Table 1.22-1. Differential diagnosis of respiratory diseases based on physical findings

Lesion

Chest movements

Percussion

Vocal fremitusa

Breath sounds

Displacement of the mediastinumb

Infiltrate

Asymmetric, motion impaired on the side of infiltrate

Dull

Increased

Bronchial breathing, crackles

No

Atelectasis

Asymmetric, motion markedly impaired on the side of atelectasis (if large)

Dull

– Reduced (atelectasis caused by airway obstruction)

– Increased (atelectasis caused by airway compression)

– Reduced lung sounds

– Occasional crackles

– Bronchial breathing may be audible

Towards the side of atelectasis in setting of lobar collapse

Fibrosis (bilateral)

Slightly impaired symmetrically

Slightly dull

Slightly reduced

– Reduced lung sounds

– Crackles

No

Pleural effusion

Asymmetric, motion impaired on the side of effusion

Dull

Reduced

Absent breath sounds; in the setting of small pleural effusions pleural friction may be audible

Away from the side of effusion (if large)

Pneumothorax

Asymmetric, motion impaired on the side of pneumothorax

Hyperresonant

Absent

Absent breath sounds

Away from the side of lesion (especially if tension pneumothorax)

Airway obstruction

– Symmetrically increased

– Work of accessory respiratory muscles usually seen

Usually normal

Unchanged or reduced

– Wheezes and rhonchi

– Prolonged expiratory phase

– Normal lung sounds, may be reduced with occasional crackles

No

a Transmission of spoken words while listening with a stethoscope (eg, “blue balloons,” “toy boat”).

b Displacement of the trachea may sometimes be observed on physical examination of the neck.