Which respiratory condition is characterized by a "barrel chest"?

A "barrel chest" is a physical condition characterized by an increased anterior-posterior diameter of the thorax, often associated with chronic obstructive pulmonary disease (COPD), particularly emphysema. In emphysema, the air sacs in the lungs are damaged and lose their elasticity, leading to trapped air that causes the lungs to overinflate. This overinflation can make the chest appear rounded or barrel-shaped.

The morphology of the chest in emphysema is due to the need for the individual to use accessory muscles for breathing, as the ability to expel air effectively is compromised. This adaptation results in a more pronounced chest shape over time. The presence of a barrel chest is a typical clinical sign that respiratory therapists and other healthcare providers look for when assessing patients with emphysema.

Other respiratory conditions, like pneumonia, asthma, and chronic bronchitis, do not typically cause this specific change in chest shape. For example, pneumonia can result in decreased lung volumes and isn't associated with a barrel-shaped thorax, while asthma is characterized by airway obstruction and may lead to an acute change in chest shape but not a permanent barrel chest. Chronic bronchitis can lead to some changes in lung structure, but it primarily causes hypersecretion