Atelectasis

Atelectasis is a potentially serious lung condition that can be mild or severe. It is a collapsing of the lungs or parts of the lungs, called lobes that results in an inability to inflate and to circulate enough oxygen through the blood stream. Other possible complications include pneumonia and respiratory failure.

There are many things that can cause atelectasis, including blockages like tumors in the airways. Asbestos is a known cause of one particular type of atelectasis in which the lung tissue folds. Complications of mesothelioma, like pleural effusion, may also trigger atelectasis. Atelectasis is not typically fatal, but treatment is important to improve symptoms and quality of life.

What is Atelectasis?

Atelectasis occurs when a lung or part of a lung, called a lobe, collapses and cannot expand. The collapse may be partial or complete. Very small air sacs inside the lungs, called alveoli get deflated when this condition occurs, or they become filled with fluid. When there is complete collapse of one lung a person will experience symptoms, but when smaller areas are affected or the collapse is not complete there may be no signs that anything is wrong.

Symptoms

Not everyone who has atelectasis will have symptoms. The more severe the blockage, the collapse, or the greater the area of the lung affected, the more likely there are to be noticeable symptoms. These may include:

• Trouble breathing and taking deep breaths.
• Shallow, rapid breathing.
• A persistent cough.
• Wheezing.
• Elevated heart rate.
• Cyanosis, a blue tint to the skin caused by decreased oxygen in the blood.

Types of Atelectasis

There are a few different classifications for this condition based on the cause of the collapse and other factors. Obstructive atelectasis occurs when there is some kind of blockage or obstruction that prevents inflation in the lung or part of the lung. This is the most common type. Nonobstructive atelectasis can be caused by various issues, but is not triggered by an obstruction.

Middle lobe syndrome is a type of atelectasis that affects the middle lobe of the lung. It is either fixed or it recurs, and it is caused by inflammation or defects in the bronchial tissue. Rounded atelectasis occurs when the affected lung tissue folds and adheres to the pleura. This is the type of atelectasis that is most strongly connected to asbestos exposure. It can easily be misdiagnosed as a tumor.

Causes of Atelectasis

There are many potential causes of atelectasis. If it is an issue of obstruction, it may be a mucus plug, a foreign object, a tumor, a swollen lymph node, or an aneurysm. Pleural effusion, a common complication of mesothelioma that causes a buildup of fluid between the pleural tissues, can also put pressure on airways causing atelectasis.

Nonobstructive causes of atelectasis include injury to the chest or lungs, pneumonia, and tumors that don’t cause blockages but do cause the lung to deflate. Air leaking into the space between the lungs and the chest wall, called pneumothorax, can also trigger atelectasis. Scarring in the lung tissue, which can result from asbestos exposure, may also cause this condition.

Diagnosing Atelectasis

To diagnose atelectasis requires a complete physical examination followed by imaging of the chest cavity. The first step is usually to do an X-ray, which may show the obstruction and will show that there is an area of tissue with no air in it. A CT scan is the next stage in a diagnosis, as this can show doctors the soft tissue so that the cause of deflation of the lung can be seen. A bronchoscopy may also be needed, which is a small camera used to view the inside of the airways.

A biopsy is not commonly done as part of the diagnosis of atelectasis. However, in cases in which the imaging scans show a mass or growth a biopsy can determine if it is a cancerous tumor or a benign growth. A biopsy may be especially useful in the case of rounded atelectasis, the type caused by asbestos. The mass created by this condition may look like a tumor or hide tumors that may indicate the person also has mesothelioma. A biopsy helps refine the diagnosis.

Atelectasis and Asbestos Exposure

Rounded atelectasis is not a common type of this condition, but it is the one most strongly linked to asbestos exposure.  Estimates are that 30 to 86 percent of diagnosed cases are related to asbestos. This type of atelectasis occurs when fibrous pleural tissue catches part of the lung tissue, causing it to draw in. This is fairly easy to diagnose because it has a characteristic appearance in imaging: a round mass of pleura that has lung tissue radiating out from it. Even though it has a distinct look on radiographic imaging tests, it can be mistaken for a tumor.

The asbestos-related atelectasis doesn’t typically cause symptoms, but some people may experience shortness of breath or a dry cough. It is often stable, meaning it doesn’t get worse with time, but for some patients it will progress slowly over time. Rounded atelectasis is known to be associated with asbestos, but it is the rarest of the diseases caused by exposure.

Asbestos exposure can also trigger other conditions that in turn cause atelectasis. For instance, asbestosis is scarring of the lung tissue caused by asbestos fibers. This hardening tissue can put pressure on the airways and cause atelectasis. Pleural effusion, the buildup of fluid in the pleura, can also cause atelectasis and is a common side effect of pleural mesothelioma.

Treating and Managing Atelectasis

The treatment used for atelectasis depends on the underlying cause. For instance, if there is a tumor or other blockage, any treatment to remove it will relieve the condition. Surgery is a common treatment for removing obstructions. Surgery is usually followed by chest therapy to help the patient learn deep breathing exercises that will help inflate the lung tissue again.

For someone with mesothelioma or pleural effusion that is triggering atelectasis, treatment may involve surgery, chemotherapy or radiation to remove and shrink tumors, and draining of the fluid between the pleura. Rounded atelectasis is not usually treated surgically unless it is causing significant impairment or severe symptoms.

If you have been exposed to asbestos you may develop atelectasis, but you may also not have any symptoms. Make sure your doctor knows that you were around asbestos and consider getting screened for all asbestos-related conditions. Early diagnosis will give you more treatment options and a better overall prognosis.