Expansion
Resonant, dull, stony dull and hyperresonant
Expansion
| Note | Meaning | Causes |
|---|---|---|
| Resonant | Normal aerated lung | |
| Hyperresonant | Excess air | Pneumothorax, severe emphysema, large bulla |
| Dull | Reduced air, increased tissue | Consolidation, collapse, fibrosis, mass, raised hemidiaphragm |
| Stony dull | Fluid | Pleural effusion, haemothorax, empyema |
Technique: percuss the clavicle directly, then the chest wall symmetrically, comparing side with side at each level, front, sides and back, including the axillae. Do not percuss over the scapulae.
Combining percussion with the other signs is what makes the examination diagnostic:
| Pathology | Expansion | Percussion | Breath sounds | Vocal resonance |
|---|---|---|---|---|
| Consolidation | Reduced | Dull | Bronchial | Increased |
| Effusion | Reduced | Stony dull | Reduced or absent | Reduced |
| Pneumothorax | Reduced | Hyperresonant | Reduced or absent | Reduced |
| Collapse | Reduced | Dull | Reduced | Reduced |
| Fibrosis | Reduced | Normal or dull | Bronchial, fine crackles | Increased |
The trachea then distinguishes the causes of a whole hemithorax problem: pushed away by a tension pneumothorax or large effusion, pulled towards by collapse or fibrosis.
Cardiac dullness is lost in emphysema and hyperinflation, and liver dullness descends.