Which of the following findings should make you suspect a history of COPD?

A barrel-shaped chest is a classic physical finding associated with chronic obstructive pulmonary disease (COPD). This characteristic shape occurs due to prolonged hyperinflation of the lungs, which is often seen in patients with emphysema, a common type of COPD. The enlargement of the chest cavity reflects the structural changes that take place in the lungs, leading to the retention of air and reduced ability to expel carbon dioxide.

While other options, such as wheezing, hyper-resonance on percussion, and decreased breath sounds, can also be associated with respiratory conditions, they are not as definitive for a history of COPD as a barrel-shaped chest. Wheezing may indicate bronchospasm but is not specific to COPD, and hyper-resonance on percussion might suggest pneumothorax or other conditions related to air trapping, rather than confirming COPD. Decreased breath sounds could occur due to a variety of factors, including pleural effusion or other lung pathologies, making them less indicative of a history of COPD compared to the distinct physical manifestation of a barrel chest.