Bibasilar atelectasis is when there is a collapse in the bottom part of both lungs. It can cause symptoms such as shortness of breath, coughing, wheezing, and more.

Atelectasis is a partial or total collapse of one or both lungs. It may occur for a number of reasons.

For example, when something pushes against the tiny air sacs in the lungs, or alveoli, and causes them to collapse. It may also occur when the oxygen and carbon dioxide in the alveoli move into the bloodstream and no new air moves in, due to an obstruction in the small airways, for example.

It may also result from impaired pulmonary surfactant production or function. Pulmonary surfactant is a fluid that helps prevent the alveoli from collapsing.

Bibasilar atelectasis can cause severe complications if left untreated. How doctors treat it will vary based on what has caused the collapse.

This article explores the causes, symptoms, and possible complications of bibasilar atelectasis. It also discusses how doctors diagnose and treat the condition.

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A person’s lungs comprise several areas that healthcare professionals call lobes. The right lung has three lobes, and the left lung has two lobes.

When someone experiences bibasilar atelectasis, the lowermost lobes of their lungs collapse entirely or partially.

The lobes of the lungs are filled with alveoli, which are arranged in clusters and surrounded by blood vessels. When a person breathes in and out, the alveoli allow their blood to collect oxygen and get rid of carbon dioxide.

During bibasilar atelectasis, the alveoli in the base of the lungs deflate and stop performing this essential task. Oxygen may not be able to reach the vital organs, making the condition life-threatening in some cases.

It can also cause scarring, which could lead to reduced lung function afterward.

According to the American Lung Association (ALA), people may confuse atelectasis with pneumothorax. This is because some people also refer to pneumothorax as a “collapsed lung”. While the two conditions are similar, they have different causes.

In some cases, pneumothorax may lead to atelectasis on one side.

If only a small portion of the lung collapses, bibasilar atelectasis may not cause any symptoms. If a person does experience symptoms, these may include:

A person may have other symptoms as well, depending on the underlying cause.

Older research from 2014 suggests that bibasilar atelectasis is more common after major surgery and anesthesia.

There is a range of other possible causes, as well. Doctors class these causes as either obstructive or nonobstructive.

Obstructive causes

A person may experience obstructive atelectasis when something blocks their airway and prevents their lung from filling correctly. This can occur for a variety of reasons, including:

  • Foreign object: If someone inhales or improperly swallows a foreign object, it can obstruct their airflow and cause atelectasis.
  • Mucus plug: After chest or lung surgery, healthcare professionals advise many people are advised not to cough to avoid stressing the lungs. Not coughing can cause a buildup of mucus in the lungs, which may block the airways. Sometimes, a doctor will suction out this buildup after surgery, but it can continue to accumulate while a person is recovering. Other conditions, including asthma and cystic fibrosis, may also lead to mucus plugs.
  • Tumor: A tumor can narrow or completely block off the airway.
  • Blood clot: Significant bleeding in the lungs may build up and cause a blood clot. A clot can block the airway and cut off the flow of oxygen, collapsing a lobe or lung.
  • Narrowing of the airways: When a person has a severe disease, its progression can lead to narrowing of their airways, eventually causing a collapse. Chronic infections can also cause inflammation and scarring, constricting the main airways.

Nonobstructive causes

Pressure rather than a blockage causes nonobstructive atelectasis.

Factors that can put pressure on the lungs and make it hard for them to fill up include:

  • Anesthesia: The use of anesthesia during surgery may cause bibasilar atelectasis. Anesthesia changes a person’s regular breathing pattern. The usual gas exchange in their body may also be affected. This combination could lead to alveoli collapsing.
  • Pleural effusion: Excess fluid can build up in the cavity between the lung and the chest, or pleural space. This can put too much pressure on the lung, causing it to collapse.
  • Lung infections: Various infections may cause a collapse due to inflammation.
  • Scar tissue: Scarring in the lungs can result from surgery, lung diseases, or inhaling harmful chemicals. Scar tissue can permanently damage the lungs and could lead to a lung collapse.
  • Trauma: When a person suffers a chest injury from a traumatic event, such as a car crash, it could make their breathing difficult and compress their lungs.
  • Pneumothorax: Air that leaks into the pleural space can put pressure on the lungs, making it hard for them to inflate. This pressure can lead to a collapse of one or more lobes.
  • Tumor: A tumor that is not near the airway may put pressure on the lung as it grows. This pressure may collapse the lobe or the entire lung.
  • Certain drugs: Some opioids or sedative drugs may put a person at risk for atelectasis, especially if they use large amounts of these substances.

According to the ALA, atelectasis and pneumothorax are similar, so a thorough diagnosis is necessary. Doctors may conduct a physical exam and may also want to monitor a person’s oxygen levels or lung function periodically to note any changes.

If they suspect atelectasis, healthcare professionals may order a chest X-ray, ultrasound, or CT scan to confirm their diagnosis.

A doctor may also perform a fiberoptic bronchoscopy. This procedure involves a healthcare professional inserting a tube through a person’s nose or mouth to get a closer look at their airways.

How doctors treat bibasilar atelectasis depends largely on the underlying cause of the collapse.

To treat blockages, they will first try to remove the obstruction, using methods such as suction, drainage, or chest percussion. Some medications may also help break up and expel fluids.

To treat causes related to pressure, doctors will relieve the pressure in the lung and allow it to expand fully. This should restore function in the lungs.

When surgery causes atelectasis, doctors may recommend therapies to allow the lungs to expand naturally. They may tell a person to do deep breathing exercises, walk around after surgery to increase their breathing, and gently cough up mucus if possible.

Healthcare professionals will treat lung conditions or medical conditions causing atelectasis to help prevent further collapse. For instance, if a person has a tumor, they may require radiation therapy, surgery, or chemotherapy.

Early treatment of bibasilar atelectasis may improve a person’s outlook and prevent the risk of complications.

If there is extensive damage to the lungs or the collapse is not treated urgently, possible complications can include:

Older research from 2014 suggests that many people experience bibasilar atelectasis while they are still in the hospital and recovering from surgery.

If a person is already in the hospital, this can make diagnosis and treatment easier, and may help prevent complications.

In cases where a person notices symptoms when they are no longer in the hospital, it is crucial for them to visit a doctor urgently for treatment.

However, a person’s outlook may depend on the underlying cause of atelectasis.

Bibasilar atelectasis describes a collapse in the lower lobes of both lungs. It may cause shortness of breath and rapid, shallow breathing, as well as other symptoms.

Older research from 2014 suggests that bibasilar atelectasis is more frequent following major surgery and anesthesia. However, a range of factors may cause it, including a foreign object in the lungs or pleural effusion.

Treatment will depend on the underlying cause of bibasilar atelectasis. A person should contact a healthcare professional as soon as possible if they experience any symptoms of the condition.