Pulmonary embolism

πνευμονική εμβολήWhat is pulmonary embolism?

Pulmonary embolism is the obstruction of blood vessels that carry blood to the lungs. Usually the blockage is caused by a clot formed elsewhere in the body and carried to the lungs via the bloodstream. In rare cases pulmonary embolism can be due to air bubbles, fat or tumor cells.

Why are blood clots in the pulmonary circulation a dangerous situation?

If a clot is formed and moved to the lungs, it may block a blood vessel in the lungs. Thus, blood can no longer be transferred to lung areas where there is oxygen enrichment. This can result in necrosis of a lung segment, difficulty to breathe and ultimately hypoxia that can lead to death. Most blood clots initially form in legs and pelvis and afterwards they move to the lungs with the bloodstream.

What are the symptoms of pulmonary embolism?

These may include:

  • Shortness of breath and difficulty breathing
  • Chest pain, especially during a deep breath
  • Cough with or without hemoptysis
  • Tachycardia

If you experience any of the above, you should call an ambulance immediately. Your doctor will then do some tests to determine whether there is indeed a clot in the arteries of the lungs. This is a very serious condition that can lead the patient to death if not diagnosed and treated promptly.

What are the symptoms of thrombosis in the legs?

These may vary depending on whether the thrombosis affects deep or superficial veins of the legs.

Clots in deep veins are the most dangerous to health. They can cause the following:

  • Swelling of the legs
  • Local pain
  • Redness and local warming

Clots in superficial veins can cause pain, redness and inflammation. They can also cause stiffness of veins and make them look like strings. This usually occurs in the veins below the knee.

If you think that you suffer from thrombosis in the legs, call your doctor immediately. Usually superficial thromboses are not dangerous. In contrast, clots in the deep venous system are dangerous because they can be transported centrally, with bloodstream, to the lungs. Your doctor will recommend you some tests in order to understand whether clots are located in deep or superficial venous network.

Is there a test for the diagnosis of pulmonary embolism?

Yes, there are several tests that your doctor may advise you, in order to check pulmonary embolism. The most common of these are:

  • D-dimer. This is a substance in blood that increases when thrombosis exists in any blood vessel.
  • Pulmonary angiography using CT (CT-PA). By using X-rays and computer software, CT shows human vessels after a radiologist injects a contrast agent in a patient’s peripheral vein.
  • Ventilation-perfusion scan (V / Q scan). The patient inhales a small amount of radioactive substance, as another radioactive substance is injected in his blood. Then, by using a machine (γ-camera), nuclear medicine doctor gets images of patient’s lungs and can determine whether an artery in the lungs is obstructed.
  • Classic pulmonary angiography. In this test, a tiny tube is placed into a large vein usually in the leg. Subsequently, the tube is  promoted upward to the lungs and then the examiner injects a contrast substance into the tube so that finally a radiological imaging of pulmonary circulation is obtained.

What is the treatment of pulmonary embolism?

Pulmonary embolism can be treated with drugs that dissolve clots or the prevent them to grow further. Some drugs are administered directly into the veins, some into the skin and some by the mouth. If there is a reason you can not take the above medications, or the medications are not enough to treat pulmonary embolism, your doctor may recommend you another treatment option. So, in specialized centers, it may be the surgical removal of thrombi from lung vessels or a removal using a small catheter. People who have thrombosis usually take an oral drug called “warfarin” for at least 3 months (usually more than 3 months). This drug prevents further growing of the already formed clots and also prevents the formation of new clots. This is very important because often, people who experience their first episode of thrombosis, suffer from thrombosis in the future, in the same or another part of their body. So basically, warfarin helps in preventing recurrence of thrombosis. If your doctor has prescribed warfarin, it is necessary to take your medicine exactly as is prescribed by your doctor. If you forget or miss a dose, immediately contact your doctor. You will need some blood tests during treatment with warfarin. This is necessary because the effect of warfarin may change over time and it may also get influenced by diet. If the action of the drug has changed, your doctor will adjust its dosage. This avoids experiencing high blood levels of the drug that can lead to bleeding, or low blood concentration that is insufficient in preventing clotting formation.

Another treatment option that is appropriate under certain conditions, is to place a filter into the inferior vena cava. The vena cava is the large vein that carries blood from the legs and lower halves of the body to the heart. The filter is placed within this vein. So it can trap any clots that would otherwise be transferred from the legs to the heart and eventually to the lungs. Your doctor may suggest you the inferior vena cava filter in the following situations:

  • It is not safe to take warfarin or you can not take it anyway.
  • Clots are formed even though you are taking warfarin
  • You experience severe bleeding while on warfarin

Is there anything that you can make to help the situation?

Yes. Many times people suffer thrombosis because they are sitted for several hours. For example, during long air flights, passengers have an increased risk of thrombosis. So, thrombosis can be prevented if someone does the following:

  • He gets up and walks every one to two hours.
  • Avoids smoking before and during flight
  • Is dressed in loose, comfortable clothing
  • Moves his feet while sitting at frequent intervals
  • Drinks enough fluids
  • Wears special elastic stockings
  • Avoids consumption of drugs that cause drowsiness during the trip, because in this way he will remain motionless in the seat for several hours.

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