Pulmonary Embolism (PE)

Pulmonary embolism  (PE) is the medical term used to reflect the lodging of a clot from another source into the arteries going to the lung.  These arteries usually transfer blood from the heart to the lungs. In the lungs the blood picks up Oxygen and through the heart is distributed to the rest of the body. If a clot is lodged in the pulmonary artery, it will interfere with oxygenation of blood. The condition can be fatal if the amount of clot is large enough to significantly interfere with the blood flow and Oxygen supply. The source of the clot can be the lower extremities or pelvis in most of the cases, but also it can be the upper extremities.

What are the Symptoms?

Symptoms depend on the volume of the clot and the location. They range from minor to severe symptoms and include:
Tachycardia: fast heart rate
Tachypnea: fast breathing
Shortness of breath
Chest pain, shoulder pain , jaw pain
Restlessness
Coughing
Spitting blood (hemoptysis)
Cardiac arrest
Death if the clot is large and interfering with the blood flow to both lungs.

Who is at risk for developing pulmonary embolism?

Patients who have the risks of deep vein thrombosis  (DVT) in general are at risk of developing pulmonary embolism. This include: family history of DVT, history of DVT, major surgery, pelvic surgery, prolonged bed rest, long rest such as in long trips, malignancy, pregnancy, patients taking hormonal therapy, smoking, obesity, dehydration, long bone fractures or hip fractures, orthopedic procedures such as hip and knee replacement.

How to prevent Pulmonary Embolism?

Patients who are at risk of developing PE should have some form of preventable measures during period that have the highest risk of developing PE such as at the time of surgery. Patients should tell their physicians if they had a history of DVT or PE even in the remote past. During prolonged rest, or surgery patients will be started to medicines to reduce the risk of PE. This can be in the form of injection or tablets. Other measures include using elastic stocking, mechanical devices around the leg to prevent pooling of blood which can lead to thrombosis. Frequent rest during long trips.

How to Diagnose PE?

Once suspected the diagnosis can be done using different imaging techniques such as:
Lung scanning using nuclear medicine materials.
Spiral CT scan with IV dye (CTA) to image the pulmonary arteries.
Pulmonary angiogram which is the last resort if other tests were not helpful.
In addition other tests will be helpful such as chest X-ray, EKG, D-dimer test which reflects the presence of clot in the body, Duplex US of the extremity veins

How to treat PE?

Once suspected, the patient is started on anticoagulation to reduce the risk of more clots to the lungs. After PE is confirmed patients will be kept on anticoagulation with injections and pills. The injections will be used for a limited period of time until the oral medicine is effective which can take few days in some cases. The oral medicine will be used for a variable period of time from few months to life long in some cases.

In other cases when the clot is major or when patients have other conditions, the physician may recommend more aggressive therapy to remove the clot. Such therapy include:

Thrombolysis:

Thrombolysis might be assisted with mechanical devices (Terellis)  (http://www.youtube.com/watch?v=aujNwoZKI_A) to help remove the clot or ultrasound waves (EKOS)  to help dissolve the clot.
Partial or complete removal of the clot might be done by minimally invasive techniques (angiojet thrombectomy), or surgery.  Surgery is used only in patients who are not responding to other measures or those who arrested  because of PE and still under resuscitation.

In patient who cannot be given anticoagulation or
at high risk of  complications from PE a filter is 
inserted in the main vein (IVC) to capture large
clots from reaching to the lungs.