The Lung Exam

LSU Physician Champion - Dr. Carol Mason

Normal Lung Sounds

Normal Lung Sounds originate from the sound of air moving normally in the bronchi and alveoli the number of tissue interfaces between the airways and the stethoscope affects the intensity and quality of the breath sounds Types:

#1 Vesicular breath sounds – from air entry into the alveoli - are an inspiratory sound - best heard at the posterior bases of the lungs  

#2 Bronchial breath sounds - from air turbulence in the larger cartilaginous bronchi - harsh and loud, but markedly diminish after transmission through the alveoli - best heard over the trachea

#3 Bronchovesicular breath sounds - a combination of #1 and #2 - heard where a narrow area of the lung (with alveoli) overlie a bronchus - best heard over the right infraclavicular area in close proximity to the sternum

Abnormal Breath Sounds - Auscultation

1. Crackles (formerly rales, now an obsolete term) - result from air and fluid in the alveoli - primarily an inspiratory sound, resulting from opening of the alveoli (containing fluid and air) in inspiration - characterized as fine (velcro or crepitant), coarse, wet, or musical - are obliterated when fluid completely fills the alveoli  

2. Rhonchi - harsh loud sounds that may occur in inspiration and expiration - arise from air turbulence in bronchi due to mucus, secretions, partially obstructing foreign body - may clear after coughing  

3. Wheezes - result from narrowing of the small airways - high-pitched and whistling sounds - prototypical of asthma - inspiratory phase is prolonged - may be inspiratory and expiratory - usually diffuse, but may be focal with a partially obstructed airway (cancer, foreign body)

4. Bronchial breath sounds - occur over abnormal areas of the lung when complete consolidation (i.e., with lobar pneumonia) - occur over areas of the lung where vesicular breath sounds would normally be expected - produced by transmission of bronchial breath sounds through the consolidated lung (airless lung, that no longer baffles the bronchial sounds)

5. Bronchophony - sound of the spoken voice over a bronchus - when occurs elsewhere (other than over large bronchi or trachea), implies consolidation of the lung

6. Whispered pectoriloquy - reproduction of a bronchial whisper in an unexpected area that normally would not transmit the sounds of whisper (i.e., not over a bronchus) - also implies consolidated lung

7. Egophany - occurs when lung is consolidated and lower pitched sounds are damped - in area of consolidation, have the patient say “e”, which will sound like “a” , as only the higher pitched sounds are transmitted - listen side-to-side to compare to a normal area of lung as well, to assure yourself the patient is really saying “e”

8. Diminished breath sounds, usually due to COPD - occurs in the setting of moderate to severe obstructive lung disease (without pleural effusion or other secondary process) - best heard over the posterior lung fields - must be able to recognize normal vesicular breath sounds initially, which makes reduced breath sounds more apparent - one of the best physical exam predictors that the patient has COPD - hyperresonance (percussion) is also an exam predictor of emphysema or COPD  

The following is an audio site for both normal and abnormal breath sound examples:   Normal and Abnormal Breath Sounds