Hemostasis - what is it? Hemostasis disorder

Many of us had to take tests for hemostasis. What is it and why should it be checked? The answer to this question should begin with an explanation of what our circulatory system is and what mechanisms work in it.

The first function of hemostasis

Few people know that our blood is also a tissue, only a liquid one. It consists of a plasma, which is actually its liquid element, as well as erythrocytes, leukocytes and platelets, which are in the plasma as if in a suspended state. All this continuously moves through large and small arteries, veins and capillaries, delivering oxygen, food and performing a host of other functions to the cells. Such is the simplified model of our circulatory system. It is very important that the blood has the right consistency. If it is too thick, clots form. If, on the contrary, it is too liquid, a person suffers from excessive bleeding. Preserves our blood in an optimal state created by nature system, called hemostasis. What is this system and what is the mechanism of its operation?

The second function of hemostasis

The system of hemostasis is very complicated. In addition to maintaining the proper viscosity and fluidity in the blood, it provides healing of wounds (stops bleeding) with cuts and other vascular injuries. The walls of the latter are formed by three layers of living tissue, each of which performs its role to ensure the uninterrupted passage of blood through the body. If, for any reason, the integrity of the vessel wall is disturbed, the blood rushes into the gap and the person is bleeding. To stop it, the body starts a system of blood clotting, or hemostasis. It can be of two types - primary and secondary.

Primary hemostasis: what is it

This type of cessation of bleeding is also called vascular-platelet hemostasis. The mechanism of his work is to cause a spasm of the damaged vessel, its narrowing and plugging of the "rupture" with platelets. On the damaged area a crust is formed, the bleeding stops. People say "the blood curdled." Those who do not have problems with hemostasis, this process takes up to 3 minutes. The mechanism of its action is as follows. On the walls of the vessel near the wound begins adhesion, that is, subsidence, adherence of platelets. Their shape becomes more rounded, and on the surface appear spines and processes that provide a strong bond with other platelets. As a result, they are glued together (aggregation), and a platelet is formed from the platelets. In 1 μl of blood should be from 150 to 300 thousand healthy platelets of the correct form. Otherwise, the process of clotting is disrupted.

What is secondary hemostasis?

Bonded platelets begin to release into the blood active biological and chemical substances that cause constriction of the walls of the vessel and the formation of secondary, irreversible gluing. Simultaneously with platelet factors, the most important clotting enzyme thrombin is released, which in turn affects the formation of fibrin protein. The fibers of this protein are the basis of the thrombus. They create, as it were, a network in which red blood cells and leukocytes become entangled. Fibrin is obtained from another protein - fibrinogen. To determine its amount in the blood, donate blood for hemostasis. What is it - fibrinogen - and what is its importance? This protein plays a leading role in blood coagulability. Its excess causes thrombosis, and the blemish is hemorrhage. The norm is from 1.5 to 3.0 g / L of fibrinogen. If it is more than 4.5 g / l, a person may have diseases such as tuberculosis, stroke, heart attack, malignant tumors, pneumonia, influenza and a number of other conditions, including severe burns, surgical operations, and the taking of certain medicines. The amount of protein less than 1.5 g / l causes liver cirrhosis, DIC-syndrome, hepatitis, myeloleukemia, toxicosis, cesarean delivery, polycythemia, snake bites, vitamin B12 and C deficiency.

The third function of hemostasis

The final stage of wound healing is fibrinolysis, for which hemostasis also responds. What it is? Fibrinolysis consists in the destruction of the obstructive thrombus and the restoration of blood circulation in a damaged blood vessel. From the first seconds of the wound healing process and the beginning of coagulability of blood in the plasma, the plasminogen enzyme is activated. It produces a protein called plasmin, which cleaves fibrin, and together with it a thrombus. Between the formation of thrombus and its dissolution should be a balance, which provides hemostasis. As you can see, this system is very complicated. Failure, even in the smallest of its links, leads to disruption of the whole chain and serious diseases.

Violation of hemostasis. What is it and how to identify it

Distinguish the following violations:

- increased blood coagulability (hypercoagulability), which leads to spontaneous formation of thrombi in the arteries, veins and internal organs. It is fraught with severe conditions, such as a stroke at a young age, frequent miscarriages in women, brain diseases (caused by thrombosis in the arteries of the brain) and others.

- decreased blood clotting (hypocoagulation), leading to spontaneous bleeding. It is observed in hemophilia, Willebrand's disease, platelet deficiency in the blood or their pathological changes, liver diseases, coagulation factor deficiency, thrombocytopathy.

- DIC-syndrome, in which both types of coagulation are present.

To determine the cause of abnormalities in blood clotting, conduct a haemostasiogram (coagulogram), or an analysis for hemostasis. What it is? This analysis is carried out by pregnant women, patients before surgery, people suffering from heart and vascular disease, as well as patients with pathologies of blood coagulability. Coagulogram is the base, in which hematocrit, hemoglobin, the number of all blood factors and a number of other parameters are determined. The second type of coagulogram is an enlarged one, which is prescribed mainly to people with pathologies of blood and pregnant women.

Hormonal hemostasis as a method of treatment

In some women, menstrual irregularities occur , expressed in abundant prolonged bleeding. To eliminate the problem, hormonal hemostasis is used. What it is? The method is used to treat young women who are excluded from such diseases as fibroma, ovarian tumors, endometriosis. There are three ways of hormonal hemostasis - estrogenic, gestagenic and mixed. Estrogenic is the injection of estrogens by intramuscular injection. The first two or three days they are performed every 2.5-3 hours. In the following days, the dose is reduced. After stopping bleeding, estrogens are replaced with gestagens and hormone therapy is administered. The gestagenic method is used if the patient does not have severe forms of anemia and decompensated cirrhosis of the liver. His goal - the creation of a level of hormones, which forcibly leads to the rejection of endothermia, covering the uterine cavity. Equivalent to this method, gonadotropic hemostasis using gonadotropin can be used.

Hemostasis during pregnancy

Pregnancy causes many changes in the body of women. One of them is an increase in the number of platelets and, as a consequence, the viscosity of the blood. This is a normal physiological process, caused by the preparation of the organism for the forthcoming birth. However, if too much platelet is formed, we can talk about thrombophilia, a condition that leads to blood clots in the blood vessels. Thrombophilia causes abortion, delayed fetal development, toxicosis and other complications. Therefore, it is absolutely necessary to do tests for hemostasis during pregnancy. What does this mean and when should it be done? Ideally, if such an analysis is conducted before conception, to prevent complications of bearing a baby. This analysis is performed on 14 items and gives an accurate picture of the blood condition. If a pathology is found, the doctor can prescribe a treatment. But this is optional. Sometimes it is sufficient to observe the dynamics of the development of the deviation.