pulmonary embolism causes

pulmonary embolism causes


 HOME> DISEASES> PULMONARY EMBOLISM: ALERT SIGNS PREVIOUSLY PREVENT THE ACCIDENT
Pulmonary embolism: warning signs often precede the accident

A pulmonary embolism is a sudden obstruction, partial or total, of one or more arteries of the lungs by a clot of blood. Frequently, it is a life-threatening risk if it is not managed quickly.


UNDERSTANDING DIAGNOSTIC TREATMENT PREVENTING MORE INFO
Pulmonary embolism: UNDERSTANDING
Words for the evils
Pulmonary embolism is caused by the migration of a blood clot, or "thrombus" that clogs an artery of the lung.

What is pulmonary embolism?
A pulmonary embolism corresponds to the migration of a clot ("thrombus"), which is formed in a vein (most often in the legs), via the general circulation, to an artery of the lung where it goes to block (as soon as the caliber of this one becomes smaller than the size of the clot): a small emboli will be distal, whereas a large clot will be able to stop a big artery.
In the initial stage called "phlebo-thrombosis", the clot is not very adherent to the wall of the vein and the risks of migration are high. Secondarily, the inflammatory reaction of the venous wall and the organization of the clot make the latter more adherent. At the 5th day, the adhesion is obtained and the risk of embolism is lower.
Clogging of a pulmonary artery with the clot will lead to an increase in "pulmonary arterial resistance", all the more important as the number of arteries, or the size of the arteries ("the vascular obstruction index") , is higher.
Constant when pulmonary arterial occlusion is greater than 30% of the vascular bed, resistance to blood flow is aggravated by arteriolar vasoconstriction and can reach very high values ​​that cause arterial hypertension in the pulmonary arteries (pulmonary arterial hypertension ) and dilatation with dysfunction of the right heart.
Embolism is all the more serious if it is large or occurs on an altered lung.

What are the signs of pulmonary embolism?
The wide variety of the inaugural manifestations of pulmonary embolism, as well as the lack of specificity of the signs, explain the difficulties of diagnosis and the fact that pulmonary embolism is often unknown.
The sudden obstruction of one or more branches of the pulmonary artery is accompanied at different degrees by symptoms of shortness of breath ("dyspnea") all the more severe as embolism is important, an acceleration of heart rate ("tachycardia"), pain in the chest wall (most often lateral, but sometimes behind the sternum and simulating myocardial infarction), irritative cough, sometimes with bloody sputum late. Unexplained anxiety may accompany shortness of breath.
The most serious forms of pulmonary embolism may be responsible for a loss of consciousness or "syncope" when standing up (always in connection with severe pulmonary embolism), a severe and inaugural fall in blood pressure. arterial (shock or "collapse"), and sometimes sudden death (exceptionally inaugural and, most of the time, related to recurrence of pulmonary embolism).
An embolism of the base of the lung can simulate a belly pain ("hypochondrium") and wrongly lead to an urgent disease affecting the abdomen ("abdominal surgical syndrome").What are the causes of pulmonary embolism?
All the circumstances favoring prolonged immobilization and bed rest accompanied by a "blood stasis", that is to say a slowing of the circulation in the veins of the legs, favor the formation of a clot (" phlebitis ") which can then migrate into the vein to the right heart and lung.
Venous thrombosis almost always affects the deep veins of the legs or small pelvis, more rarely the "inferior vena cava" (which drains the veins from the lower part of the body, and the renal veins.Exceptionally, thrombosis can arise directly in the right heart cavities, in the event of a disease such as an infectious endocarditis, a tumor or parasitic disease (alveolar echinococcosis) or during a diffuse thrombosome disease.
Any surgical procedure involving general anesthesia and a supine position, even of short duration, carries a risk of deep vein thrombosis, particularly small pelvis surgery, orthopedic surgery (especially hip operations), cast immobilizations, surgery. cancer.
Other diseases, which also promote blood stasis, are frequently associated with the formation of phlebitis ("deep vein thrombosis"), particularly heart failure which may itself be secondary to heart valve disease. ("Valvulopathy"), coronary artery disease ("coronary heart disease") or cardiac muscle disease ("cardiomyopathy").
All diseases that require prolonged bed rest may be involved: infectious diseases, blood cancers ("hematological diseases"), increase in the number of red blood cells ("polyglobulias"), cancers, in particular those of the stomach, pancreas and lungs.
Alterations in the vein wall may be responsible for pulmonary embolism (after trauma or phlebitis).
There are constitutional or acquired blood abnormalities (heparin thrombocytopenia) that may predispose to the occurrence of venous thrombosis. In the blood, the coagulation system consists of several proteins that activate in cascade = "cascade of coagulation"): this is the case in congenital deficits in antithrombin factor III, protein S, protein C or in the case of a deficiency of the physiological fibrinolytic system. These abnormalities of coagulation can be identified in 6-7% of venous thromboses.
The risk of embolism would also be doubled when you stay too long in front of any screen. The risk is greatest in people under 60 who watch an average of 5 hours of television a day and 6 times more than people of the same age who only spend 2 hours or less in front of a screen.
Contrary to popular belief, thrombosis and embolism are rare after childbirth or abortion.
On the other hand, contraception with certain pills (called 3rd and 4th generation), however low doses in hormones, clearly favors pulmonary embolism, especially when the taking of these pills is associated with other risk factors for thrombosis.
Very rarely, the embolus consists of material related to a cancer, greasy, amniotic, gaseous, septic or parasitic.

What are the complications of pulmonary embolism?
The severity of pulmonary embolism relies less on the importance of anatomical impairment than on the risk of early death that results.
This risk is now well stratified by scores that take into account the clinical signs of shock, hypotension, signs of right ventricular overload with dilation of this ventricle, which can be observed in echocardiography and on a CT scan, and an increase in its Doppler-doped blood pressure and blood markers (BNP or NT-pro-BNP assay), as well as the impairment of the heart muscle ("myocardium") which is best assessed by increase in the blood of a marker of myocardial pain: troponin.
Right ventricular dysfunction associated with myocardial involvement defines a high risk of death. On the other hand, the absenceRight ventricular dysfunction and myocardial involvement represent a low risk of death.