Pulmonary Thromboembolism - Causes, Symptoms, Diagnosis, and Treatment

What Is Pulmonary Thromboembolism?

Pulmonary thromboembolism is a pulmonary artery blockage by blood clots reaching the lungs from veins in the lower extremities or other body parts. The clots lead to blocking the blood supply to the lungs. Pulmonary embolism is a life-threatening situation. Immediate treatment reduces the risk of death. Precautions to prevent blood clots can protect against pulmonary thromboembolism.

What Are the Symptoms of Pulmonary Thromboembolism?

Pulmonary embolism symptoms depend on lung involvement, clots' size, and the underlying disease's presence. Common signs and symptoms of pulmonary thromboembolism include the following:

• Shortness of breath.

• Chest pain.

• Cough.

• Rapid heartbeat

• Lightheadedness.

• Increased sweating.

• Fever.

• Leg pain and swelling.

• Clammy skin due to cyanosis.

What Are the Causes of Pulmonary Thromboembolism?

A pulmonary embolism occurs when a blood clot wedges into an artery in the lungs. These blood clots are from the veins of the legs. This condition is called deep vein thrombosis.

Many clots are involved in pulmonary embolism. As a result, the lungs cannot provide oxygen to the rest of the body. The causes include the following:

• Other foreign materials cause blockages in the blood vessels.

• Fat from the marrow.

• Part of a tumor.

• Air bubble.

• Smoking.

• Overweight.

• Supplemental estrogen.

• Pregnancy.

The following are the risk factors for pulmonary thromboembolism:

• Blood clot in a vein of the lower extremity.

• Medical conditions and ongoing treatments.

• Personal or family history of pulmonary embolism in the past.

• Heart disease.

• Cancer.

• Surgery.

• Long-term immobility.

What Are the Complications of Pulmonary Thromboembolism?

Pulmonary embolism is a life-threatening condition. Pulmonary embolism can cause pulmonary hypertension, and the blood pressure in the lungs and the right side of the heart is elevated. In addition to obstructions in the arteries in the lungs, the heart works harder to push blood through such vessels and increases blood pressure.

Emboli result in chronic pulmonary hypertension, also called chronic thromboembolic pulmonary hypertension.

How to Prevent Pulmonary Thromboembolism?

Preventing clots in the deep veins in the legs can prevent pulmonary embolism.

• Blood thinners are the medications given to people at risk of clots before and after surgery, with a medical history of heart attack, stroke, or cancer.

• Compression stockings squeeze the legs and help veins and leg muscles move blood efficiently. They prevent blood from stagnating during and after surgery.

• Elevating the legs when possible and during the night can be beneficial.

• Moving as soon as possible after surgery.

• Pneumatic compression uses thigh-high or calf-high cuffs that inflate with air and deflate to massage, squeeze the veins, and improve blood flow.

Following are the measures to follow.

• Drink plenty of fluids.

• Take a break from sitting.

• Do a few deep knee bend stretches.

• Fidget in the seat.

• Wear support stockings.

How to Diagnose Pulmonary Thromboembolism?

Pulmonary embolism is difficult to diagnose in people with underlying heart or lung disease. However, the following tests can be done to diagnose pulmonary thromboembolism.

• Blood Tests: A blood test detects the clot-dissolving substance D dimer. High levels signal an increased chance of blood clots. Blood tests also measure oxygen and carbon dioxide in the blood. A clot in a blood vessel lowers the oxygen level. Blood tests can rule out an inherited clotting disorder.

• Chest X-Ray: Chest X-rays are noninvasive tests showing images of the heart and lungs. X-rays cannot diagnose pulmonary embolism and can appear normal even with the presence of pulmonary embolism.

• Ultrasound: A noninvasive test, ultrasonography or duplex scan, or compression ultrasonography uses sound waves to scan the veins in the thigh, knee, calf, and arms to look for deep vein blood clots. A transducer device is rolled over the skin to direct the sound waves toward the veins tested. These waves are reflected in the transducer. This creates a moving image on the screen.

• Computed Tomography Pulmonary Angiography: CT scanning generates X-rays and produces cross-sectional images of the concerned area. For example, CT pulmonary embolism study creates 3D images to detect abnormalities like a pulmonary embolism in the lungs' arteries. In addition, the contrast material can be injected intravenously to scan pulmonary arteries.

• Ventilation-Perfusion Scan (V/Q scan): To avoid radiation exposure, a V/Q scan can be performed. First, a tracer is injected into a vein. The tracer maps blood flow and compares it with the airflow to the lungs to determine if the blood clots are causing the symptoms of pulmonary hypertension.

• Pulmonary Angiogram: An angiogram shows a picture of the blood flow in the lungs' arteries. It is an accurate way to diagnose pulmonary embolism. In a pulmonary angiogram, a flexible tube is inserted into a large vein and threaded through the heart into the pulmonary arteries. A special dye is injected into the catheter, and a series of X-rays will be obtained.

• Magnetic Resonance Imaging: MRI is an imaging technique that uses a magnetic field and radio waves to create images of organs and tissues.

What Is the Treatment of Pulmonary Thromboembolism?

Treatment of pulmonary embolism necessities the prevention of blood clots from turning bigger and preventing new clots from the formation. Immediate treatment is needed to avoid serious complications or death.

Medications: Blood thinners or anticoagulants are the drugs that prevent the clots already present from enlarging and new clot formation. Heparin is a commonly used anticoagulant injected through veins or under the skin. It acts fast and is combined with an oral anticoagulant, like Warfarin. Bleeding is the most common side effect of anticoagulants. Clot dissolvers or thrombolytics can dissolve clots quickly when given through the vein.

Surgical Procedures: Clot removal surgery can be performed in cases of life-threatening clots in the lung. A vein filter is a catheter placed in the inferior vena cava that leads from the legs to the right side of the heart. This filter prevents the movement of clots to the lungs.

Conclusion

Pulmonary thromboembolism occurs due to a clot in the pulmonary artery. The goals of treatment include clot resolution and decreasing the risk of recurrence. Additional goals are to reduce the risk of complications like death and pulmonary hypertension. Treatment choice depends on symptoms and patients, bleeding complications, and comorbidities. Treatment choice available includes nonpharmacologic and pharmacologic therapy with thrombolytics and anticoagulants.