Airless Lung Atelectasis

Atelectasis is a condition in which part of the lung becomesairless and collapses.

What is going on in the body?

The lungs are divided into large sections called lobes.Each lobe is divided into smaller segments. Each of these segmentsis composed of thousands of small air cavities. These tiny spacesare called alveoli, and they look somewhat like a honeycomb. Eachalveoli is held open by complexwalls called alveolar walls. These walls, along with a substance calledsurfactant that is produced by the lung, help keep the alveoli open andfilled with air. When healthy people breathe, air travels all the way down thebronchial tubes to the alveoli. It is through these walls that gases likeoxygen are transferred into the blood. When the alveoli cannot stayopen, atelectasis occurs. When that happens, the lung cannotpass oxygen to the blood.

What are the causes and risks of the condition?

There are several types of atelectasis.

Obstructive atelectasis occurs when something preventsair from reaching the alveoli. This blockage may be caused by:

something stuck in the airway, such as a peanut or sunflower seed

diseases such as pneumonia,where mucous becomes thick

myasthenia gravis,an autoimmune disorder leading to episodes of muscle weakness

hypoventilation, a condition that occurs when there is a decrease in theusual amount of air that enters the lungs when a person breathes in. Thiscan be caused by shallow breathing, which is often the result ofchest pain.Decreased airflow to the lungs also can be a side effect ofanesthesiaafter surgery.

Compressive atelectasis results when the air passages areclosed from the outside. An enlarging lung tumor may press on theoutside of the larger bronchial tubes, resulting in partial or complete closure.

Adhesive or congenital atelectasis results from the lack ofsurfactant. Surfactant is a protein found naturally in the lungs that helps withgas exchange in the alveoli. It also helps keep the lungs elastic. This type ofatelectasis can be caused by congenital disorders such as hyalinemembrane disease. Without surfactant, the alveolar walls alone cannotkeep the alveoli open.

People are more at risk for atelectasis if they:

are obese

have a congenital lung disease, such as cystic fibrosis

have a neuromuscular disease, such as amyotrophic lateral sclerosis or multiple sclerosis

have chest trauma, such as a crush injury

have emphysema

What are the signs and symptoms of the condition?

Symptoms depend on how much of the lung is involved.A person may not even be aware of atelectasis if only a small part ofthe lung is affected. But, if a large part of the lung is involved, a personmay have these symptoms:

shortness of breath

fatiguewith minimal exertion

fever

chest painon the affected side

cyanosis,which is a blue color in the skin

How is the condition diagnosed?

Atelectasis is diagnosed by a person’s symptoms andthe physical exam findings. A chest x-ray that shows the airless part of the lung confirms the diagnosis. A chest CT scanmay help the doctor find the cause.

What can be done to prevent the condition?

In some cases, a person may be able to reduce his or her risk for this condition byexercising regularly and by not smoking or breathing in second-handsmoke.

Atelectasis can also be a complication of surgery.When possible, healthcare providers should:

have the person breathe on his or her own after surgery, rather thanrelying on a ventilator,which is an artificial breathing machine

limit the time a person spends underanesthesia

help the person breathe deeply, cough, and walk around right after surgery

use incentive spirometers, which are inexpensive plastic meters, to increaseairflow into the lungs after the surgery

What are the long-term effects of the condition?

The long-term effects are often related to the cause.Atelectasis due to surgery should have no long-term effects. Oncetreated with breathing exercises, the lung should function wellagain. Chronic illnesses, such as emphysemaor cystic fibrosis,may result in atelectasis that never completely resolves. Scar tissuecan form inside of the lung as a result of chronic atelectasis. Thesescarred areas may never function well again.

What are the risks to others?

People with congenital lung diseases, such ascystic fibrosis,may pass a risk of atelectasis on to their children.

What are the treatments for the condition?

Medicines are often used, depending on the problem.For instance, medicines can:

thin respiratory secretions during illnesses such aspneumonia

open the bronchial tubes

stimulate surfactant production

Controlling the pain in people with chest traumas orpeople who have undergone surgery is very important. This enablesthem to do deep breathing exercises, forcing air into their lungs.These exercises open the alveoli and reduce atelectasis.

Some people receive relief from chest physical therapy.This can mechanically remove mucous blocking the airways through clapping,patting, and massaging the chest and back over the lungs. Sometimessuctioning the airway with a small plastic tube may help.

What are the side effects of the treatments?

The side effects of treatment are much less distressingthan the atelectasis. Each medicine will have side effects. Suctioningcan be hard to tolerate, but usually relieves the blockage quite well.

What happens after treatment for the condition?

After treatment, if the cause was short-term as in surgery,the lungs will usually recover fully. But, if the cause wascystic fibrosisor emphysema,the illness may persist and symptoms will recur.

How is the condition monitored?

Monitoring is done with regular physical exams and routinechest x-rays.Pulmonary function testsare done as needed. These tests measure how much air the lungs canhold. They also measure how well the lungs move air in and out,and how well they exchange oxygen and carbon dioxide.