturbances affect the formation of blood clots.
Purpose
It is worth noting that not everyone is prescribed a prothrombin test. This category of people includes those who need accurate diagnosis in the area of blood clotting. Most often, the analysis is prescribed to pregnant women, patients before surgical intervention surgically.
Correct interpretation of the analysis by a specialist allows you to identify dangerous deviations, which will protect human life. If this is not done, blood loss may occur during the operation.
Prothrombin levels are of significant importance during pregnancy. Experts recommend that women in pregnancy undergo the test procedure every month. Thus, the doctor constantly regulates the state of the body and the level of coagulation. If deviations are identified, he takes the necessary measures.
Role of Prothrombin
When considering pregnancy, it is worth considering the changes characteristic of this condition. In particular, in the first half, prothrombin is in a reduced state, which is considered normal. The deviation is explained by the fact that the body feels a lack of vitamin complex, is gradually being rebuilt.
Towards the end of pregnancy, normalization of these indicators is observed. There are cases of increased values before the birth of the baby. This deviation requires adjustments to minimize the occurrence of complications.
Attention! A woman must undergo this test during pregnancy.
With its help, it is possible to determine in time possible deviations, make adjustments without harming the health of both mother and baby.
Experts identify several categories of people for whom this procedure needed on a regular basis. These are patients who have poor blood clotting. For liver diseases, or those that affect vitamin K, this procedure is prescribed. Regular testing is necessary to check prothrombin levels. During treatment with anticoagulants, this indicator is given special importance.
Increased performance
This trend can be observed in the presence of:
- oncological diseases. It is known that cancer cells have a detrimental effect on the production of protein components. In its entirety, it affects the process of blood clotting;
- liver diseases, both chronic and acute. The liver is the organ in which the component is produced. During normal functional operation of one, similar indicators of the other element are observed;
- a pathological change is possible with polycythemia. This disease develops due to heightened state red blood cells This process is dangerous due to a series of thrombosis and bleeding;
- against the background of increased prothrombin levels, thromboembolism occurs. A disease of this type manifests itself in the form of a blood clot;
- Deviation from the norm is also affected by medication use. Among side effects highlight the increase in value. It is important to read the instructions, be sure to consult a doctor, and inform about all groups of medications that you are taking.
Increased performance
Decreased performance
This situation may be accompanied by bleeding, which poses a threat to human life. Among the pathologies that affect this process are:
- with hepatitis or cirrhosis of the liver, the organ is not able to perform its functions normally functional responsibilities. All this directly affects the process of blood clotting;
- in case of use of anticoagulants;
- Vitamin K is synthesized in the gastrointestinal tract. With dysbacteriosis or diseases in this area, there is a deficiency in vitamin production and a decrease in prothrombin levels;
- insufficient fibrinogen synthesis affects the deviation of the indicator.
Decreased performance
conclusions
It is important to seek help from a doctor in time. It is enough to monitor the quality of your health and pay attention to symptoms that are uncharacteristic for you. In particular, with prolonged bleeding of the gums, nose, or the appearance of bruises for no specific reason, conclusions are drawn about a reduced prothrombin level.
When taking the test, the specialist assesses the state of health, indicates possible reasons deviations. Based on all this, only he can appoint effective course treatment.
It was developed in 1935 by American physician and researcher Armand James Quick. Much later, in the 80s of the 20th century, a calculated INR indicator was proposed to take into account the results of PT in patients receiving indirect anticoagulants. The ability to effectively control the action of indirect anticoagulants, primarily warfarin, has led to the demand and widespread use of this coagulation technique.
Principle of the method
PT is based on determining the coagulation time after adding thromboplastin to BTP. The latter is a procoagulant substance biological origin containing phospholipids and tissue factor. Induction of coagulation in the PT occurs due to the activation of proconvertin by tissue factor in the presence of phospholipids and Ca ++ ions.
Reagents and equipment
- Thromboplastin-calcium reagent.
- Physiological 0.9% sodium chloride solution (used for diluting BTP samples when studying prothrombin activity according to Quick).
- A sample of a normal FTP.
- Coagulometer (if there is no coagulometer - water bath and stopwatch).
Blood samples for research To determine PT, BTP is used. Features of the preparation of BTP samples are discussed in detail in Appendix 3.
Evaluation of the study results
Normal PT values are usually indicated by the manufacturer of the thromboplastin-calcium reagent, but this information should be used only as an approximate estimate of the normal range, since the results of the test depend on the technique used, the batch of the reagent, and many other factors. To more effectively evaluate the results of PT, it is customary to use calculated indicators(PO, MHO, etc.), based on the results of determination of PT in the test and control (normal) samples.
Prothrombin ratio (PR).
