A pulmonary embolism (PE) occurs when a blood clot becomes trapped in the smaller network of vessels of the lungs. A PE is almost always accompanied by the experience of Deep Vein Thrombosis (DVT), a blood clot in the extremities that is typically experienced in the legs that may or may not be diagnosed
A PE is life-threatening as the impacted lung tissue is robbed of oxygen and dies, which also prevents the rest of the body from receiving oxygen.
Anatomy of a Blood Clot
Arteries and veins are responsible for circulating blood throughout the body. Veins are low-pressure vessels and carry deoxygenated blood from the body back to the heart. Arteries, conversely, are muscular and high-pressure vessels that transport oxygen-rich blood from the heart to the rest of the body.
On a day-to-day basis, blood clots form as a result of impact or injury and dissolve in the blood stream without medical intervention. Blood clots that donâ€™t dissolve, however, can be dangerous and even life threatening. The reason for this is when a clot does not dissolve, the heart continues to push blood through narrowed/ obstructed passages. Clotting in a vein can obstruct the flow of blood from the body to the heart, which causes swelling, tenderness and pain. In DVT, a blood clot in the leg could be released into the blood stream and travel through the heart and into the lungs, which causes a pulmonary embolism
Symptoms of Pulmonary Embolism
The signs of a pulmonary embolism, a clot that has traveled to the lung include:
- Sudden shortness of breath
- Sudden sharp pain over the affected region of the lung
- Chest pain that worsens with a cough
- Dizziness, light-headedness, and fainting
- Expelling blood when coughing
These symptoms often occur after experiencing a DVT. A DVT usually affects the lower leg and thigh and almost always presents on one side of the body.
DVT symptoms include:
- Sudden or gradual pain
- Tenderness and swelling of the leg especially in the area of the calf muscle
Diagnosing Pulmonary Embolism
A doctor will form their diagnosis based on assessing your Pulmonary Embolism symptoms along with a physical exam and discussion of a potential previous DVT. A doctor will most likely also consider a patientâ€™s general health, other prescription medicines and whether or not theyâ€™ve had surgical procedures, injuries or treatment for cancer. A physician may employ these tests to diagnose this condition:
- Blood Tests â€“ A blood test will help measure D-dimer levels, which are heightened in an effort to dissolve blood clots in the body. A physician may order other tests in order to rule out other causes of the symptoms.
- CT scans / MRI – these scans produce a visual topography of an individuals veins, which can aid in locating a clot. Clots are readily seen in the chest in these forms of imaging. A physician may order an x-ray to rule out other causes of the symptoms.
Treatment for PE
When a patient is diagnosed with a pulmonary embolism, the aim of their treatment is to break down the current clot. Once blood clots are managed, treatment is geared towards preventing another occurrence of deep vein thrombosis.
Common Treatments include:
Blood thinners (anti-coagulants) these medications decrease the bloodâ€™s ability to clot, prevent existing clots from growing as well as reduce the risk of additional clots developing. These medications are taken for a period of 3- 6 months or for life if the clot was not provoked by trauma or immobility. These medications include daily injections or oral medications. Traditional oral therapy is completed using the drug warfarin, which is accompanied with weekly blood resting to adjust doses. However, new agents such as rivaroxaban (Xarelto) have been approved for use and to treat and prevent blood clots and do not require regular monitoring.
These medications increase a patientâ€™s risk of bleeding. If bleeding does occur without resolution then the patient should seek emergency medical attention.
Risk Factors for Pulmonary Embolism
Studies show that some people are genetically pre-disposed to abnormal clotting complications but anyone can develop a blood clot from trauma, immobility or a pre-existing medical condition that affects the bloodâ€™s ability to clot.
The risk of the blood clot in the leg leading to a pulmonary embolism is heightened when certain risk factors are present.
Risk factors also include:
- Age greater than 60 years old
- Heart Disaese and High Blood Pressure
- Pancreatic, Ovarian, Lung Cancers and Chemotherapy
- Regular immobility (wheelchair, travel)
- Excess weight or obesity women who smoke, have high blood pressure and are also overweight are extremely vulnerable to abnormal clotting issues
- Estrogen Therapy women taking oral contraceptives and anyone introducing supplemental estrogen into the body (hormone therapy) increase the risk of clotting
- Injury from sports or physical activity due to overuse or trauma
- Family History (genetic pre-dispositions and mutations)
Complications Associated with DVT
As discussed, the most serious complication associated with blood clots is a pulmonary embolism. Nearly 25% of those who experience a PE will die. The chances of survival, however, are high if the condition is identified and treated promptly. It is, therefore, essential to notify a doctor immediately if you experience any symptoms. The reason for this high risk is the lack of oxygen being transferred to vital tissues of the body because of a reduction in gas exchange from carbon dioxide to oxygen in the lungs. With sufficient oxygen tissues in the brain and body begin to die.
Patients often make a full recovery after a pulmonary embolism if treated promptly. The possibility for recurrence of PE is very high and patients should be on blood thinning / anticoagulation therapy long term to reduce this risk.