What is pleural effusion?
Pleural effusion (PE) is the collection of fluid between the lung membranes (pleura). There are two membranes that surround the lungs. The membrane just outside the lung is called the visceral pleura, and the membrane just below the rib cage is called the parietal pleura. The part between the two pleura is called the pleural space. There is very little fluid in the pleural cavity, which is considered physiological. This fluid reduces friction between the pleural surfaces while breathing. The fluid in the pleural cavity has a dynamic property. On the one hand, there is fluid passage into the pleural space, and on the other hand, fluid is reabsorbed from the pleural space. Both fluid secretion and fluid absorption occur primarily in the parietal pleura.
How does a pleural effusion occur?
Fluid collects in the pleural space after a problem occurs in the balance (release or absorption or both) of the found fluid in the pleural space. The main causes of fluid formation in the pleural space are;
1- Diseases of the pleura itself
2-The formation of pressure changes between the fluid in the pleural space and the blood in the pleural vessels
3- Disruptions in lymphatic drainage
As an example of PE developing due to pleural diseases; PE developed due to tuberculosis (tuberculosis pleurisy), fluid formed after cancer metastasis to the pleura (malignant pleural effusion), pleural effusion (parapneumonic PE) accompanying pneumonia (pneumonia) can be given.
As an example of PE formed after pressure changes; PE in congestive heart failure (CHF) and PE in hypoalbuminemia (low albumin in the blood) can be given.
As an example of PE developing due to lymphatic drainage disorder; PE due to lymphomas involving the mediastinum (anatomical region between the right and left lung) can be given. Furthermore, in diseases of the pleura itself (eg, tuberculous pleurisy), obstruction in the lymphatic stomata (pore) in the pleura also contributes to the formation of PE.
What are the symptoms of pleural effusion?
The most common symptoms in patients with PE are chest pain, shortness of breath, and cough. Pain occurs on the side with PE. This pain is usually a stabbing pain that feels like a knife stabbing while breathing. This pain is called pleuritic chest pain. The pain is evident when the fluid is forming or decreasing, as the fluid increases, the pain decreases. In cases of excess pleural fluid, shortness of breath may occur. The cough accompanying PE is usually mild or moderate, and may occur with (deep) breathing. In addition to the above symptoms, there may be symptoms related to the cause of PE. For example; Parapneumonic PEs may present with fever, malaise, malaise, fatigue and general condition deterioration. Again, fever, fatigue, night sweats and weight loss may occur in tuberculous pleurisy. Dyspnea, dyspnea in supine position (orthopnea), frothy sputum, palpitations and edema of the legs (pretibial edema) may be present in CHF.
How is pleural effusion detected?
A significant portion of PEs can be detected by chest X-ray. If the amount of fluid is low or the PE is sub-pulmonic (below the lung), PE may not be detected on chest X-ray. In such cases, PE can be revealed by thoracic CT or ultrasonography.
Is there a cure for pleural effusion?
The treatment of PE is closely related to the disease causing PE. PE may occur due to many diseases, so the cause of PE must be determined in a patient with PE.
For example, treatment in tuberculous pleurisy is antituberculous drug therapy lasting at least 6 months.
How is the cause of pleural effusion investigated?
Thoracentesis (removal of fluid from the pleural space) is usually performed under ultrasound guidance. The fluid taken is examined biochemically. After the biochemical examination of the pleural fluid, cytological or microbiological examination is performed in cases deemed necessary. Again, in cases deemed necessary, biopsy is taken from the parietal pleura and histopathological examination is performed.
What is the treatment of pleural effusion?
In a patient with PE, once the cause of PE is determined, it is treated according to the underlying disease.
In patients with parapneumonic PE with thoracentesis indication, the patient’s treatment is planned considering the pleural fluid results obtained by thoracentesis.
As mentioned above, tuberculous pleurisy is treated with antituberculous drug therapy lasting at least 6 months.
Some diseases that cause PE may not have a cure. For example, PE (malignant PE) that occurs after cancer metastasis to the pleura usually occurs in advanced cancer cases. Treatment of such cases is usually palliative; It is aimed at reducing the symptoms of the disease, especially shortness of breath and increasing the quality of life. In cases deemed necessary, pleural membranes are adhered to prevent fluid collection by a process called pleurodesis.