Coagulogram - what is it? Decoding of blood coagulogram: indicators and norm

"Coagulogram - what is this?" - Surprised ask patients who are sent to take such an analysis. And indeed, the townsfolk encounter such a study infrequently, usually in the course of preparing for a planned operation. I know this term and all pregnant women. Analysis of the coagulogram in the process of bearing a child is done every trimester.

Under an incomprehensible word lies the study of blood coagulability. The set of indicators studied can vary depending on the specific laboratory. The analysis is indicative and detailed. In the first case, only the fact in which the link of the process of coagulation was directly affected is determined. A coagulogram is a detailed research, which, besides qualitative ones, also studies quantitative defects. With its help, it is possible to detect platelet abnormalities, various thrombophlebias, a deficit of certain clotting factors, and so on.

The totality of the methods used to obtain the result depends on the clinical picture, the type of pathology, the objectives of the analysis. It should be noted that deciphering the blood coagulogram is a great difficulty not only for the layman, but sometimes for the doctor. Usually, in order to make an accurate diagnosis, several correctly selected tests are required.

The process of blood coagulation

Let us consider in more detail how the coagulating system functions. At the first stage, with chemical or mechanical damage to the walls of the vessels, thromboplastin is released - a special substance that triggers the clotting reactions. Then, activation of coagulation factors - specific proteins, which are always present in the blood and ensure the formation of thrombus at the site of damage to the vessel wall - occurs.

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

Coagulation study in pregnant women

As already noted, each trimester, and in some cases and more often, a pregnant woman is given a coagulogram. What this is and why it is needed, future mothers know firsthand. The fact is that during the carrying out of the baby the activity of the coagulating system as a whole rises. This is a natural process, connected with the fact that there is a uterine-placental circle of circulation of blood. The organism of the expectant mother thus prepares for possible blood loss during childbirth.

A coagulogram is made to reveal the peculiarities of clotting disorders and some complications of pregnancy. The doctor can ask for an analysis at an unplanned time if there are deviations from the norm of parameters of hemostasis (components of blood and blood vessels, the interaction of which allows maintaining the integrity of the vascular walls and stopping bleeding in case of damage). Blood for examination is taken in the morning on an empty stomach from a vein.

Decoding of blood coagulogram

The analysis of the results of the analysis should be handled only by a specialist. Without special knowledge, a person can not decipher the coagulogram indices and assess the degree of their deviation from the normative values. Let's try to understand the intricacies of the process and tell you about the main parameters of the study.

1. Fibrinogen

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

2. Activated partial thromboplastin time (APTT)

The coagulogram examines the time for which a blood clot forms after the calcium chloride and other substances are connected to the plasma. If at least one coagulation factor is below the norm by 30-40 percent, the APTT level will change. On average, the norm is 30-40 seconds. Time can increase with a lack of vitamin K, liver disease. The cause of an increase in the duration of APTT and, as a consequence, a decrease in coagulation may be haemophilia.

3. Lupus anticoagulant

This parameter always contains a coagulogram. What is this indicator? Now tell. These are antibodies IgC and IgM, which increase the APTT. Normally, they should not be developed in pregnant women. Appear antibodies in the case of autoimmune diseases, with gestosis. Pregnancy against this pathology often results in spontaneous abortion, fetal death or a placenta infarction.

4. Prothrombin

It is a complex protein, it is a precursor of thrombin (a protein that stimulates the formation of thrombi). This is one of the most important indicators of a coagulogram. Prothrombin with the participation of vitamin K is synthesized in the liver. Analyzing the value of this parameter, the doctor can reveal the pathology of the gastrointestinal tract and liver.

5. Prothrombin time

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

6. Prothrombin index (PTI)

Coagulogram most often includes this parameter, instead of the previous one. This is the ratio of the clotting time of a healthy person's plasma and the patient's plasma, expressed as a percentage. Normally, the prothrombin index should fluctuate within 93-107 percent. Factors of this indicator are synthesized in hepatic cells, in liver diseases their number decreases, so the PTI can to some extent serve as a parameter for determining the functional state of the organ.

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

7. Thrombin time

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

8. Antithrombin III

It is a thrombin inhibitor, an anti-coagulant protein. It has a depressing effect on the processes of coagulation. The level of the indicator is determined by binding in a control sample of thrombin (by inhibition). The normal value of antithrombin III is 71-115 percent. Reducing the parameter by 50 percent of the norm leads to a risk of thrombosis.

The definition of this indicator is especially important for expectant mothers taking anticoagulants. These drugs are used when carrying a child, when blood coagulability is increased, and there is a threat of formation of placental insufficiency, termination of pregnancy.

9. D-dimer

This is an important indicator for the diagnosis of thrombosis, which includes a coagulogram. What does this parameter show? It allows to reveal the processes of thrombus formation and dissolution of fibrin. Normally, the D-dimer is less than 248 ng / ml. The level of the indicator begins to grow gradually in the early stages of pregnancy. By birth, the value of the parameter can exceed the original value by three to four times. This is considered the norm. A higher rate is found in women who have a complicated course of pregnancy (gestosis), as well as those who suffer from kidney disease, diabetes.

10. Thrombocytes

It is involved in providing hemostasis blood platelets. They are formed in the bone marrow. The normative value is 150-400 thousand / μl. In some cases in healthy women, a decrease in the number of platelets to 130 thousand / μl can be observed. A significant reduction in the number of these blood elements is called "thrombocytopenia" and results from a decrease in the formation of blood platelets, an increase in their consumption or destruction. With insufficient nutrition, platelet formation decreases. With DIC-syndrome, which will be discussed below, the consumption of the described formed blood cells increases.

11. DIC-Syndrome

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

12. Antiphospholipid syndrome (APS)

It is a complex of symptoms characterizing thromboses (venous and arterial). Women with ASF have a high risk of miscarriage and the occurrence of spontaneous abortion, because in this case the increase in the number of vessels of the placenta is broken, and fetoplacental insufficiency develops. To diagnose antiphospholipid syndrome, in addition to increased thrombosis, antibodies to the outer membrane membrane (phospholipids) are also detected.

Finally

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