bibasilar definition

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

The lobes of the lungs are filled with millions of tiny air sacs called alveoli. The alveoli 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 bibasilar atelectasis life-threatening in some cases.

Bibasilar atelectasis can also leave behind scarring, which could lead to reduced lung function afterward.

The condition is more common after major surgery, but may also be a complication of other issues.

The condition is sometimes confused with pneumothorax. While the two conditions are similar, they have different causes. In some cases, pneumothorax may lead to atelectasis on one side.

Symptoms

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

• shortness of breath
• feeling their breath is too shallow or quick
• not being able to take a full, satisfying breath
• coughing
• wheezing
• lots of mucus or sputum

Difficulty breathing is the most common symptom. A person may have other symptoms as well, depending on the underlying cause.

Causes

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It is most common for a person to experience bibasilar atelectasis after they have undergone a major surgical procedure, involving general 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 bibasilar atelectasis.
• Mucus plug: After chest or lung surgery, 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.

Things 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 normal 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 known as the pleural space. This can put too much pressure on the lung, causing it to collapse.
• Pneumonia: Lung infections, such as pneumonia, may cause a collapse due to inflammation.
• Scar tissue: Scarring in the lungs can come 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.
• Drugs: Some opioids or sedative drugs may put a person at risk for atelectasis, especially if they use large amounts of these substance.

Atelectasis is often confused with pneumothorax, so a thorough diagnosis is necessary. Doctors may do 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, they will usually order a chest X-ray, ultrasound, or computed tomography (CT) scan to confirm their diagnosis.

A doctor may also perform a bronchoscopy. This procedure is when they insert a tube through a person’s nose or mouth to get a closer look at their airways.

Treatment

How doctors treat bibasilar atelectasis depends largely on what has caused 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.

For instance, if a person has a tumor, they may require radiation therapy, surgery, or chemotherapy.

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

• pneumonia
• hypoxia or when the blood does not carry enough oxygen
• respiratory failure, which can be life-threatening
• scar tissue

Complications

The complications of bibasilar atelectasis can become serious if not treated by your doctor or a medical professional. The following are some possible complications of bibasilar atelectasis:

• Hypoxemia. This is when there are low oxygen levels in your blood.
• Pneumonia. Pneumonia can be both a cause as well as a complication that develops with this condition.
• Respiratory failure. Most bibasilar atelectasis is treatable. However, if you have lung disease or a full lung is lost due to the condition, you can go into respiratory failure. This can be life-threatening.

How is it treated?

Treatment for bibasilar atelectasis is based on what’s causing it. If the cause is a blockage, then that blockage will be removed with medication, suctioning, or sometimes surgery. Your doctor may need to suction out excess mucus to allow you to take deep breaths and clear up your lungs. An obstruction like a tumor may need to be treated with chemotherapy, radiation, or other medications.

Once the cause is treated, you may need additional treatments to help with your symptoms until they’re cleared. These additional treatments may include extra oxygen or antibiotics to clear up any infections.

How is it diagnosed?

If you have one of the causes or risk factors, your doctor may want to check your lungs or oxygen level periodically.

An X-ray of your chest will confirm the diagnosis. Once diagnosed your doctor may perform additional tests to find out what’s causing the condition. These additional tests may include a CT scan or bronchoscopy. A bronchoscopy is when your doctor views your lungs through a viewing tube into your bronchus.