Chirurgia

General surgery

Pulmonary embolism

Pulmonary embolism is a blockage in one of the pulmonary arteries in the lungs. In most cases it occurs when a blood clot, most commonly formed in the deep veins of the legs (deep vein thrombosis, or DVT), gets lodged in an artery in the lungs.

This blockage can lead to infarction, where the portions of the lung served by the blocked artery are deprived of blood and may die. This makes it harder for the lungs to deliver oxygen to the rest of the body.

Because the clots block blood flow to the lungs, pulmonary embolism can be life-threatening. However, prompt treatment greatly reduces the risk of death. Taking measures to prevent blood clots in your legs will help protect you against pulmonary embolism.

In many cases, multiple clots are involved in pulmonary embolism. These clots can cause pulmonary embolism, which can be caused by substances other than blood clots, such as fat from the marrow of a broken long bone, part of a tumor, or air bubbles.

About one-third of people with undiagnosed and untreated pulmonary embolism don’t survive, but prompt diagnosis and treatment significantly reduce this risk.

Pulmonary embolism can also lead to a condition characterized by pulmonary hypertension, high blood pressure in the lungs and right side of the heart. When blood vessels in the lungs become obstructed, the heart must work harder to pump blood through them, increasing blood pressure and eventually weakening the heart.

In rare cases, small emboli can occur frequently and develop over time, resulting in chronic pulmonary hypertension, also known as chronic thromboembolic pulmonary hypertension.

Symptoms

Symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots, and whether you have underlying lung or heart disease.

Common signs and symptoms include:

• Shortness of breath: It typically appears suddenly and always gets worse with exertion.
• Chest pain: It may feel like you're having a heart attack. The pain is often sharp and felt when you breathe in deeply, often stopping you from being able to take a deep breath. It can also be felt when you cough, bend or stoop.
• Cough: It may produce bloody or blood-streaked sputum.

Other signs and symptoms that can occur with pulmonary embolism include: rapid or irregular heartbeat, lightheadedness or dizziness, excessive sweating, fever, leg pain or swelling, and clammy or discolored skin (cyanosis).

Risk factors

You’re at higher risk if you or any of your family members have had venous blood clots or pulmonary embolism in the past. Additionally, certain medical conditions and treatments can increase your risk, such as:

• Heart disease: Cardiovascular disease, particularly heart failure, makes clot formation more likely.
• Cancer: Certain cancers, especially brain, ovary, pancreas, colon, stomach, lung, and kidney cancers, and cancers that have spread, can increase the risk of blood clots. Chemotherapy further increases this risk. Women with a personal or family history of breast cancer who are taking tamoxifen or raloxifene are also at higher risk of blood clots.
• Surgery: Surgery is one of the leading causes of problem blood clots. For this reason, medication to prevent clots may be given before and after major surgery, such as joint replacement.
• Disorders that affect clotting: Some inherited disorders affect blood, making it more prone to clotting. Other medical disorders, such as kidney disease, can also increase your risk of blood clots.
• Prolonged immobility: Blood clots are more likely to form during periods of inactivity, such as:
  • Bed rest: Being confined to bed for an extended period after surgery, a heart attack, leg fracture, trauma, or any serious illness makes you more vulnerable to blood clots. When the lower extremities are horizontal for long periods, the flow of venous blood slows, and blood can pool in the legs, sometimes resulting in blood clots.
  • Long trips: Sitting in a cramped position during lengthy plane or car trips slows blood flow in the legs, which contributes to the formation of clots.
• Other risk factors:
  • Smoking: For reasons that aren’t well understood, tobacco use predisposes some people to blood clot formation, especially when combined with other risk factors.
  • Being overweight: Excess weight increases the risk of blood clots, particularly in people with other risk factors.
  • Supplemental estrogen: The estrogen in birth control pills and in hormone replacement therapy can increase clotting factors in your blood, especially if you smoke or are overweight.
  • Pregnancy: The weight of the baby pressing on veins in the pelvis can slow blood return from the legs. Clots are more likely to form when blood slows or pools.

