A pulmonary embolism is an acute condition in which a blood clot in the lung can block a pulmonary artery. This clot often originates from a deep vein thrombosis, which significantly increases the risk of a pulmonary embolism. Depending on the size of the embolus, a pulmonary embolism can be life-threatening, especially if blood pressure drops during the event or if a severe acute pulmonary embolism is present. If symptoms such as sudden chest pain, shortness of breath, or circulatory problems occur, this is considered a sign of a pulmonary embolism, and medical help must be sought immediately. Diagnosis typically involves a physical examination, an ECG, laboratory tests, and imaging studies to assess the likelihood of a pulmonary embolism or to rule it out. Prompt treatment is crucial, as early therapy with anticoagulants reduces the risk of serious complications.
What is a pulmonary embolism?
A pulmonary embolism occurs when a pulmonary artery becomes suddenly blocked. In most cases, the embolus (a dislodged particle) is a blood clot. These blood clots usually originate from a deep vein thrombosis in the leg.
Depending on the size of the clot, a pulmonary embolism can be asymptomatic (without any symptoms) or severe.
Signs of a severe case include:
- Chest pain
- Shortness of breath or
- circulatory collapse
If a bilateral pulmonary embolism occurs, it poses a life-threatening risk. In Germany alone, 7,000 people die from pulmonary embolism each year.
Older adults between the ages of 80 and 85 are particularly at risk.
There is an increased risk of an embolism:
- During pregnancy or
- When taking the birth control pill in combination with nicotine
What is the difference between an embolism and a thrombosis?
The difference between thrombosis and embolism is as follows:
Thrombus: A blood clot continues to grow and eventually blocks the blood vessel at that site (thrombosis)
Embolus: A particle that travels through the bloodstream to other parts of the body and blocks a blood vessel there (embolism). These particles can be blood clots, fat, air, or, in rare cases, amniotic fluid.
Put simply, this means that thrombosis develops at the site itself, usually in veins, and sometimes also in pre-existing damaged arteries.
An embolism describes a process that originates elsewhere. This involves the transport of particles via the bloodstream.
A blood clot blocks a vessel (in this case, one that is pathologically narrowed) @ tussik /AdobeStock
Why is thrombosis often mentioned in connection with pulmonary embolism?
A pulmonary embolism usually develops as a result of a thrombosis in the deep veins of the leg.
Parts of the thrombus travel with the bloodstream from the leg into the right side of the heart. From there, they reach the lungs.
In this case, the embolus is therefore the thrombosis itself or the clots that break off from it.
Doctors also refer to this as a thromboembolism. Depending on the size of the detached clot, the symptoms of a pulmonary embolism can be very severe, mild, or virtually nonexistent.
Can a pulmonary embolism occur even without deep vein thrombosis in the leg?
Yes, in rare cases, a fat embolism can occur during childbirth due to an amniotic fluid embolism or during major surgery for a bone fracture.
However, these forms of embolism are the exception. In most cases, the embolism involves the transport of blood clots (thromboembolism).
In general, medical professionals distinguish between:
- solid emboli: displaced blood clots, parasites, or tissue fragments. They account for about 90 percent of all embolisms.
- gaseous emboli: for example, air bubbles that form after open vascular injuries
- liquid emboli: such as fat droplets from damaged body tissue or amniotic fluid that enters the blood vessels following bone fractures or during childbirth (amniotic fluid)
When am I at risk of developing a pulmonary embolism?
Various risk factors can increase the likelihood of a blood clot forming and, consequently, a pulmonary embolism.
These include, above all:
- Long car or plane trips
- Surgical procedures
- Limited mobility
- Smoking
- Hormone replacement therapy
- Being overweight
For this reason, high-risk patients should wear medical compression stockings during long trips.
If necessary, they should also administer a thrombosis injection. In addition, they should take frequent breaks to move around and activate the muscle pump.
How can you recognize a pulmonary embolism?
A pulmonary embolism manifests itself through various symptoms. The nature of the symptoms depends on the extent of the dislodged blood clot.
The location of the blockage also plays a role. For example, smaller pulmonary embolisms sometimes cause no symptoms at all.
If, on the other hand, a larger pulmonary vessel is affected, this has a significant impact on blood flow between the heart and lungs. Symptoms can then appear suddenly. In the worst-case scenario, a life-threatening cardiovascular arrest is even possible.
