After a high-speed collision, a patient presents with difficulty breathing and chest pain. What injury should you suspect?

The presentation of difficulty breathing and chest pain following a high-speed collision strongly suggests a pulmonary contusion as the most likely injury. A pulmonary contusion occurs when the lung tissue is bruised due to trauma, often resulting from blunt force impacts, such as those experienced in high-speed vehicle accidents. This injury can lead to bleeding and inflammation within the lung, causing respiratory compromise, which aligns with the patient's symptoms of difficulty breathing.

In the context of trauma, while other injuries like aortic rupture, sternal fracture, and cardiac tamponade can also occur, they tend to present with different signs and symptoms. Aortic rupture, for instance, is often associated with severe hypotension and shock, not just respiratory distress, while a sternal fracture may cause localized pain but doesn't typically lead to significant breathing difficulties unless there are additional complications like a pneumothorax. Cardiac tamponade can cause breathlessness as well, but it usually arises with other related signs, including jugular vein distention and muffled heart sounds.

Thus, when considering the mechanism of injury and the specific symptoms described, a pulmonary contusion is the most fitting diagnosis in this scenario, highlighting the importance of recognizing the classic presentation of chest trauma in the context of vehicular collisions.