Prevention

Preventing deep vein thrombosis (DVT) is crucial in preventing pulmonary embolism. Most hospitals take proactive measures to prevent blood clots, including administering blood thinners (anticoagulants) to individuals at risk of clots before and after surgery, as well as to those admitted to the hospital with medical conditions such as heart attack, stroke, or complications of cancer.

Compression stockings, which steadily squeeze the legs, help veins and leg muscles move blood more efficiently. They offer a safe, simple, and inexpensive way to prevent blood from stagnating during and after general surgery.

Leg elevation, either when possible or during the night, can also be very effective in reducing the risk of pulmonary embolism. Raising the bottom of the bed 4 to 6 inches (10 to 15 cm) with blocks or books can help improve blood flow.

Physical activity is essential for preventing pulmonary embolism and hastening recovery after surgery. Encouraging patients to move as soon as possible after surgery, even on their day of surgery, is crucial. This helps prevent pulmonary embolism and promotes overall recovery.

Pneumatic compression, a treatment that uses thigh-high or calf-high compression stockings that automatically inflate with air and deflate every few minutes, can massage and squeeze the veins in the legs, improving blood flow.

Prevention while traveling

Prevention while traveling involves taking precautions to reduce the risk of blood clots, which are more common during long-haul travel. If you have risk factors for blood clots or are concerned about travel, it’s essential to consult your doctor for personalized advice.

Here are some recommended strategies to prevent blood clots during travel:

• Stay hydrated: 1. Drink plenty of fluids, especially water, to prevent dehydration, which can contribute to blood clot formation. Avoid alcohol, as it can lead to fluid loss.
• Move around: 2. Take breaks from sitting regularly. Move around the airplane cabin every hour or so, or if you’re driving, stop every few minutes and walk around the car a couple of times. Do some deep knee bends to stretch your legs.
• Fidget in your seat: 3. Keep your legs moving by fidgeting in your seat. Flex your ankles every 15 to 30 minutes.
• Wear support stockings: 4. Your doctor may recommend wearing support stockings to promote circulation and fluid movement in your legs. Compression stockings are available in various stylish colors and textures, and there are even stocking butlers to help you put them on.

Diagnosis

Pulmonary embolism diagnosis can be challenging, especially in individuals with underlying heart or lung conditions. Consequently, your doctor will likely review your medical history, perform a physical examination, and order one or more of the following tests:

• Blood tests: D-dimer, a clot-dissolving substance. High levels may indicate an increased risk of blood clots, although other factors can also cause elevated D-dimer levels. Blood tests can also measure oxygen and carbon dioxide levels in your blood. A clot in a lung blood vessel can lower oxygen levels. Additionally, blood tests may be conducted to determine if you have an inherited clotting disorder.
• Chest X-ray: This non-invasive test provides images of your heart and lungs on film. While X-rays cannot diagnose pulmonary embolism and may even appear normal when present, they can rule out conditions that mimic the disease.
• Ultrasound: A non-invasive test called duplex ultrasonography, sometimes called duplex scan or compression ultrasonography, uses sound waves to scan your thigh, knee, calf, and sometimes your arms to detect deep vein blood clots. A wand-shaped device called a transducer is moved over your skin, directing sound waves to the veins being tested. These waves are then reflected back to the transducer, creating a moving image on a computer. The absence of clots reduces the likelihood of deep vein thrombosis. If clots are present, treatment is likely initiated immediately.
• CT pulmonary angiography (CTPA): CT scanning generates X-rays to create cross-sectional images of your body. CTPA, also known as CT pulmonary embolism study, produces 3D images that can detect abnormalities such as pulmonary embolism within the arteries in your lungs. In some cases, contrast material is administered intravenously during the CT scan to outline the pulmonary arteries.
• Ventilation-perfusion scan (V/Q scan): When radiation exposure or contrast from a CT scan is a concern due to a medical condition, a V/Q scan may be performed. In this test, a tracer is injected into a vein in your arm, mapping blood flow (perfusion) and comparing it to lung airflow (ventilation). This helps determine if blo