Atelectasis

A complete or partial collapse of the lung, atelectasis may be mild or severe. Whether a collapse of the entire lung or an area (lobe) of the lung, the result is inability to inflate. With difficulty breathing, the body may be able to circulate enough oxygen through the blood stream. Other possible complications include pneumonia and respiratory failure.

There are many causes of atelectasis, including blockages like tumors in the airways. Asbestos is also a known cause of one particular type of atelectasis. In this type, the lung tissue folds causing a variety of symptoms. Complications of mesothelioma, like pleural effusion, may also trigger atelectasis. Atelectasis is not typically fatal, however treatment is important to relieve symptoms and improve quality of life.

What is Atelectasis?

Atelectasis occurs when a lung or part of a lung, called a lobe, collapses, inhibiting expansion. The collapse may be partial or complete. Very small air sacs inside the lungs, called alveoli deflate or become filled with fluid when this condition occurs. Complete collapse of one lung will cause a person to experience uncomfortable symptoms. However, no signs may be present when smaller areas are affected, or the collapse is not complete.

Symptoms

Not everyone who has atelectasis will have symptoms. The more severe the blockage or the greater the area of the lung affected, the more likely there are to be noticeable symptoms. Symptoms 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 several classifications for this condition based on the cause of the collapse as well as other factors. Obstructive atelectasis occurs when there is a blockage or obstruction preventing inflation in the lung or part of the lung. This is the most common type of atelactasis. A variety of issues cause nonobstructive atelectasis, but it is not triggered by an obstruction.

Middle lobe syndrome is a type of atelectasis affecting the middle lobe of the lung. It is either fixed or recurs, and 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 most strongly connected to asbestos exposure. Doctors can easily misdiagnose this type as a tumor.

Causes of Atelectasis

There are many potential causes of atelectasis. If caused by an obstructionobstruction, it may be a mucus plug, foreign object, tumor, swollen lymph node, or an aneurysm. Pleural effusion, a common complication of mesothelioma causing 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 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

Diagnosing atelectasis requires a complete physical examination followed by imaging of the chest cavity. The first step is usually an X-ray, which may show the obstruction as well as any tissue with no air in it. A CT scan is the next stage in a diagnosis, allowing doctors to see soft tissue and the cause of deflation. The patient may also need a bronchoscopy. A bronchoscopy involves a small camera used to view the inside of the airways.

Atelactasis does not typically require a biopsy. However, in cases where the imaging scans show a mass or growth, a biopsy can determine if it is a cancerous tumor or 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 it may hide tumors indicating the person also has mesothelioma. A biopsy helps refine the diagnosis.

Atelectasis and Asbestos Exposure

Rounded atelectasis is relatively uncommon, but is the condition most strongly linked to asbestos exposure.  It is estimated that 30 to 86 percent of diagnosed atelactasis cases are related to asbestos. Asbestos-related atelectasis occurs when fibrous pleural tissue catches part of the lung tissue, causing it to draw in. This is easy to diagnose due to its characteristic appearance in imaging. In imaging scans, this atelactasis appears as a round mass of pleura with lung tissue radiating from it. Doctors often mistake atelactasis for a tumor, in spite of its distinct appearance on radiographic imaging tests.

The asbestos-related atelectasis doesn’t typically cause symptoms, however some may experience shortness of breath or dry cough. It is often stable, meaning it does not worsen with time. For some patients, however, it will progress slowly over time. Rounded atelectasis is the rarest of the diseases caused by exposure, but is is often associated with asbestos.

Asbestos exposure can also trigger other conditions that in turn cause atelectasis. For instance, asbestosis is scarring of the lung tissue caused by inhaling asbestos fibers. This hardening of tissue can put pressure on airways causing 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

Treatment for atelectasis depends on the underlying cause. If there is a tumor or other blockage, procedures to remove it will relieve the condition. Surgery is a common treatment for obstruction removal. Chest therapy may follow surgery to help patients learn deep breathing exercises to re-inflate the lung tissue.

For someone with mesothelioma or pleural effusion triggering atelectasis, treatment may involve surgery, chemotherapy, or radiation to remove or shrink tumors, as well as drain the fluid between the pleura. Surgery is not typically used to treat rounded atelectasis unless it causes significant impairment or severe symptoms.

If you have been exposed to asbestos, you may develop atelectasis, but may not have symptoms. Tell your doctor you were exposed to asbestos and consider screening for asbestos-related conditions. Early diagnosis will increase your treatment options and give you a better prognosis.