To calculate software use the following formula:
PT = PT(b) / PT(k), where PT(b) is the patient’s prothrombin time, PT(k) is the prothrombin time of a normal BTP.
The software does not take into account the ability of thromboplastins to interact differently with decarboxylated coagulation factors (PIVKA), so this indicator is only suitable for screening assessment of the external coagulation mechanism in patients not receiving indirect anticoagulants (with cirrhosis, disseminated intravascular coagulation syndrome, etc.). In contrast to the PT, the inter-run variation of thromboplastin does not have a significant effect on the results of calculating the PT.
Normally, software does not exceed 1.3. A decrease in this indicator to less than 0.8 often indicates defects in the preanalytical stage of the study or an error in measuring the PV of a sample of normal BTP.
International normalized ratio.
It is known that the hypocoagulative effect of indirect anticoagulants is based on the inhibition of vitamin K epoxide reductase (VKOR), which regulates the ability of glutamyl carboxylase to carboxylate factors of the prothrombin complex (II, VII, IX and X) and physiological anticoagulants (proteins C and S).
Prescribing indirect anticoagulants to a patient naturally disrupts the external coagulation pathway, however, the degree of prolongation of PT significantly depends on the thromboplastin used. The calculated MHO indicator, adopted in 1983 by the WHO Committee for Standardization in Hematology, is intended to standardize the results of determining PT in patients receiving indirect anticoagulants. To calculate it, information about thromboplastin MIC is required.
MHO = (PO)mich, where PO is the prothrombin ratio, MICH is the international thromboplastin sensitivity index.
It is not customary to indicate the normal range of the MHO indicator, since this indicator is intended primarily for patients taking indirect anticoagulants. The therapeutic MHO interval for most clinical situations related to the need to prevent thrombotic disorders with indirect anticoagulants is in the range of 2-3. However, in some situations this range should be different. A decrease in this indicator to less than 0.8 often indicates defects in the preanalytical stage of the study or an error in measuring the PV of a sample of normal BTP.
Prothrombin activity index according to Quick.
Another test option is the determination of prothrombin activity according to Quick. The technique for determining this indicator does not differ from that when assessing PO and MHO, however, it is additionally necessary to measure PO in diluted samples of normal PRP. The results are obtained using a calibration graph reflecting the dependence of the coagulation time of normal BTP on the degree of its dilution. The prothrombin activity of undiluted normal pooled plasma is assessed as 100%, the clotting time of the same plasma, diluted 2 times, as 50%, 4 times - 25%, 8 times - 12.5%.
Prothrombin activity of plasma according to Quick is not considered a standardized indicator, therefore the results of the determination differ when using different thromboplastins. This indicator is suitable for assessing the external coagulation pathway in patients who do not receive indirect anticoagulants (with cirrhosis, disseminated intravascular coagulation syndrome, etc.).
In healthy individuals, the Quick index of plasma prothrombin activity depends on the type of thromboplastin used, the equipment used and other factors, so for each laboratory it is advisable to clarify the local normal range. An increase in this indicator by more than 120% often indicates defects in the preanalytical stage of the study or an error in measuring the PT of a sample of normal PCP.
Prothrombin index.
The prothrombin index is an outdated way of assessing the results of PT accounting. This indicator should not be used at this time.
Interpretation of research results
PT is one of the basic methods for studying coagulation hemostasis. Prolongation of PT (increased PO, MHO, decreased prothrombin activity according to Quick) is observed with low activity or functional inferiority of the following coagulation factors: VII, V, X, II and fibrinogen. That is why PT in patients with liver diseases and biliary tract often reveals dysfunction of the external coagulation mechanism. In addition, in the presence of inhibitors in the blood, consumption coagulopathy and the use of direct anticoagulants, this test also shows pathological values.
Congenital deficiencies of Stewart-Prower factor and prothrombin, as well as hypoproconvertinemia, vitamin K deficiency, hypo-, dys- and afibrinogenemia in clinical practice are very rare, but their existence should always be remembered when detecting an extended PT in a patient with hemorrhagic syndrome And normal function liver.
During treatment recombinant factor Vila, a significant shortening of PV occurs.
Standardization of PT is currently carried out on the basis of the results of determining PT in plasma samples containing PIVKA factors and calculating the thromboplastin MIC, therefore more or less reproducible results are obtained only when using the MHO indicator in patients using indirect anticoagulants. Unfortunately, in case of coagulopathies caused by insufficiency of coagulation factors I, I, V, VII, X, diseases of the liver and biliary tract, PT when using thromboplastins from different manufacturers (even when calculating MHO) varies significantly.
Causes of errors
- Heparin from a venous catheter enters the test blood.
