Causes and Symptoms of Pleural Effusions
Pleural effusion is an accumulation of fluid between the membranes lining the lungs and the chest cavity. Many diseases and medical conditions can cause pleural effusions, including congestive heart failure, pneumonia, infections, kidney disease, rheumatoid arthritis and tuberculosis. It can also occur as a result of asbestos exposure, presumably due to inflammation caused by asbestos and the diseases it leads to.
Though not as common as other asbestos-disease-related side effects such as pleural thickening and pleural plaques, pleural effusions can cause pain or extreme discomfort. They can also be a sign of a serious disease such as asbestosis (pulmonary fibrosis) or malignant mesothelioma. If you believe a past employer or other party is responsible for your exposure to asbestos and the effects it has had on your health, you should consider speaking with a mesothelioma lawyer. An experienced attorney will be able to evaluate your case and determine your chances of reaching a settlement or receiving financial compensation in the form of a court award.
Causes of Pleural Effusion
The mesothelia, or membranes that surround the body's major organs, contain cells that produce small amounts of fluid that acts as a lubricant, allowing the organs to rub up against each other without causing damage.
Two examples of mesothelia are the pleurae the mesothelia that encase the lungs (visceral pleura) and chest cavity (parietal pleura), which come into contact with one another during the expansion and contraction of the lungs. The fluid that fills the space between the visceral pleura and parietal pleura is called pleural fluid.
When the proper level of pleural fluid is being produced, it is easily absorbed by capillaries and lymph nodes. However, certain medical conditions, including pleural thickening, asbestosis and malignant mesothelioma, can cause the pleurae to produce too much fluid: this is called pleural effusion.
There are two types of pleural fluid exudative and transudative and thus two types of pleural effusion: transudative pleural effusion and exudative pleural effusion. The latter is often caused by asbestosis and asbestos lung cancer, or mesothelioma. These diseases can lead to irritation, swelling and inflammation, which in turn causes the blood vessels in the pleurae to leak extra fluid into the pleural space. When examined under a microscope, exudative fluid can be identified by its viscosity (thick, sticky consistency) and cloudy appearance.
Pleural Effusion Symptoms
Though some asbestosis and pleural mesothelioma patients with pleural effusions experience no symptoms at all, others may experience any of the following:
- Chest pain
- Chest pressure
- Shortness of breath (dyspnea)
- Rapid breathing
Symptoms involving the chest and breathing can also be caused by other side effects of asbestos diseases, including pleural thickening. As a result, pleural effusions sometimes go unnoticed or undiagnosed until discovered in a chest X-ray.
Diagnosis and Tests for Pleural Effusion
Pleural effusions are often discovered by doctors attempting to determine the source of a patient's symptoms. For example, a doctor examining a patient with a stethoscope may notice soft breathing or a dull sound when tapping the patient's chest.
If a doctor suspects the existence of a pleural effusion, he or she may order X-rays to confirm the diagnosis and determine how much fluid is present in the pleural space. If congestive heart failure has been ruled out, the doctor may then perform a procedure called thoracentesis to extract a small sample of the pleural fluid for analysis. Also known as pleural fluid aspiration, this relatively painless procedure is done by inserting a needle between the ribs to access the pleural space. The fluid is then extracted and examined under a microscope to look for cancerous cells, bacteria and a protein called mesothelin. New research suggests that high levels of mesothelin may indicate mesothelioma.
Ultrasound and/or a thoracic CT scan (CT scan of the chest) may also be ordered to diagnose pleural effusions.
Pleural Effusion Complications
Complications of pleural effusions include collapse of the lung; pneumothorax, or air in the chest cavity, which is a common side effect of the thoracentesis procedure; and empyemas (abscesses) caused by infection of the pleural fluid, which require drainage of the fluid.
Pleural effusion can place patients with asbestosis or mesothelioma at even more risk than other patients if it leads to difficulty breathing. This is because patients with these conditions so often suffer from pleural scarring, which itself makes it extremely difficult to breathe. Pleural effusion can exacerbate this problem, and ultimately the inability to breathe properly can contribute significantly to the patient's downward spiral.
Pleural Effusion Treatment
In some cases, no treatment is required for pleural effusions. However, when doctors link the fluid build-up to a patient's discomfort or pain or to other, more serious side effects they often take measures to address the cause and/or effects of the effusion. As previously mentioned, a patient suffering from asbestosis or mesothelioma may experience more than one condition that makes it difficult to breathe. To address this, doctors do whatever they can to treat the root causes.
For patients with pleural-effusion-related breathing problems, this may include the following:
Thoracentesis. Further extraction of pleural fluid can alleviate pressure in the chest, making it easier to breathe.
Chemical pleurodesis. This procedure involves the insertion of agents such as talc or bleomycin to eliminate the pleural space altogether, so that fluid can no longer build up.
Pleural decortication. Also called pleurectomy, this surgery removes the pleura; like chemical pleurodesis, pleural decortication eliminates the pleural space, thereby preventing pleural fluid from building up.
For more information on mesothelioma symptoms and other issues related to asbestos exposure, asbestosis and malignant mesothelioma, please refer to other articles on our site. If you or a family member has been diagnosed with an asbestos-related disease, contact a mesothelioma attorney as soon as possible.
[Page updated November 2009]