Analysis for PTI: the norm. PTI: the norm in women

The prothrombin index (PTI) is one of the most important laboratory tests that characterizes the state of the coagulation system. It is expressed as a percentage. For various conditions, analysis is made for PTI. The norm in healthy people is 95-105%.

Blood coagulation is carried out in two directions - the internal and external pathways. The value of the PTI reflects exactly the external way of coagulation.

What is prothrombin?

The formation of blood clots and thrombi occurs under the influence of a special protein - thrombin, which under the influence of certain biochemical processes is converted from prothrombin. Thus, protein prothrombin is the second blood coagulation factor. It is synthesized with the participation of vitamin K in the liver.

Prothrombin index (according to Kviku) allows to determine prothrombin activity. This test is calculated as a percentage of the blood plasma values of the patient with the control sample. To monitor the operation of the blood coagulation system, a blood test is performed on the PTI. The norm in different laboratories may differ slightly, but these differences are not significant. They depend on the reagents the laboratory is working with. In some conditions, for example, with varicose veins, heart attacks or after heart surgery, the doctor sets the norm for patients, because In these cases it is necessary to achieve hypocoagulation of the blood (reducing its coagulability). This is done to prevent thrombosis.

Who is assigned to the analysis for PTI?

Usually, in the study of PTI, the norm in women is the same as for men. This indicator varies only during pregnancy, and there are a number of reasons for this, which we will talk about a little later. In what cases is a biochemical blood test given to a PTI? The norm of this study, for example, when taking indirect anticoagulants may be lower by half. Patients taking these drugs should regularly monitor RTI and INR. The research on PTI is mandatory in the following situations:

• Before any operations.
• People who take medications anticoagulants to prevent the formation of blood clots.
• Women in pregnancy.
• People suffering from diseases of the coagulation system, for example, with varicose veins.
• With autoimmune disorders.
• With atherosclerosis and heart diseases.
• With liver pathologies, for example, cirrhosis.
• With a deficiency of vitamin K.
• With antiphospholipid syndrome.
• For screening testing of a coagulation system.

During pregnancy, they must pass an analysis for PTI. The norm in women during pregnancy is slightly higher than that of other healthy people. This is due to a change in the hormonal background and the appearance of an additional utero-placental circle of circulation.

PTI in pregnancy: the norm

During pregnancy, all women are required to study the coagulogram. It includes:

1. PTI (prothrombin index).
2. INR (international normalized attitude).
3. APTTV (activated partial thromboplastin time).
4. Fibrinogen.

All these parameters are extremely important. Thus, the increase in PTI in the last pregnancy period to 150% and higher may indicate a risk of placental abruption. And with a drop in this indicator before births below 80% there is a risk of bleeding during labor or in the postpartum period. Thus, it is especially important to examine the coagulation system at the end of pregnancy. For this, the analysis of the PTI is taken. The rate of this indicator during pregnancy varies from 90 to 120%.

What does the increase in PTI indicate?

So, we found out that when the blood thickens, the value of the PTI increases. The norm of this indicator in healthy people ranges from 95 to 105%. An increase in the prothrombin index may indicate a risk of developing such diseases as:

• Myocardial infarction.
• Thromboembolism.
• Polycythemia.
• Oncological diseases.
• Detachment of the placenta in pregnant women.

What does the low level of PTI indicate?

In cases of taking anticoagulants, the level of PTI may drop to 45-40%. When the threat of blood clots, the dose of these drugs is controlled by a doctor. After increasing or decreasing the dose of the drug must be submitted to the analysis of PTI. The norm for such patients is determined by the attending physician. If the prothrombin index has not decreased with anticoagulant intake, this may indicate, for example, vitamin K deficiency, serious liver or gastrointestinal disease in general, and in pregnant women before birth, the risk of bleeding during labor.

What is INR?

This indicator is the standard for determining blood clotting. The value of INR reacts to the activity of certain blood proteins, which are coagulation factors. Such proteins are produced in the liver with the participation of vitamin K. These clotting factors react to the use of medications - indirect anticoagulants, for example, "Dabigatran", "Warfarina" or their analogues. In this case, hypocoagulation takes place, i.e. Blood coagulation is much slower. For some patients, this is vital, many of them are forced to take anticoagulants for life.

Analysis of blood PTI. INR: norm

In the coagulogram, in addition to the analysis of PTI, other indicators are of great importance. When appointing patients with indirect anticoagulants, RTI decreases. But for the analysis of PTI the norm in each laboratory may be slightly different, therefore a standardized test - MNO - was introduced. Doctors use it to control the blood coagulation system when taking patients with anticoagulants. Thus, INR in these cases is assigned in parallel with such an indicator as a blood test for PTI. The norm of INR in healthy people is from 0.8 to 1.2. With anticoagulant intake, coagulability decreases, hypocoagulation occurs, and INR may increase 2-3 times the normal, for example, in heart surgery or varicose veins to prevent blood clots. If the blood becomes thicker, its coagulability increases and, accordingly, the INR decreases.

Hypocoagulation. In what situations is it necessary?

In the analysis of RTI, the norm ranges from 95 to 100%, and the INR from 0.8 to 1.2. Let's remind, such norms should be at absolutely healthy people. But there are situations when the value of INR is vital to maintain on high figures, accordingly, the indicators of PTI will be below the norm, i.e. This will be the state of hypocoagulation. This condition is achieved by the reception of indirect anticoagulants. The dose of the drug can be determined only by a doctor. Patients who are constantly taking such medications, should regularly take a blood test for MNO.

• In the case of atrial fibrillation, the INR values should be maintained within 2.0-3.0.
• Severe condition - PE (pulmonary embolism) - also requires maintaining the level of INR within 2.0-3.0.
• After heart surgery, anticoagulants should be taken, while in the case of aortic valve replacement, INR numbers should be maintained within the appropriate range 2.0-3.0, and with mitral valve replacement at 2.5-3.5.
• With some defects in heart valves (mitral or aortic defect) and prevention of thromboembolism, the level of this indicator should be in the range 2.0-3.0.
• When treating venous thrombosis, INR numbers should correspond to 2.0-3.0.

When the INRs fall below acceptable limits, the dose of "Warfarin" or its analogues is increased. This is done solely under the supervision of a doctor and laboratory research. But increasing hypocoagulation (increasing INR values) above the allowable corridor can also have a negative impact on the health of patients. This is dangerous first of all with various bleedings. They can be either internal (uterine, gastric or intracavitary), and external, arising from various injuries or cuts. If the INR numbers are above the allowable limit indicated for a particular condition, the dose of anticoagulants should be reduced. Some patients control the level of INR for life.

How can I take a blood test for MNO and PTI?

Blood is spent on such examinations in the treatment room. Take venous blood in a test tube with an anticoagulant, in the role of which sodium citrate usually acts. The ratio between the blood taken and the anticoagulant should be 9: 1. The sample taken is well mixed by turning the tube to prevent clot formation. The blood is immediately sent to the laboratory. The analysis should be performed no later than two hours after blood sampling. Failure to comply with these conditions may distort the result of the analysis. Blood is usually given in the morning on an empty stomach, but if necessary, this analysis can be done at other times by cito, i.e. urgently.