Thromboembolism of the pulmonary artery( PE) - Causes, symptoms and treatment. MF.
Pulmonary embolism( PE) is a serious disease characterized by complete or partial closure of the pulmonary artery lumen with a thrombus. As a rule, these are thrombi from the veins of the lower extremities or pelvis, less often from the right heart.
Pulmonary artery thrombosis.
Thromboembolism of the pulmonary artery is one of the main causes of sudden death. Unfortunately, only in 30% of cases it is diagnosed in vivo.
Causes of pulmonary embolism of the pulmonary artery
All risk factors for the development of pulmonary embolism can be divided into three large groups, depending on the leading mechanism of thrombus formation.
1. Damage to the vein wall. To this group include diseases such as thrombophlebitis( inflammation of the venous wall in combination with vein thrombosis), phlebitis( the formation of inflammation of the vein wall due to the attachment of an external infection, for example, with intravenous injections), as well as trauma accompanied by a complete or partial rupturevein walls( setting of an intravenous catheter, operations on vessels).
2. Local slowing of blood flow. The main importance is long-term bed rest, especially in combination with severe concomitant diseases, for example, heart failure, prolonged compression of tissues surrounding the vein, as in the process of gypsum fixation with significant fractures, as well as long stay in sitting position, including during flights, crossings.
3. Increased blood clotting. This risk factor prevails in individuals with certain hereditary diseases of the blood system, with chronic inflammation, with the use of contraceptives.
For thrombi formed in the lumen of the veins, the following characteristic is typical: one end of the thrombus is attached to the wall, the other freely moves in the lumen of the vein. With sudden movements, a part of the thrombus is separated, which, with blood flow, enters the right heart, and then into the pulmonary artery, causing, depending on the size of the thrombus, complete or partial closure of its lumen. The right ventricle of the heart is unable to push blood into the thrombosed pulmonary artery, it overflows and ceases to contract. Blood from the lungs does not enter the left heart, into the large vessels that drain from the heart, which causes a drop in blood pressure. In a very short period of time, the empty heart ceases to contract.
Symptoms of pulmonary embolism of the pulmonary artery
The pulmonary artery branched into increasingly narrow arteries, which is why it becomes the haven of a severed thrombus. The nature of external manifestations of pulmonary embolism depends directly on the volume of pulmonary vascular lesions.
• When "turning off" more than 50% of pulmonary vessels, including the main pulmonary arteries, develops massive pulmonary embolism. It is characterized by the development of shock( a drop in blood pressure, shortness of breath, loss of consciousness).This condition, as a rule, very quickly leads to a lethal outcome.
• Thrombosis of 30-50% of pulmonary vessels results in submissive pulmonary embolism of the pulmonary artery. At the same time against the background of shortness of breath of varying severity, blood pressure remains normal. Ill, pale, possibly cyanotic staining of the tips of the nose, ears, lips. He is agitated, restless, can not sit still. In some cases, a slight relief is achieved in a horizontal position. Perhaps the appearance of pain in the heart, rapid heartbeat.
• When less than 30% of the pulmonary arteries are affected, non-significant pulmonary embolism of the arises. At the same time, external manifestations may be absent at first. The fever, the appearance of a cough( possibly with an admixture of blood), pain in the chest makes it necessary to consult a doctor. When chest radiographs in the lungs, a characteristic triangular shadow is revealed - a lung infarction( a site of lung tissue death due to inadequate intake of nutrients and oxygen).
Lung infarction.
Examination for suspected thromboembolism of the pulmonary artery
As can be seen from the description, the external manifestations of thromboembolism of the pulmonary artery are nonspecific. Therefore, when identifying risk factors for the development of the disease and the appearance of the above complaints, it is first necessary to exclude PE as a serious condition that threatens life. Diagnosis of pulmonary embolism is carried out only in a hospital, so at the slightest suspicion, hospitalization is necessary.
In the diagnosis of PE, there are certain difficulties, since the complaints are nonspecific, and the tests do not have high sensitivity. The following types of diagnostics are common:
• Determination of D-dimers of blood. D-dimers are fibrin degradation products-an indicator of increased clot formation in the body. An increase in its value speaks in favor of thromboembolism of the pulmonary artery.
• Electrocardiography. In this case, signs of expansion of the right heart and increase of pressure in the pulmonary artery are revealed. Electrocardiography is informative for massive and submissive PE.
• Chest X-ray of the allows to diagnose an increase in the right heart, enlargement of pulmonary vessels, and also pulmonary infarction.
• Echocardiography provides information on the degree of cardiac dysfunction, and also allows you to determine the amount of pressure in the pulmonary artery.
• Ultrasound examination of the lower extremities veins reveals thrombi that could cause pulmonary embolism or are potentially dangerous for the development of PE.
• Spiral computed tomography .Intravenous contrast is introduced, then, using a computer tomograph, lung tissue is examined for thrombosis.
• Angiography is the most accurate method for determining pulmonary embolism, but at the same time, the most invasive. Intravenously, a contrast drug is dosed and a series of X-ray pictures is made. By "breaking" the coloration of a vessel make a conclusion about its closure with a thrombus.
Treatment of thromboembolism of the pulmonary artery
Treatment of PE is a complex process, the effectiveness of which is increased many times with the timely access for medical care. In this case, two main goals of treatment are singled out:
1. Salvation of life.
2. Warnings of recurrent thromboembolism of the pulmonary artery.
To save life, it is necessary to restore the permeability of the vessel as soon as possible. This goal is achieved by conservative and / or surgical methods. Intravenously administered drugs that dissolve the thrombus( streptokinase, alteplase, urokinase), as well as drugs that prevent further thrombosis( enoxaparin, dalteparin, heparin).
Thrombectomy - surgical removal of a thrombus, is indicated if it is not possible to medicate the effect.
Prevention of pulmonary embolism of the pulmonary artery
To exclude recurrence of pulmonary embolism, a thorough examination of the veins of the lower extremities and the pelvic region is necessary, identifying potentially dangerous areas and direct removal of thrombi, or the placement of filters( cava filter) into the lumen of the vessels holding the detached parts of the thrombus.
Doctor therapist Sirotkina EV