Pulmonary Embolism Causes

A comprehensive overview of pulmonary embolism covering subjects as: treatment, symptoms, diagnostics, research, causes, pictures and images
Pulmonary Embolism Causes

Pulmonary embolism causes

     Pulmonary embolism is caused by obstruction of pulmonary arteries. The main cause of this obstruction is represented by emboli which are formed in a deep vein of the lower limbs and which circulates to the lung, where it remains stuck at a lower pulmonary artery.

     Over 95% of the emboli which causes pulmonary embolism is formed proximal in the deep veins of the legs (the thigh). Emboli can also come from the deep veins of the legs - distal - (from the calf and foot), but also from the deep veins of the pelvis or upper limbs. However only 20% of emboli of the thigh increase in size, become detached and move towards the proximal areas.

     Emboli rarely form in the superficial veins, but these are rare pulmonary embolism causes.

     In exceptional cases pulmonary embolism can be caused by other substances than thrombi:

  • Tumors resulting from the rapid growth of cancer cells
  • Gaseous embolism (air bubbles in the blood resulting from trauma or surgical maneuvers)
  • Amniotic fluid resulting from a normal or complicated birth (exceptional)
  • Infectious substance
  • Fat, which can reach the bloodstream after fractures, surgery, trauma, severe burns or other conditions
  • Foreign substances such as catheter needles (which may break during surgery), mercury, iodine, cotton.

What causes pulmonary embolism?

     Emboli are established bodies, most often a blood clot, more rarely, from other components:

  • Detached fragment of a plaque buildup
  • A group of cancer cells
  • An air bubble
  • Fat, cholesterol crystals
  • Amniotic fluid during birth (rare)
  • Some organisms (microbes, parasites)

     Thrombus is composed of cells responsible for stopping the bleeding in case of cuts, wounds, called platelets or platelets and / or oxygen carrier cells, red blood cells. They are connected by a network of fibrin. It is formed, usually in the network of deep venous leg deep-vein thrombosis (DVT). Sometimes it can come off the formation place and is trained by the moving blood, meaning that it embolus towards the bloodstream of the lungs. Here it is impacting in a bowl, which shrank so much still no longer afford to move on. This situation is characteristic of pulmonary embolism.

     Pulmonary embolism etiology largely overlaps with that of venous thrombosis (VT), pulmonary embolism is, in most cases, complication of deep vein thrombosis (DVT). In almost 90% of cases of pulmonary embolism its source is located in a DVT, especially located in the lower limbs.

     In a proportion of cases, not exceeding 10-15%, the source of pulmonary embolism is found in the inferior vena cava thrombosis - often resulting from the extension of thrombosis in venous thrombosis in the basin and less frequently in cava thrombosis located in the upper limb higher veins or neck.

     The source of pulmonary embolism may be, at less than 10% of patients, the thrombi located right in the heart, especially in cases of chronic atria fibrillation, right ventricle heart attack, cardiomyopathy, intracardiac thrombosis often coexist with VT.

     Pulmonary thrombosis in situ is a rare cause of MET. It may complicate pulmonary hypertension (PAH) primitive, chronic obstructive bronchopneumonia, tumor infiltration of the arterial wall.

     Pulmonary venous thrombus dislocation and embolisation is often unpredictable: after a sudden muscle contraction, when all the sudden increase of venous pressure (sneezing, coughing, defecation), after a fracture reduction maneuvers to the affected leg or after massage performed intempensively.

     Since MET is preceded in most cases of the venous thrombosis, etiological factors responsible for the two pathological conditions are: venous stasis, venous wall injury and blood hypercoagulability.