Atelectasis is a complete or partial collapse of a lung or lobe of a lung which develops when the tiny air sacs (alveoli) within the lung become deflated. It is one of the most common breathing  complications after surgery. Atelectasis is also a possible complication of other respiratory problems, including cystic fibrosis, inhaled foreign objects, lung tumors, fluid in the lung, severe asthma and chest injuries.

Atelectasis can be serious because it reduces the amount of oxygen available to the body. The amount of lung tissue involved in atelectasis is variable, depending on the cause. Treatment depends on the cause and severity of the collapse. The signs and symptoms of atelectasis also vary.

Symptoms

There may be no obvious symptoms of atelectasis. However, some of them are:

  • Rapid, shallow breathing,
  • Difficulty breathing (dyspnea),
  • Coughing,
  • Low-grade fever.

Causes

Atelectasis may be caused by a blocked airway (obstructive) or by pressure from outside the lung (nonobstructive).

Almost all patients who undergo surgery have some atelectasis from anesthesia, which changes the dynamics of airflow in the lungs, the absorption of gases and pressures, all of which combine to cause some degree of collapse of the tiny air sacs (alveoli) in the lungs. It is particularly prominent after heart bypass surgery.

Obstructive atelectasis may be caused by a blockage in the air passages (bronchial tubes) like a mucus plug, foreign body, narrowing of major airways from disease, tumor in a major airway or blood clot.

Possible causes of nonobstructive atelectasis include: injury, pleural effusion, pneumonia, pneumothorax, scarring of lung tissue and tumor.

Risk factors

Factors that increase the risk of atelectasis include:

  • Any condition that interferes with spontaneous coughing, yawning and sighing,
  • Premature birth, if the lungs aren't fully developed,
  • Impaired swallowing function, particularly in older adults — aspirating secretions into the lungs is a major source of infections,
  • Lung disease, such as asthma, bronchiectasis or cystic fibrosis,
  • Confinement to bed, with infrequent change of position,
  • Abdominal or chest surgery,
  • Recent general anesthesia,
  • Shallow breathing
  • Respiratory muscle weakness,
  • Age,
  • Obesity.

Complications

The following complications may result from atelectasis:

  • Low blood oxygen (hypoxemia),
  • Lung scarring,
  • Pneumonia,
  • Respiratory failure.

Prevention

To decrease the risks of atelectasis :

  • Be careful with small objects and prevent providing a possibility for the children to swallow them,
  • Stop smoking,
  • Do deep-breathing exercises,
  • If you need to stay in bed, reposition yourself and make attempts to move and walk.