LECTURE 11 (Lung auscultation) Flashcards
What happens when we breathe?
Air travels down the throat into the TRACHEA -> Trachea divides into BRONCHIAL TUBES -> Bronchial tubes go into each lung and branch into BRONCHIOLES which each have an ALVEOLI
What is the anatomy of the lungs?
- Respiratory tract = extends from mouth/nose to alveoli
- Upper airway = filters airborne particles, humidifies and warms inspired gases
- Lower airway = gas exchange
What should be done to prepare for the Respiratory exam?
- Quiet space
- Proper positioning
- Warm hands + stethoscope
- Exam done on bare skin
Who discovered the concept of auscultation?
Hippocrates
What is Auscultation?
The process of listening to the sounds of air passing through the tracheobronchial tree and alveolar spaces
Why is Auscultation necessary?
Alterations in airflow and ventilation effort result in distinctive sounds within the chest that may indicate pulmonary disease or dysfunction
What are the properties of Auscultation?
- Cheap, non-invasive & easy to perform
- Helps in differentiating normal respiratory sounds from abnormal ones
What are the Left lateral landmark lines?
1) Posterior axillary line
2) Left upper lobe
3) Left lower lobe
4) Midaxillary line
5) Anterior axillary line
What are the three characteristics of lung sounds?
- Pitch = perceptual quality of sound that depends on frequency of the sound wave
- Intensity = subjective assessment to determine whether a sound is loud or soft
- Quality = differentiates two sounds with the same pitch and loudness
Describe normal lung sounds
- Created by turbulent air flow
- Inspiration [air moves to smaller airways hitting walls -> more turbulence -> increased sound]
- Expiration [air moves toward larger airways -> less turbulence -> decreased sound]
- Loudest during inspiration & softest during expiration
What are the three normal heart sounds?
- Vesicular
[low pitch, Inspiratory > Expiratory & heard over most of normal lung] - Broncho-vesicular
[medium pitch & heard over mainstream bronchi] - Bronchial (tracheal)
[high pitch & normally heard over trachea]
Describe Broncho-vesicular lung sounds
- Medium pitch & intensity
- Inspiratory = Expiratory sound duration
- Heard best 1st and 2nd ICS anteriorly and between scapula posteriorly
- If heard anywhere else -> not normal
Describe Tracheal lung sounds
- Very loud & high pitched
- Inspiratory = Expiratory sound duration
- Heard over trachea
Describe Bronchial lung sounds
- Loud & high pitched sound
- Expiratory sounds > Inspiratory sounds
- Heard over manubrium of sternum
- If heard anywhere else -> not normal
What are Adventitious sounds?
Abnormal lung sounds caused by moving air colliding with secretions in the tracheobronchial passageways or by “popping open” of previously deflated airways
What are the major types of abnormal lung sounds?
- Crackles (rales)
- Rhonchi
- Wheezes
- Stridor
- Pleural rub
Describe Crackles (Rales)
- Discrete, non-musical, non-continuous sound produced by moisture in the lung tissues
- Can be fine in quality or coarse
- Sound like cellophane being crumbled
Describe Rhonchi
- Continuous sounds produced by air being forced through narrow passages, narrowed by secretions and/or constriction of the air passage
- Similar to wheezes
- Low pitched, snoring quality, continuous sounds
- POSSIBLE CAUSE: ACUTE BRONCHITIS
Describe Wheezes
- Continuous sounds produced as air is forced through narrow passages
- Occur in inspiration or expiration
- May change character after coughing
- POSSIBLE CAUSE: ASTHMA, COPD, SMOKING
Describe Stridor
- Loud sound of constant pitch, most prominent during inspiration
- Can be heard very well at a distance due to its loud intensity (No stethoscope needed)
- Suggests obstructed trachea or larynx
- MEDICAL EMERGENCY!
- POSSIBLE CAUSE: INHALED FOREIGN BODY
Describe Pleural Rub
- Non-musical sound, usually longer and lower pitch than lung crackles
- Discontinuous/continuous brushing sounds
- Occurs during inspiration/expiration
- Sounds like creaking of old leather
- CAUSE: Coarsened surface of normal pleura due to FIBRIN DEPOSITS, THICKENED/INFLAMED OR WITH NEOPLASTIC CELLS
What is Bronchophony?
Clear, distinct, intelligible voice sound heard over dense, airless lung tissue
What is Egophony?
Increased resonance of voice sounds heard when auscultating the lungs
What is Whispered pectoriloquy?
Clear, distinct, intelligible whispered voice sound heard over airless, consolidated or atelectatic lung tissue
What is involved in Pulmonary assessment?
- Inspection
- Palpation
- Percussion
- Auscultation
