Many of us had to take hemostasis tests. What is it and why should it be checked? The answer to this question must begin with an explanation of what our circulatory system is and what mechanisms function in it.
The first function of hemostasis
Few people know that our blood is also tissue, only liquid. It consists of plasma, which is actually its liquid element, as well as red blood cells, white blood cells and platelets, which are in the plasma as if in suspension. All this continuously moves along the large and small arteries, veins and capillaries, delivering oxygen to the cells, nutrition and performing many other functions. This is a simplified model of our circulatory system. It is very important that the blood has the correct consistency. If it is too thick, blood clots form. If, on the contrary, it is too thin, a person suffers from excessive bleeding. It keeps our blood in optimal condition created by nature, a system called hemostasis. What is this system and what is the mechanism of its operation?
The second function of hemostasis
The hemostasis system is very complex. In addition to maintaining the necessary viscosity and fluidity in the blood, it provides wound healing (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 some reason the integrity of the vessel wall is violated, the blood rushes into the gap and the person begins to bleed. To stop it, the body starts the blood coagulation system , or hemostasis. It is 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 its work consists in causing a spasm of the damaged vessel, its narrowing and clogging of the “gap” with platelets. A crust forms on the damaged area, bleeding stops. People say "blood clotted." For those who have no 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, adhesion begins, that is, subsidence, adhesion of platelets. Their shape becomes more rounded, and spikes and processes appear on the surface, providing a strong bond with other platelets. As a result, they are glued together (aggregation), and a plug of platelets is formed. In 1 μl of blood should be from 150 to 300 thousand healthy platelets of the correct form. Otherwise, the coagulation process is violated.
What is secondary hemostasis
Bonded platelets begin to release active biological and chemical substances into the bloodstream, causing narrowing of the vessel walls and the formation of secondary, irreversible bonding. Along with platelet factors, the thrombin enzyme, the most important for blood coagulation, is released, which in turn affects the formation of fibrin protein. The fibers of this protein are the basis of a blood clot. They create, as it were, a network in which red blood cells and white blood cells become entangled. Fibrin is obtained from another protein - fibrinogen. To determine its amount in the blood, they donate blood for hemostasis. What is fibrinogen and what is its importance? This protein plays a leading role in blood coagulation. Its excess causes thrombosis, and the lack of hemorrhage. The norm is considered to be 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, flu, and several other conditions, including severe burns, surgery, and some medications. The amount of protein less than 1.5 g / l causes cirrhosis, DIC, hepatitis, myelogenous leukemia, toxicosis, cesarean section during childbirth, polycythemia, snake bites, deficiency of vitamins B12 and C.
The third function of hemostasis
The final stage of wound healing is fibrinolysis, for which hemostasis is also responsible. What it is? Fibrinolysis involves the elimination of a clot and the restoration of blood circulation in a damaged blood vessel. From the first seconds of the wound healing process and the beginning of blood coagulation in the plasma, the plasminogen enzyme is activated. It produces a plasmin protein that breaks down fibrin, and with it a blood clot. Between the formation of a blood clot and its dissolution, there must be a balance, which ensures hemostasis. As you can see, this system is very complex. Failure, even at its smallest link, leads to disruption of the entire chain and serious diseases.
Violation of hemostasis. What is it and how to identify it
The following violations are distinguished:
- increased blood coagulability (hypercoagulation), which leads to spontaneous formation of blood clots in arteries, veins and internal organs. This is fraught with serious 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.
- reduced blood coagulation (hypocoagulation), leading to spontaneous bleeding. It is observed with hemophilia, von Willebrand disease, platelet deficiency in the blood or their pathological changes, liver diseases, insufficiency of coagulation factors, thrombocytopathy.
- DIC syndrome, in which both types of coagulation are present.
To find out the cause of abnormalities in blood coagulation, a hemostasiogram (coagulogram), or an analysis of hemostasis, is performed. What it is? This analysis is carried out for pregnant women, patients before surgery, people suffering from diseases of the heart and blood vessels, as well as patients with pathologies of blood coagulation. The coagulogram is the base, in which hematocrit, hemoglobin, the number of all blood factors and a number of other indicators are determined. The second type of coagulogram is an expanded one, assigned mainly to people with blood pathologies and pregnant women.
Hormonal hemostasis as a treatment method
In some women, menstrual irregularities are observed , expressed in heavy, prolonged bleeding. To eliminate the problem, hormonal hemostasis is used. What it is? The method is used to treat young women who exclude diseases such as fibroma, ovarian tumors, endometriosis. There are three ways of hormonal hemostasis - estrogenic, gestagenic and mixed. Estrogen is an injection of estrogen intramuscularly. The first two to three days they are performed every 2.5-3 hours. In the following days, the dose is reduced. After stopping the bleeding, estrogens are replaced by progestogens and hormone therapy is carried out . The gestagen method is used if the patient does not have severe forms of anemia and decompensated liver cirrhosis. Its goal is the creation of such a level of hormones in which endothermia, which covers the uterine cavity, is forcibly rejected. Gonadotropic hemostasis using gonadotropin is equivalent to this method.
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 result, the viscosity of the blood. This is a normal physiological process caused by the preparation of the body for the upcoming birth. However, if too many platelets form, we can talk about thrombophilia, a condition that leads to the formation of blood clots in the blood vessels. Thrombophilia causes termination of pregnancy, fetal growth retardation, 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 carried out before conception, to prevent complications of bearing a baby. This analysis is performed on 14 points and gives an accurate picture of the state of the blood. If a pathology is detected, the doctor may prescribe treatment. But this is optional. Sometimes observing the dynamics of the deviation is enough.