How does pneumonia impact gas exchange?

Pneumonia significantly impacts gas exchange by inflaming and filling the alveoli with fluid or pus. This accumulation interferes with the normal functioning of the alveoli, which are essential for efficient gas exchange. In a healthy respiratory system, alveoli are air-filled spaces that allow oxygen to enter the blood and carbon dioxide to be expelled.

When pneumonia occurs, the inflammation causes the alveoli to become congested with infectious material, leading to reduced surface area available for gas exchange. The presence of this fluid or pus prevents oxygen from diffusing into the bloodstream effectively and impairs the removal of carbon dioxide from the blood, resulting in decreased oxygen levels (hypoxia) and potentially leading to respiratory distress in patients.

Thus, the impact of pneumonia on gas exchange is primarily due to the obstruction and reduction of functional alveolar space, which is critical for maintaining adequate respiratory function.