In the case of a pulmonary embolism, a pulmonary artery suddenly becomes blocked. In the vast majority of cases, the causative embolus (propelled particle) is a blood clot. These blood clots usually originate from a thrombosis of the deep veins of the leg. Depending on the size of the clot, the pulmonary embolism can be asymptomatic (without any symptoms) or severe. Signs of a severe course are pain in the chest area, shortness of breath or even circulatory collapse.
If a bilateral pulmonary embolism occurs, there is a high risk of death. In Germany alone, 7000 people die every year from a pulmonary embolism. Old people between the ages of 80 and 85 are particularly affected. There is also a greater risk of embolism during pregnancy or when taking the contraceptive pill in combination with nicotine abuse.
The difference between a thrombosis and an embolism is as follows:
- Thrombus: a blood clot continues to grow and eventually leads to blockage of the vessel at this point (thrombosis)
- Embolus: A particle that reaches other parts of the body via the bloodstream and blocks a vessel there (embolism). The carried particles can be blood clots, fat, air or, in rare cases, amniotic fluid.
In simple terms, this means that the thrombosis occurs on the spot, usually in veins, but sometimes also in previously damaged arteries. Embolism refers to a process that occurs elsewhere and leads to particles (embolus) being carried along with the bloodstream.
A blood clot closes a (in this case pathologically narrowed) vessel
Pulmonary embolism usually occurs as a result of a thrombosis in the deep veins of the leg. Parts of the thrombosis are then transported with the blood flow from the leg into the right heart and from there into the lungs. The embolus in this case is therefore the thrombosis or clot that detaches from it. This is also referred to as a thromboembolism. Depending on the size of the detached clot, the symptoms of a pulmonary embolism can be very pronounced or barely present or non-existent.
Yes, in rare cases a fat embolism can occur, for example during childbirth due to a so-called amniotic fluid embolism or as part of a major bone fracture operation. However, these forms of embolism are the exception. In the vast majority of cases, the embolism is the spread of blood clots(thromboembolism).
A general distinction is made between
- solid embolus: carried blood clots, parasites or tissue fragments. They are the cause of around 90 percent of all embolisms.
- gaseous embolus, for example air bubbles that form after open vascular injuries
- liquid embolus, such as fat droplets from damaged body tissue or amniotic fluid that penetrate the vessels after bone fractures (fat) or during the birth process (amniotic fluid)
Various risk factors can favor the development of a thrombus and thus a pulmonary embolism as a possible consequence. These include above all
- Long car or plane journeys
- Surgical interventions
- Restrictions on movement
- smoking
- Hormone replacement therapies
- being overweight
For this reason, high-risk patients are advised to wear medical compression stockings when traveling for long periods and, if necessary, to have a "thrombosis injection". In addition, breaks should always be taken to move around and activate the muscle pump.
A pulmonary embolism can be recognized by various signs. The type of symptoms depends on the extent of the blood clot that has been carried away. The exact area of the vascular occlusion also plays a role. Smaller pulmonary embolisms sometimes cause no symptoms at all. If, on the other hand, a larger pulmonary vessel is affected, this has a considerable impact on the blood flow between the heart and lungs, resulting in sudden symptoms. In the worst case, even life-threatening cardiovascular arrest is possible.
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Typical symptoms of a pulmonary embolism are
- Acceleration of breathing
- palpitations
- shortness of breath
- Pain within the chest
- a feeling of oppression
- anxiety
- sweating
- fainting
- a drop in blood pressure and circulatory shock
During the examination, the doctor will first take the patient's medical history. He will ask about the nature of the symptoms and possible risk factors. They will also carry out a physical examination.
The so-called Wells score plays an important role in the diagnosis. This is a scoring system named after the physician Philip S. Wells. It comprises seven parameters:
- is there evidence of deep vein thrombosis?
- Does the heart beat more than one hundred times per minute?
- Has the patient recently undergone an operation or been confined to bed?
- Has the patient previously suffered from a blood clot or pulmonary embolism?
- Is the patient coughing up blood or is there blood in the throat?
- Does the patient have cancer?
- Are other diagnoses likely?
One point is awarded per question. If other diagnoses are likely, two points are deducted. From a value of two, a thrombosis or pulmonary embolism is considered probable.
The treatment of 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 event of a severe pulmonary embolism that results in circulatory collapse, rapid life-sustaining measures are required. These include cardiac massage and the supply of pure oxygen through a nasogastric tube. Medication and fluids are administered via a vein. Further treatment takes place in the intensive care unit .
Risk groups can prevent the development of a pulmonary embolism. This includes, for example, taking blood-thinning medication such as coumarins. Another important measure is the permanent use of medical compression stockings. These counteract the build-up of blood in the legs and thus the formation of thrombi.
