Atelectasis

https://www.verywellhealth.com/understanding-atelectasis-2248927
Atelectasis is a medical term used to describe the complete or partial collapse of a lung. It is
sometimes referred to as a "collapsed lung," although the term can also be applied to a
condition called pneumothorax.
When atelectasis occurs, fresh air is unable to reach the tiny structures of lungs, called the
alveoli, where oxygen and carbon dioxide are exchanged. This results in decreased levels of
oxygen being delivered to the organs and tissues of the body (hypoxia).
Atelectasis may be acute, occurring suddenly over the matter of minutes, or chronic, developing
over a period of days to weeks. There are four main causes of atelectasis, which in turn may be
caused by a number of different medical conditions, ranging from lung cancer, to an enlarged
heart.
Atelectasis often has few symptoms if it develops slowly or involves only a small portion of the
lung. Conversely, if the condition develops rapidly or affects a larger portion of shock, symptoms
may be dramatic and even lead to shock. Atelectasis typically occurs unilaterally, meaning in
either one lung or the other.
Common symptoms include:
Shortness of breath (dyspnea)

 Wheezing
 Rapid shallow breathing
 A persistent, hacking cough
 A sharp chest pain that worsens with a deep breath, typically on one side of the chest
As the condition progresses, the symptoms can become more profound as oxygen saturation
levels in the blood begin to decrease. This can lead to a sudden, severe drop in blood pressure,
rapid heart rate (tachycardia), and shock.
Seek emergency care if the breathing difficulty is accompanied by severe chest pain, rapid heart
rate, rapid breathing, clammy skin, lightheadedness, or cyanosis (a bluish color of the skin,
particularly the lips, chest, and tongue)
There are four primary causes of atelectasis: hypoventilation, airway obstruction, airway
compression, and adhesions. Understanding these mechanisms makes it a little easier to
understand some of the common medical conditions that may result in this condition.
Hypoventilation, or breathing at an abnormally slow rate, is common during surgery, especially
with general anesthesia, or when a person is placed on a respirator. The very act of shallow
breathing prevents air from getting to the alveoli, causing the air sacs to deflate and collapse.
Hypoventilation is the most common cause of atelectasis, especially after chest surgery.
Airway obstruction may be caused when something blocks a passage either inside the lung (like
a mucus plug or a foreign object) or outside of the lungs (like a tumor which presses on the
airway and causes obstruction). Bronchioloalveolar carcinoma is one type of cancer (now
renamed as a subtype of lung adenocarcinoma) known to cause tumors in the alveoli and allied
passages.
Compression of the airways is often caused by the buildup of fluid in the space surrounding the
lungs (pleural effusion). It may also be the result of an enlarged heart, an aneurysm, a tumor,
enlarged lymph nodes, or accumulation of fluids in the abdominal cavity (ascites).
Adhesions are an abnormal condition where tissues begin to stick together. Normally, internal
tissues and organs have slippery surfaces, so they can shift easily as the body moves.
Other factors contributing to atelectasis include obesity, smoking, prolonged bed rest/immobility,
rib fractures (which can result in shallower breathing), narcotics or sedatives (which can slow
respiration), and respiratory distress syndrome (RDS) in newborns.
Diagnosis
If your doctor suspects you have atelectasis, he or she will perform a physical exam by tapping
on (percussing) the chest to listen for tell-tale sounds. If there is a partial or complete lung
collapse, breathing sounds may be quiet or noticeably absent.
Following this, the doctor will order a number of investigations which may include:

 Chest X-ray, which may reveal that the trachea and heart have shifted position
 Computed tomography (CT scan) to look for visual evidence of obstruction
 Magnetic resonance imaging (MRI), using magnetic waves to produce images
 Bronchoscopy, a flexible scope inserted into the windpipe to view the lungs that may
reveal a tumor or foreign body in an airway that has led to the collapse
 Blood gases (oximetry) to evaluate the level of oxygen deprivation
 Positron-emission tomography (PET scan), which can spot hyperactive cell metabolism
as can occur with cancer
Treatment
Treatment of atelectasis depends on the underlying cause, with the aim of re-expanding the
lung to its normal size. The approaches can vary. If a tumor is the cause of the collapse, surgery
may be involved.
With small degrees of atelectasis that are found while an infection or tumor is being actively
treated, physicians may simply observe the area of atelectasis to see if it resolves with
appropriate treatment of the underlying problem.8 In this case, breathing exercises, chest
percussion, or postural drainage may help accelerate improvement and relieve some of the
symptoms.
For pleural effusion, drainage of the pleural cavity may be required.5 For internal obstructions,
bronchoscopy may be used to remove a foreign object, while bronchodilation medications may
assist with the opening of airway passages. In most cases, a combination of therapeutic
approaches will be needed.
When symptoms are pronounced, positive end-expiratory pressure (PEEP) may be used.9 This
is a treatment in which a mixture of oxygen is given via endotracheal tube, preventing the lungs
from collapsing completely during exhalation. If symptoms are severe, intubation and ventilation
(placing a person on a respirator) may be needed until the underlying condition is fully under
control.
When atelectasis is chronic, it can often be difficult to get the lungs to re-expand. Removal of
the damaged portion of the lung (via a lobectomy or segmental resection) may be indicated.

Complications
Complications may result when bacteria become trapped in the area of the collapse. This can
lead to the development of an infection, including pneumonia and sepsis. Bronchiectasis, an
abnormal widening of the airways which results in a pooling of fluid the lungs, can also
sometimes occur. When a large portion of the lungs is affected by these things, respiratory
failure may result.1
Prevention

 Chest surgery remains the predominant cause of atelectasis. To prevent it from

occurring after a surgical procedure, doctors will typically advise you to stop smoking
first and foremost.7
 After surgery, there are four things you should do ensure your lungs remain fully
inflated:1
 Use an incentive spirometer, a simple medical device to keep your lungs healthy. It's the
most used device that prevents atelectasis.
 Perform deep breathing exercises, focusing on long inhales and controlled exhales. Pain
medication may also be prescribed if breathing is especially uncomfortable.
 Make an effort to cough to clear any mucus or sputum from the lungs.
 Change your position, sitting up or moving around as much as your doctor allows.