- Hemolysis.
- The use of the so-called prothrombin index and non-standardized thromboplastins causes gross errors in the interpretation of PT.
- Lack or ineffectiveness of the internal quality control system.
- The simultaneous use of different indicators for assessing the results of PT (for example, MHO and plasma prothrombin activity according to Quick) in patients receiving indirect anticoagulants naturally leads to confusion in assessing the results. To monitor treatment with indirect anticoagulants, a mandatory and undiscussed requirement is the calculation of the MHO indicator.
Other analytical technologies
To determine PT, various thromboplastins are used. These reagents differ significantly in their preparation technology, source of raw materials (rabbit brain, placenta, etc.), as well as in their ability to detect various defects in the external coagulation mechanism.
Another option for PT is the study of plasma according to Ouren. To implement this option for assessing the external coagulation pathway, coagulation factor V and fibrinogen are additionally added to the reagent, which eliminates the influence of these two components of the coagulation cascade on the results of PT.
Some special coagulometers implement technologies for determining the MHO indicator, based on the use of dry chemistry methods (INR detectors).
To detect the effects of lupus-type inhibitors, it is advisable to use diluted thromboplastin, which can coagulate normal PTP in 40-45 s.
What kind of analysis is this?
Prothrombin- difficult protein, one of the most important indicatorscoagulograms, characterizing the state coagulation systemblood. Prothrombin or blood clotting factor II is a precursor to thrombin (a protein that stimulates blood clot formation).
Prothrombin is synthesized in liver starring vitamin K. Based on prothrombin analysis doctor can evaluate the performance and identify liver diseases and gastrointestinal tract.
For characteristics hemostasis systems(blood coagulation system) blood prothrombin analysis is the most important test included in hemostasiogram.
Why is the analysis carried out?
The results of the prothrombin blood test can be presented in various forms:
- Prothrombin time Reflects the clotting time of blood plasma, expressed in seconds.
- Prothrombin according to Quick A. Quik proposed this test in 1935 to analyze blood clotting by determining the level of prothrombin. The assay displays the percentage of prothrombin activity as determined by a calibration graph generated by measuring the prothrombin time in diluted solutions of normal plasma. Today, this test is the most popular method for analyzing prothrombin.
- Prothrombin index(or prothrombin index)The definition of the prothrombin index expresses the ratio of the prothrombin time of a healthy person to the prothrombin time of a patient. Expressed as a percentage.
- International normalized ratio (INR)
INR analysis is recommended by the WHO expert committee, the International Committee on Thrombosis and Hemostasis and the International Committee for Standardization in Hematology for monitoring during treatment with indirect anticoagulants. Indirect anticoagulants- these are synthetic substances similar in structure to vitamin K, which reduce prothrombin in the blood and slow down blood clotting. Anticoagulants are used in the treatment of diseases associated with the formation of blood clots in veins- in treatment thrombophlebitis, thrombosis, pulmonaryembolism, thromboembolic complications with myocardial infarction, coronary insufficiency . The INR blood test allows the doctor to monitor the effectiveness of the effect. drug therapy for these diseases.
Increased prothrombin- symptom of the following diseases:
- thromboembolism
- myocardial infarction, pre-infarction condition
- polycythemia
- malignant tumors.
Low prothrombin in the blood gives the doctor reason to make the following diagnosis:
- congenital or acquired prothrombin deficiency
- lack of vitamin K.
Results/Normal/Transcript of analysis
Prothrombin norms: 78 - 142% (Kwik blood prothrombin analysis).
Prothrombin index - analysis and interpretation of its results
What does your prothrombin index indicate? The analysis and its results are issued in the laboratory on a form that contains normal indicators. Let's list them here:
- prothrombin time is normally 9-12.6 seconds;
- low prothrombin index – less than 77%; that the prothrombin index is increased is indicated by an indicator exceeding 120%;
- The normal INR is 0.85-1.15;
- The prothrombin index of blood, calculated using the Quick method, is normally 78-142%.
In addition to the norm of the “prothrombin index” indicator, it is important to know what threatens a person with a decrease in the prothrombin index, or why this indicator is increased.
So, if the prothrombin index is reduced, this may indicate vitamin K deficiency, acquired or congenital deficiency of the prothrombin protein.
If prothrombin levels are higher than normal, there is reason to suspect a threat of heart attack, heart attack, thromboembolism, the presence malignant neoplasms, polycythemia (increased red blood cell count).
As you can see, blood tests for the content of prothrombin protein are important both for a pregnant woman and for one who is just planning a pregnancy. Be attentive to yourself, learn to trust the supervising doctor, this is the only way to avoid unwanted consequences during childbirth and complications after them.
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