Why does high FiO2 cause atelectasis?

At FiO2 of 0.3, atelectasis takes hours to develop secondary to absorption; however, this is reduced to approximately 8 minutes with an FiO2 of 1.0. Also, small airways may become completely occluded causing distal gas to be trapped and absorbed leading to airway collapse.

How does oxygen cause atelectasis?

Absorption atelectasis occurs when small pockets of air remain trapped within non-ventilated alveoli. The oxygen and carbon dioxide within these alveoli are gradually reabsorbed into the pulmonary circulation, which causes the alveoli to collapse, and subsequently, collapse of a portion of the lung.

How does atelectasis affect oxygen saturation?

If atelectasis affects only a small area of the lungs, you may not have any symptoms. But if it affects larger areas, the lungs cannot fill with enough air, and the oxygen level in your blood may go down.

How does nitrogen prevent atelectasis?

If absorption atelectasis plays a major role in the genesis of perioperative pulmonary collapse, then it should be possible to reduce the amount of collapse by modifying the inspired gas composition by including a less soluble gas such as nitrogen. the transmural pressure distending the alveolus is reduced.

What are the causes of atelectasis?

Possible causes of nonobstructive atelectasis include:

  • Injury. Chest trauma — from a fall or car accident, for example — can cause you to avoid taking deep breaths (due to the pain), which can result in compression of your lungs.
  • Pleural effusion.
  • Pneumonia.
  • Pneumothorax.
  • Scarring of lung tissue.
  • Tumor.

How is atelectasis absorption treated?


  1. Performing deep-breathing exercises (incentive spirometry) and using a device to assist with deep coughing may help remove secretions and increase lung volume.
  2. Positioning your body so that your head is lower than your chest (postural drainage).
  3. Tapping on your chest over the collapsed area to loosen mucus.

Can I recover from atelectasis?

Mild atelectasis may go away without treatment. Sometimes, medications are used to loosen and thin mucus. If the condition is due to a blockage, surgery or other treatments may be needed.

Which type of atelectasis is the most common?

Obstructive atelectasis is the most common type and results from reabsorption of gas from the alveoli when communication between the alveoli and the trachea is obstructed. The obstruction can occur at the level of the larger or smaller bronchus.

How is FiO2 used to reduce atelectasis?

Using lower FIO2 (30%) during induction can effectively decrease the amount of atelectasis, however this is associated with a lower safety margin is patients who may be difficult to intubate.

How does atelectasis affect the function of the blood?

The blood delivers the oxygen to organs and tissues throughout your body. When air sacs become deflated because of atelectasis, they cannot inflate properly or take in enough air and oxygen. If enough of the lung is affected, your blood may not receive enough oxygen, which can cause health problems. Atelectasis often develops after surgery.

When does atelectasis appear after anesthesia induction?

The atelectasis appears within minutes after anesthesia induction in nearly 90% of patients. The degree of atelectasis is larger with obese patients and when a higher fraction of inspired oxygen (FI02) is used.

Who is suffering from obstructive atelectasis with high flow nasal?

We present here the case of a 45-year-old patient with a history of severe restrictive lung disease due to a congenital spinal muscular atrophy, who developed acute respiratory failure due to complete atelectasis of the left lung associated with community-acquired pneumonia.