Adventitious Breath Sounds Quiz

Inspiratory Sound

• Inspiratory sound is longer than expiratory sound
• Inspiration continues without pause through expiration, fading away about one-third of the way through expiration
• Heard over most of the lung fields

Adventitious or Added Breath Sounds

• Crackles (Rales or crepitation): • Associated with pulmonary edema, early CHF, and pneumonia • Discontinuous, intermittent, non-musical, brief sounds • Heard more commonly with inspiration • Classified as fine or coarse • Caused by air moving through secretions and collapsed alveoli

• Wheeze: • Associated with asthma and COPD • Produced when air flows through narrowed airways • Continuous, high-pitched, musical sound, longer than crackles • Heard more with expiration, can be heard on inspiration

• Rhonchi: • Similar to wheezes, but clear upon coughing • Low-pitched, snoring quality, continuous, musical sounds • Implies obstruction of larger airways by secretions • Associated with acute bronchitis

• Stridor: • Intense inspiratory musical wheeze • Heard loudest over extra-thoracic airways • Can be heard without a stethoscope • Suggests obstructed upper airway • Medical emergency requiring immediate attention

Airway Resistance and Turbulent Flow

• Turbulence increases airway resistance
• Occurs in larger airways where velocity is high and at branch points
• Disorganizes air flow and increases the driving pressure and its resistance
• Bronchoconstriction reduces airway diameter and increases velocity of flow, creating turbulence and generating wheezing in bronchial asthma

Pulmonary Function Tests

• A group of tests that measure how well the lungs take in and release air and move gases such as O2 from the atmosphere into the body's circulation
• Spirometer is an instrument used to evaluate respiratory function
• Can distinguish between: • Obstructive pulmonary disease – ↑ airway resistance • Restrictive pulmonary disease – ↓ in total lung capacity from structural/functional lung changes