Pulmonary Embolism

A pulmonary embolism is a blood clot that forms in a vein, travels through the bloodstream, and lodges in the lungs. A pulmonary embolism is a medical emergency because a large embolism, or sometimes many repeated smaller ones, can be fatal in a short time.



The symptoms can depend on the location and size of the blood clot. Shortness of breath is the most common symptom. Other symptoms include rapid breathing; anxiety and restlessness; chest pain, which might extend into the shoulder, arm, neck, and jaw; coughing or spitting up blood; feeling lightheaded or fainting; and having a rapid heartbeat.

Risk Factors

The type of clot that is likely to cause a pulmonary embolism usually originates in the veins deep in the muscles. This condition is called deep vein thrombosis (DVT). DVT usually occurs in the leg or pelvic veins; although less commonly it can also sometimes occur in the arm veins.

Factors that increase the risk of DVT or pulmonary embolism include:

  • Having a close family member who has had a pulmonary embolism
  • Inherited blood clotting abnormalities
  • Major surgery
  • Hip or leg fractures
  • Standing or sitting still for long periods of time, such as on a long plane trip or car ride
  • Cancer
  • Obesity
  • Smoking
  • Having a history of a heart attack or stroke
  • Pregnancy, taking birth control pills, or taking estrogen replacement therapy


  • History and Physical Examination
  • Chest X-Ray
  • Cctrocardiography (ECG) which measures your heart's electrical activity
  • D-dimer enzyme-linked immunosorbent assay, a blood test that shows an increase of a type of protein that may rise after a pulmonary embolism
  • Lung scanning, which measures blood flow in your lungs and your air intake
  • Spiral computed tomography (CT) scan
  • Pulmonary angiography, which shows x ray pictures of the blood vessels in your lungs
  • Duplex ultrasound, which allows your physician to measure the speed of blood flow and to see the structure of your leg veins
  • Venography, which shows x-ray pictures of your leg veins



If you have a pulmonary embolism, your physician or vascular surgeon may administer an anticoagulant drug called heparin intravenously as initial treatment. Anticoagulants help prevent your blood from clotting too easily. Heparin helps prevent clots from forming and keeps clots you already have from growing. Eventually, your body breaks up the clot that has caused your pulmonary embolism. After initial therapy with Heparin, daily oral anticoagulation medications are started.


If you have a large pulmonary embolism, or you have another medical condition, the vascular surgeon may recommend more aggressive treatments. A treatment called thrombolysis can dissolve the clot. In this procedure, the vascular surgeon injects clot-dissolving drugs through a catheter directly into the clot. Thrombolysis has a higher risk for bleeding complications and stroke than anticoagulant therapy but may be effective more quickly, a feature that may be important if the pulmonary embolism is large.

Suction Thrombectomy

In you are unable to receive anticoagulant therapy or thrombolysis, the vascular surgeon may attempt to remove the clot using a catheter technique. Using this technique, called suction thrombectomy, the vascular surgeon guides a catheter through your blood vessels to your pulmonary embolism. The catheter shoots a salt solution into the blocked artery. The water pressure pulls the clot toward the tip of the catheter and breaks up the clot.

Open Surgery

Rarely, physicians recommend surgery for a pulmonary embolism. The procedure is called pulmonary embolectomy. You may need this surgery if you have life-threatening blockages in your lungs that are not responsive to other treatments.

Vena Caval Filter

In some circumstances, your physician may recommend placement of a special metal filter in your main vein, the vena cava, if drug therapy isn't feasible or isn't enough to prevent pulmonary embolisms from recurring. This device is called a vena cava filter. The vena cava is a large vein in your abdomen that carries blood back to your heart and lungs. Vena cava filters can trap the clots that break away from your leg veins before they can reach your lungs. The vascular surgeon inserts the filter into your vena cava through a catheter. Some of these filters are left in place permanently and some can be removed.

Risks of Operation

Anticoagulation, both IV and oral forms have a risk of bleeding. Thrombolytic therapy has a higher incidence of bleeding than anticoagulation. The patients have to be monitored very closely in the ICU when these drugs are used. Open thrombectomy and suction thrombectomy are very high risk procedure and are performed rarely and as a last resort.