Why are postoperative patients at highest risk for atelectasis?

Postoperative patients are at the highest risk for atelectasis due to factors such as reduced lung expansion from anesthesia, pain, and immobility, which can lead to shallow breathing. The effects of anesthesia can also diminish the cough reflex, making it harder to clear secretions and maintain airway patency. Additionally, the presence of surgical incisions, particularly in the abdomen or chest, can further restrict normal respiratory mechanics. These combined factors increase the likelihood of alveolar collapse, resulting in atelectasis.