Calhoun Liberty Hospital

Facts about Blood Clots & Pulmonary Embolisms

General Definitions

Thrombosis occurs when blood clots somewhere in the circulatory system. Depending on the size of the clot, there are multiple treatment options.

A pulmonary embolism is a blood clot in the lungs and can be treatable, depending on its size. The clot must be very small for effective treatment.

A pulmonary saddle embolism is a blood clot located at the bifurcation of the pulmonary arteries, high up in the chest.

How to Detect

Thrombosis and deep vein thrombosis clots can be detected through ultrasound and CT scans with contrast, although detection is often extremely difficult.

Small to medium pulmonary embolisms may be detected by CT scans, chest x-rays, decreased lung sounds and a higher concentration of d-dimer, a small protein fragment present in the blood. Again, detection can be extremely difficult.

A pulmonary saddle embolism is virtually undetectable because of its location.

What are some of the warning signs?

The warning signs for thrombosis can include shortness of breath, anxiety, chest pain, general soreness or weakness, coughing up pink foam, pain in the arms or legs and the loss of skin color below the clot.

The warning signs for a small pulmonary embolism that has not yet fully blocked any arteries may include shortness of breath, change in heart rate, change in blood pressure, tightness in the chest.

With a massive pulmonary embolism, including the majority of saddle embolisms, there are few if any warning signs. Often, a patient only has time to take a final breath.


Thrombosis and deep can be treated with blood thinning medication and stents to open up veins.

Microscopic pulmonary embolisms often shower the lungs and close off small air sacs within the lungs. These can be treated with blood thinning medication, supplemental oxygen and in some cases, respiratory support.

Small embolisms can be treated with blood thinning medication and can even self-resolve.

When large pulmonary embolisms occlude only one pulmonary artery, treatment is still possible because there is still at least one working pulmonary artery.

There is virtually no treatment for saddle embolisms that block both pulmonary arteries.


When a saddle embolism breaks loose, the clot can block both pulmonary arteries, depending on its size. Patients suffering from this condition — especially those with very large clots — will likely become unconscious within 15-30 seconds and are usually brain dead in less than four minutes.

Even with immediate CPR, there may not be any chance of survival because of the blockage at the bifurcation of the arteries. Treatment of a saddle embolism is almost always ineffective unless the embolism is microscopic.

A saddle embolism might possibly be treated with immediate endovascular surgery; however, Calhoun Liberty Hospital does not have this capacity. Without this immediate surgery, a saddle embolism that blocks both arteries is 99 percent lethal.