General anesthesia is a common cause of atelectasis. It changes your regular pattern of breathing and affects the exchange of lung gases, which can cause the air sacs (alveoli) to deflate. Nearly everyone who has major surgery develops some amount of atelectasis.

Why are post op patients at risk for atelectasis?

The main risk factors for developing atelectasis in the surgical patient include: Age. Smoking. Use of general anaesthesia.

How does Anaesthesia cause atelectasis?

Causes of atelectasis formation during general anaesthesia

Compression atelectasis occurs when the transmural pressure distending the alveolus is reduced. Absorption atelectasis occurs when less gas enters the alveolus than is removed by uptake by the blood.