Question

Why are most cases of aspiration pneumonia in the middle and lower lobe of the right lung? Consider the anatomic pathway.

Answer 1

Aspiration pneumonia is a condition caused by entering of oral or gastric contents such as food, vomit or liquid in the bronchial tubes or lungs. Oral and gastric cavity usually contains many kind of bacteria in it which are aspirated in the lungs and grow there to become pneumonia. The site of aspiration pneumonia often depends on gravity, according to patient position. As aspiration pneumonia is most common in unconscious or sub conscious state that is patient is leaning or lying down. Generally, the middle lobe and lower lobe of right lung are the most commonly affected locations of such pneumonia. It is due to the fact that the bronchus connecting oral cavity to right lung has larger capacity and more upright (vertical) alignment in comparison to of the left main stem bronchus. Although in patients where aspiration occurs while standing can have two-sided lower lung lobe infiltration of gastric material causing a bilateral pneumonia.