Barrel-shaped chest with hyperinflated lungs is most characteristic of which condition?

• A. Chronic bronchitis
• B. Emphysema
• C. Pulmonary edema
• D. Atelectasis

Answer: (B)

Barrel-sized chest with hyperinflated lungs comes from air trapping due to loss of elastic recoil in alveolar walls, a hallmark of emphysema. In emphysema, destruction of the alveolar septa and reduced elastic tissue allow air to remain in the lungs at the end of expiration, expanding the lungs and flattening the diaphragms over time. This increased air trapping raises the anteroposterior diameter of the chest, giving a barrel-shaped appearance.

Chronic bronchitis involves thickened airways with mucus hypersecretion and mucus plugging, which can obstruct air flow but is not defined by the same degree of alveolar destruction and severe hyperinflation that produces a barrel chest. Pulmonary edema reflects fluid overload in the lungs, causing dyspnea and crackles rather than a chronically inflated, barrel-shaped chest. Atelectasis is lung collapse leading to decreased volume, not hyperinflation or barrel chest.

So the combination of a barrel-shaped chest and hyperinflation most strongly points to emphysema due to its fundamental change—air trapping from loss of elastic recoil.