What is the most common cause of hypoxemia in a surgical patient?

Microatelectasis is often recognized as the most common cause of hypoxemia in surgical patients due to its frequent occurrence postoperatively. After surgery, particularly during the early phases of recovery, patients may not take deep breaths due to pain or sedation, which can lead to partial collapse of the alveoli, known as atelectasis. This condition reduces surface area for gas exchange and can significantly impair oxygenation, resulting in hypoxemia.

Additionally, the likelihood of microatelectasis is increased in patients who undergo general anesthesia, as the controlled ventilation may not fully expand the lungs or recruit all alveoli effectively, especially if adequate incentive spirometry or other requisites for lung expansion are not utilized. Subsequently, this makes monitoring and addressing microatelectasis crucial in the postoperative setting to maintain optimal oxygenation and prevent complications associated with hypoxemia.