Woman with chest pain © Taras_Muroslavovuch /AdobeStock
Typical symptoms of a pulmonary embolism include:
- Rapid breathing
- Rapid heartbeat
- Shortness of breath
- Chest pain
- Feeling of tightness
- Anxiety
- Sweating
- Fainting
- Drop in blood pressure and circulatory shock
Diagnosis of a pulmonary embolism
During the examination, the doctor first reviews the patient’s medical history. The doctor asks about the nature of the symptoms and any possible risk factors. The doctor also performs a physical examination.
The Wells score plays a significant role in the diagnosis. This is a scoring system named after the physician Philip S. Wells.
It comprises seven parameters:
- Are there signs of deep vein thrombosis in the leg?
- Is the heart beating more than 100 times per minute?
- Has the patient recently undergone surgery or been on strict bed rest?
- Has the patient ever had a blood clot or a pulmonary embolism before?
- Is the patient coughing up blood or experiencing blood in the throat?
- Does the patient have cancer?
- Are other diagnoses likely?
Each question is worth one point. If other diagnoses are likely, the doctor subtracts two points. A score of two or higher indicates that a thrombosis or pulmonary embolism is likely.
Treatment of a Pulmonary Embolism
Treatment for a pulmonary embolism depends on its severity. The first step is to stabilize breathing and circulation. The doctor also administers a blood-thinning medication.
In the case of a severe pulmonary embolism that results in circulatory failure, rapid life-saving measures are required.
These include chest compressions and the administration of pure oxygen via a nasal cannula.
The patient receives medications and fluids through an IV. Further treatment takes place in the intensive care unit.
How can a pulmonary embolism be prevented?
High-risk groups can take steps to prevent a pulmonary embolism. This includes, for example, taking blood-thinning medications such as coumarins.
Another important measure is the consistent use of medical compression stockings. These help prevent blood from pooling in the legs and thus reduce the risk of blood clots forming.
FAQs on Pulmonary Embolism
How does a pulmonary embolism develop?
In most cases, a pulmonary embolism is caused by a blood clot that forms during deep vein thrombosis and then travels to the lungs. There, it can block a pulmonary artery and obstruct blood flow. An embolism is a common complication of venous thrombosis and pulmonary embolism and is considered a possible cause of a pulmonary embolism when typical symptoms occur.
What signs of a pulmonary embolism indicate a medical emergency?
Typical symptoms include sudden shortness of breath, chest pain, rapid heartbeat, dizziness, or a drop in blood pressure. If you experience symptoms such as sudden breathing difficulties—especially if you are at risk for a pulmonary embolism—you should seek medical help immediately.
What increases the risk of a pulmonary embolism?
The risk of a pulmonary embolism increases with prolonged sitting, immobility, surgical procedures, hormonal factors, obesity, or existing coagulation disorders. A previous deep vein thrombosis significantly increases the likelihood of a pulmonary embolism.
How is a pulmonary embolism diagnosed?
If a pulmonary embolism is suspected, the doctor first takes a medical history and assesses symptoms, checks vital signs, and performs tests such as an ECG and laboratory analyses. This is followed by imaging tests to more accurately assess the likelihood of a pulmonary embolism. If the embolism cannot be definitively confirmed, it can be largely ruled out through structured diagnostic procedures.
How is a pulmonary embolism treated?
Treatment for a pulmonary embolism begins with stabilizing respiration and circulation. Treatment with anticoagulants—usually heparin or direct oral anticoagulants—is then started immediately. The choice of therapy depends on the severity of the condition and the individual’s risk. The goal of treatment is to stabilize the clot, restore blood flow, and prevent further embolisms.
Why is prompt treatment so important for acute pulmonary embolism?
Acute pulmonary embolism can be life-threatening because it severely impairs circulation and leads to reduced organ perfusion. Prompt treatment reduces the risk of serious complications and significantly improves the management of acute pulmonary embolism.
What symptoms can occur months after a pulmonary embolism?
Some patients report persistent shortness of breath, chest tightness, or reduced exercise tolerance months after a pulmonary embolism. These symptoms may result from delayed lung recovery or post-thrombotic syndrome and should be evaluated by a doctor.
Share this article
About the medical author
Prof. Dr. med. Susanne Regus
Medical Author
Prof. Dr. med. Susanne Regus – medical author: expert articles, professional insights and medical expertise in the Leading Medicine Guide.
View full expert profile →Sources
https://herzmedizin.de/fuer-aerzte-und-fachpersonal/dgk/leitlinien/leitlinien-katalog/pocket-leitlinie-management-der-akuten-lungenembolie-version-2019
