Final Answer:
Pleural effusion typically presents on physical exam with decreased breath sounds and dullness to percussion over the affected area of the chest.
Step-by-step explanation:
Pleural effusion is a condition characterized by an abnormal accumulation of fluid in the pleural space, the space between the lungs and the chest wall. During a physical examination, two key findings suggest the presence of pleural effusion: decreased breath sounds and dullness to percussion.
Firstly, decreased breath sounds are observed as the accumulated fluid hinders the transmission of sounds from the lungs to the chest wall. This occurs because the fluid acts as a barrier, dampening the normal resonance of breath sounds. Clinicians use a stethoscope to listen for these sounds, with decreased breath sounds often localized to the area where the effusion is present.
Secondly, dullness to percussion is detected by tapping the patient's chest with the fingers and listening to the resulting sound. In areas with pleural effusion, the dullness occurs due to the fluid's density, which differs from the resonance of air-filled lung tissue. The transition from resonant to dull percussion notes helps delineate the boundary of the effusion. Combining these physical exam findings aids in the diagnosis of pleural effusion and guides further diagnostic investigations, such as imaging studies (e.g., chest X-ray or ultrasound) and laboratory analyses of the pleural fluid.
In summary, during a physical exam, the clinician assesses for decreased breath sounds and dullness to percussion to identify pleural effusion. These findings prompt additional diagnostic steps to confirm the diagnosis and guide appropriate management.