Introduction

PULMONARY EMBOLISM  is a blood clot in the lungs. It reaches the lungs after breaking of a vessel, travelling from the vessel to the lung and gets lodged in the lung artery. The clot is usually located in a leg or arm artery. In the lungs, it causes restriction of blood flow, decreased oxygen levels in the blood within the lungs and raised blood pressure within the pulmonary arteries.

The term “embolism” is derived from the greek “embolos” which refers to stopper or plug.

 

 Key Facts & Statistics

Key facts and statistics that surround pulmonary embolism

• Every year, pulmonary embolism affects nearly 0.9 million persons in the United States. Of these, 60,000 to 100,000 people succumb every year.
• In 2014, an article in the Journal Circulation stated that the chance of a clot breaking off from the vessel wall and leading to development of PE is more common during the initial few days through 4 weeks from the formation of clot.
• Almost one-third of individuals with PE die before receiving a diagnosis and treatment.
• The risk of succumbing to PE is greater when one has a heart or lung condition.

 

Risk Factors

What are the risk factors for pulmonary embolism?

Risk factors for the development of PE include:

• Certain health conditions such as:

1.  Deep vein thrombosis (DVT).
2.  Blood clotting disorder.
3.  Diabetes.
4.  Cancer.

•  Age. Being 60 years and above.
• Overweight or obesity.
• Being pregnant or having delivered within the previous 6 weeks.
• Central venous catheterization through the arm or leg.
• Family history of PE.
• Immobility for long periods of time.
• Hormone-based birth control
• Surgery.

 

 Causes

What are the causes of pulmonary embolism?

• The most common cause of PE is formation of a thrombus within a major vein that breaks off soon and travels through the right heart side becoming lodged in the pulmonary circulation. This becomes a pulmonary embolus.
• Typically, a pulmonary embolus happens when a deep vein thrombus in the limbs (arms or legs) travels through the vein into the heart and finally to the arteries within the lungs.
• Less common causes of PE are:

1.  Fat embolus. Entry of fat cells into circulation, they can lodge in the pulmonary circulation. Fat embolism is commonly caused by fracture of long bones or the pelvis. The marrow of these bones has a massive quantity of fat.
2.  Air embolism. Entrance of air into the circulatory system can cause air embolism. More than 100 ml of gas is needed for thus to occur.
3.  Amniotic fluid embolism. This is a rare, life-threatening condition where the amniotic fluid enters the circulatory system during a childbirth, leading to an acute pulmonary embolism.
4.  Tumor embolism. It occurs a s a complication of end-stage cancer where the cancerous cells enter the circulation leading to occlusion of pulmonary vessels.

 

 Signs & Symptoms

What are the signs and symptoms of pulmonary embolism?

 

• Signs and symptoms of pulmonary embolism include:

1. Tachynea (rapid respiratory rate).
2. Wheezing.
3. Sudden shortness of breath,
4. Cyanotic skin (pale and bluish).
5. Tachycardia.
6. Excessive perspiration.
7. Anxiety.
8. Faintness.
9. Coughing up blood.

 

 Diagnostic Procedures  & Tests

How is pulmonary embolism diagnosed?

 

• Review of presenting signs and symptoms, along with risk factors.
• Tests:

1. Blood tests such as D-dimer test.
2. Echocardiogram.
3. Cimputed tomography (CT) angiogram.
4. Leg ultrasound.
5. Pulse oximeter. It is attached on the fingertip to check for blood oxygen levels.
6. Pulmonary angiogram.
7. Chest X-ray.

 

 Treatment and Management

How is pulmonary embolism treated?

 

Anticoagulants.

• Main strategy of treatment is administration of anticoagulant agents.
• They decrease the ability or tendency of blood to clot.
• The clinician orders for regular blood tests such as prothrombin time test to check how rapid the blood clots. This can help in determination of the right doses.

 

Compression stockings.

They are used to improve blood flow within the legs. They are oftenly used by patients with DVT.

 

Thrombolytic therapy.

These medications dissolve the clot. They are administered in the emergency department or intensive care unit.

 

Medical procedures.

Being a life-threatening condition, surgery or catheterization to remove blood clot can be done in cases where medications have failed to be effective.

 

 Complications

What are the complications of pulmonary embolism?

• Pulmonary embolism can lead to development of:

1. Cyanosis.
2. Pulmonary hypertension.
3. Heart attack.
4. Shock.
5. Stroke.
6. Death of lung tissue (pulmonary infarction).

Prevention

How do we prevent pulmonary embolism?

• Several strategies can be employed to lower the risk of developing blood clots or pulmonary embolism. These are:

1.  Avoiding smoking.
2. Avoid crossing the legs.
3. Take in plenty of fluids. However, limit alcohol and caffeine intake.
4. Avoiding sitting for long periods.
5. Keep a healthy weight.
6. Put on compression stockings when travelling for long journeys such as in a plane.
7. Avoid wearing tight-fitting clothing.