Diagnostic measures for the detection of a pulmonary embolism
In order to detect a pulmonary embolism at an early stage, it is important to know the symptoms and learn to recognise them in oneself. Only patients who know how a pulmonary embolism can present itself can consult a doctor in good time if the symptoms are early. The physical symptoms are therefore the main focus of early detection.
In the event of sudden onset of respiratory distress, possibly accompanied by chest pain and swelling of one leg, it is essential to visit a hospital as soon as possible. There further diagnostics can then be carried out. The timely visit to a hospital is crucial for the success of the therapy.
Even if a thrombosis is suspected, a doctor should be consulted early on so that the blood clot in the leg can be treated professionally. In this way, the development of a pulmonary embolism can be prevented. If pulmonary embolism is suspected, a computed tomography (CT) scan can be performed in hospital.
This is the fastest method of confirming the diagnosis. The patient is placed in a kind of tube that uses X-rays to take cross-sectional images of the body.To make the blood clot in the pulmonary vessels particularly visible, the patient is injected with a contrast medium before the examination. The extent and location of the pulmonary embolism can then be determined on the images.
Small embolisms may be overlooked in computed tomography under certain circumstances. However, they can be made visible by means of pulmonary scintigraphy. If pulmonary embolism is suspected, an ECG is usually written at an early stage.
For this purpose, various electrodes are attached to the patient’s chest in a specific arrangement. The electrodes divert the electrical currents over the heart. These are recorded on a paper in the form of a curve, which gives the doctor information about the state of the excitation conduction of the heart muscle.
In the case of a pulmonary embolism, there are typical signs in the ECG that indicate this condition. This is known as the SIQIII type. This designation refers to a special form of the ECG curve, which has S-waves in the first lead and Q-waves in the third lead.
In addition, in the case of a pulmonary embolism, the ECG often shows a fast heartbeat (tachycardia) and cardiac arrhythmia. A conventional chest x-ray is a less important method for the diagnosis of pulmonary embolism, since a CT scan of the thorax can usually provide much more specific information. Sometimes an X-ray of the thorax is initially taken to rule out other causes of the symptoms.
However, if the suspicion of a pulmonary embolism is confirmed, a CT scan of the chest is usually taken in addition. Signs of a pulmonary embolism that could possibly be detected on a chest x-ray include pleural effusion as a sign of increased vascular permeability in the event of blood congestion, an enlargement of the heart shadow due to increased right-heart strain and various signs of a pulmonary infarction if the reduced blood flow has already caused the death of lung tissue. These changes may also occur in other diseases, so that the final detection of a clot in a pulmonary embolism is usually only possible with a high degree of certainty by means of CT angiography.
In order to further confirm the diagnosis of pulmonary embolism, a blood count can also be taken. This is examined for the so-called D-dimers. These are cleavage products of fibrin, which is found in blood clots.
If the body is busy breaking down such a thrombus, as in the case of a pulmonary embolism, the D-dimers in the blood are elevated. With normal D-dimers in the blood, pulmonary embolism can be ruled out with great certainty. Furthermore, a magnetic resonance imaging (MRI) or an angiography of the pulmonary tract can be performed to diagnose a pulmonary embolism.
