Type of effusion
The most common symptom that occurs in the course of a pleural effusion is shortness of breath (dyspnoea), which occurs mainly during physical exertion. In addition, an elevated temperature up to fever frequently occurs. Some patients also report a feeling of tightness in the chest.
The extent of the symptoms increases with the amount of fluid accumulated and also depends on the cause of the effusion. In most cases, the symptoms do not severely restrict the patient’s general condition. Smaller effusions with a fluid accumulation of up to about 500 milliliters usually do not become symptomatic.
If the pleural effusion occurs within a short period of time, it is usually accompanied by (more severe) breathing difficulties. However, if the effusion occurs gradually, shortness of breath only occurs after some time, when a lot of fluid has already accumulated in the pleural gap. If there is a suspicion of a pleural effusion from a medical point of view, the attending physician starts tapping and listening to the airways.
A muffled tapping sound (especially at the lower lung borders) and reduced breathing sounds indicate fluid accumulation. If the suspicion is substantiated, an ultrasound examination will follow, in which the pleural gap will be visited and, in the case of pleural effusion, an increased accumulation of fluid will be visible. In a standing patient, the fluid accumulates between the underside of the lung and the diaphragm.
This manifests itself in ultrasound as a so-called echo-free substance – a black accumulation is visible. If the ultrasound examination is not sufficient to make a diagnosis, an X-ray of the thorax (detectable from amounts of 250-300 ml) or a computer tomography can be added. Since the cause of the pleural effusion always has to be clarified, the next step is a puncture of the pleural effusion, so that a sample of the fluid can be obtained, which can then be examined in the laboratory, so that the cause of the pleural effusion can be determined and the underlying disease can be treated.
The puncture is performed under ultrasound control, so that the doctor performing the procedure does not inadvertently penetrate the lung during the puncture. For the puncture, a fine needle is inserted in the area of the lower ribs and fluid is withdrawn via the puncture needle. The color and consistency of the fluid alone can provide initial information about the cause.
A bloody fluid, for example, is more likely to indicate a malignant cause. The protein content, weight and cell content are then determined in the laboratory. In the case of cells, particular attention is paid to inflammatory and tumor cells.
During the puncture, the doctor should pay particular attention to sterile working conditions, as otherwise environmental germs can enter the thorax and lead to a pleural empyema, for example. If the puncture does not provide information about the cause of the pleural effusion, a so-called thoracoscopy can be performed as a last resort. Thoracoscopy is a surgical examination in which a camera system is inserted into the thorax through a skin incision. A gas (usually carbon dioxide) is used to expand the layers of the pleura so that they are easily visible.
