A pulmonary embolism is the obstruction of a blood vessel in the lung. It is usually caused by a blood clot, the so-called thrombus, more rarely by gas bubbles, or by fat. Since pulmonary embolism is potentially life-threatening, first aid measures are always necessary. The falling blood pressure can lead to obstructive shock with circulatory arrest. Because of the increased pumping resistance in the pulmonary circulation (pulmonary hypertension), the right ventricle is subjected to greater stress, which can lead to heart failure. In Germany, between 40,000 and 100,000 people die of pulmonary embolism every year. This makes it the third most common cardiovascular disease leading to death after heart attack and stroke.
If detected in time, however, the prognosis is very good: in addition to the need for oxygen, lysis therapy is performed to dissolve the thrombus. Intravenously applied heparin is used to inhibit blood coagulation, which usually leads to the resolution of acute symptoms. In the case of clinical suspicion of pulmonary embolism, the diagnosis can be confirmed most quickly with contrast-enhanced computer tomography. This can also be used to differentiate between the most common differential diagnoses of heart attack, pneumonia, pneumothorax or aortic dissection. Since the diagnosis is extremely time-critical, algorithms that automatically detect pulmonary embolism have a high clinical and health policy relevance.