Certified Respiratory Therapist Practice Exam

What does reduced chest expansion and hyperresonance on the left hemithorax indicate in an acutely dyspneic patient?

1. Left-sided pneumonia

2. Left-sided pneumothorax

3. Left-sided pleural effusion

4. Left lower lobe consolidation

The correct answer is: Left-sided pneumothorax

Reduced chest expansion and hyperresonance on the left hemithorax strongly suggest a left-sided pneumothorax. In a pneumothorax, air escapes into the pleural space, leading to an increase in intrapleural pressure. This accumulation of air can result in diminished lung expansion on the affected side, which is reflected in reduced chest expansion during respiratory movements. Hyperresonance occurs because the presence of extra air in the pleural cavity creates an abnormal resonance when the chest is percussed. In normal conditions, lungs filled with fluid or solid material produce dull sounds, whereas air-filled spaces yield a more resonant sound. The combination of these clinical findings—reduced chest expansion and the hyperresonant percussion note—forms a clinical picture that is characteristic of a pneumothorax, particularly in the context of acute dyspnea. Understanding the pathological changes associated with a pneumothorax helps in differentiating it from other conditions like pneumonia, pleural effusion, or consolidation, each of which would present with different physical examination findings. For instance, pneumonia would typically show dullness on percussion due to fluid or consolidation in the lung tissue, while pleural effusion would present with decreased tactile frem