Before you begin, there are certain things that you should keep in mind: a) It is important that you try to create a quiet environment as much as possible. b) The patient should be in the proper position for auscultation. c) Your stethoscope should be touching the patient’s bare skin whenever possible or you may hear rubbing of the patient’s clothes against the stethoscope and misinterpret them as abnormal sounds.
d) Always ensure patient comfort. Be considerate and warm the diaphragm of your stethoscope with your hand before auscultation.
Remember - Don't examine thru clothing or "snake" stethoscope down shirts/gowns
Vesicular Breath Sound The vesicular breath sound is the major normal breath sound and is heard over most of the lungs. They sound soft and low-pitched. The inspiratory sounds are longer than the expiratory sounds. Vesicular breath sounds may be harsher and slightly longer if there is rapid deep ventilation (eg post-exercise) or in children who have thinner chest walls. As well, vesicular breath sounds may be softer if the patient is frail, elderly, obese, or very muscular.
The vesicular breath sound is the major normal breath sound and is heard over most of the lungs. The inspiratory sounds are longer than the expiratory sounds. Inspiration Expiration heard only during the first third of the expiration phase
Vesicular breathing may be louder or softer for both physiological and pathological reasons. 1.Vesicular breath sounds may be harsher and slightly longer if there is rapid deep ventilation or in children (“ puerile respiration” ). 2.Vesicular breath sounds may be softer if the patient is frail, elderly, obese, or very muscular. ! Physiological changes in vesicular respiration always involve both parts of the chest, and respiratory sounds are equally intensified at the symmetrical points of the chest.
Alterations in vesicular respiration in pathology depend on: ― the amount of intact alveoli; ― the properties of their walls; ― the amount of air contained in them; ― the length and strength of the expiration and inspiration phases; ― the conditions of sound conduction from the vibrating elastic elements of the pulmonary tissue to the surface of the chest.
Pathologically decreased vesicular respiration can be: ~ due to a significantly diminished number of the alveoli; ~ due to inflammation and swelling of the alveoli walls in a part of the lung; ~ decreased also in insufficient delivery of air to the alveoli through the air ways; ~ due to obstructed conduction of sound waves from the source of vibration (alveolar walls) to the chest surface.
1. Abnormally increased vesicular breathing depends on obstruction to the air passage through small bronchi or their contracted lumen (increased expiration). 2. Harsh vesicular breathing occurs in marked and nonuniform narrowing of the lumen in small bronchi and bronchioles due to inflammatory oedema of their mucosa (the inspiration and expiration phases are intensified).
3. Interrupted or cogwheel vesicular respiration is characterized by short jerky inspiration efforts interrupted by short pauses between them; the expiration is usually normal (occurs in non-uniform contraction of the respiratory muscles, when a patient is auscultated in a cold room, or when he has nervous trembling, or diseases of the respiratory muscles, Interrupted breathing over a limited part of the lung indicates pathology in fine bronchi (their tuberculous infiltration)
Bronchial Breath Sound Respiratory sounds known as bronchial or tubular breathing arise in the larynx and the trachea as air passes through the vocal slit. As air is inhaled, it passes through the vocal slit to enter wider trachea where it is set in vortex-type motion. Sound waves thus generated propagate along the air column throughout the entire bronchial tree. Sounds generated by the vibration of these waves are harsh. During expiration, air also passes through the vocal slit to enter a wider spase of the larynx where it is set in a vortex motion. But since the vocal slit is narrower during expiration, the respiratory sound becomes longer, harsher and longer. This type of breathing is called laryngotracheal
Respiratory sounds known as bronchial or tubular breathing arise in the larynx and the trachea as air passes through the vocal slit. Еxpiration Inspiration
Bronchial breathing can be heard instead of vesicular (or in addition to the vesicular breathing) over the chest in pulmonary pathology. This breathing is called pathological bronchial respiration.
If these sounds are heard anywhere other than over the manubrium, it is usually an indication that an area of consolidation exists (i.e. space that usually contains air now contains fluid or solid lung tissue). Bronchial breath sounds.
Amphoric respiration arises in the presence of a smooth-wall cavity( non less than 5-6 cm in diameter) communicated with a large bronchus Metallic respiration differs from both bronchial and amphoric. It is loud and high, and resembles the sound produced when a piece of metal is struck. Metallic respiration is heard in open pneumothorax when the air of if pleural cavity communicates with the external air. Stenotic respiration is heard in cases with narrowed trachea or a large bronchus (due to a tumor); Bronchovesicular or mixed respiration is heard in lobular pneumonia or infiltrative tuberculosis, and also in pneumosclerosis, with foci of consolidated tissue being seated deeply in the pulmonary tissue and far from one another.
Bronchovesicular Breath Sound These are breath sounds of intermediate intensity and pitch. The inspiratory and expiratory sounds are equal in length. They are best heard in the 1st and 2nd ICS (anterior chest) and between the scapulae (posterior chest) - ie over the mainstem bronchi. As with bronchial sounds, when these are heard anywhere other than over the mainstem bronchi, they usually indicate an area of consolidation.
Tracheal Breath Sound Tracheal breath sounds are very loud and relatively high-pitched. The inspiratory and expiratory sounds are more or less equal in length. They can be heard over the trachea which is not routinely auscultated.
Normal Breath Sounds Feature TrachealBronchialBroncho vesicular Vesicular Location TracheaManubri um Mainstem bronchi Peripheral lung Quality Loud, harsh, hollow Loud, less harsh, hollow Soft Softer Pitch HighestHigher High Low Duration /"\ -""\ ^\ /"
Adventitious sounds are rales, crepitation, and pleural friction.
Rales arise in pathology of the trachea, bronchi, or if a cavern is formed in the affected lung. Rales are classified as dry (rhonchi) and moist rales.
Dry rales can be due to (1) spasms of smooth muscles of the bronchi during fits of bronchial asthma; (2) swelling of the bronchial mucosa during its inflammation; (3) accumulation of viscous sputum in the bronchi which adheres to the wall of the bronchus and narrows its lumen; (4) formation of fibrous tissue in the walls of separate bronchi and in the pulmonary tissue with subsequent alteration of their architectonics (bronchiectasis, pneumosclerosis); (5) vibration of viscous sputum in the lumen of large and medium size bronchi during inspiration and expiration: being viscous, the sputum can be drawn (by the air stream) into threads which adhere to the opposite walls of the bronchi and vibrate like strings.
Dry rales are heard during inspiration and expiration and vary greatly in their loudness, tone and pitch. According to the quality and pitch of the sounds produced, dry rales are divided into: sibilant (high-pitched and whistling sounds are produced when the lumen of the small bronchi is narrowed) sonorous rales (low-pitched and sonoring rales are generated in stenosis of medium calibre and large calibre bronchi or when viscous sputum is accumulated in their lumen).
Moist rales are generated because of accumulation of liquid secretion (sputum, oedematous fluid, blood) in the bronchi through which air passes. Air bubbles pass through the liquid secretion of the bronchial lumen and collapse to produce the specific cracking sound. Moist rales are heard during both the inspiration and expiration, but since the air velocity is higher during inspiration, moist rales will be better heard at this respiratory phase.
Depending on the calibre of bronchi where rales are generated, moist rales are classified as fine, medium and coarse bubbling rales. Fine bubbling rales are generated in fine bronchi and are percepted by the ear as short multiple sounds; Medium bubbling rales are produced in bronchi of a medium size; Coarse bubbling rales in large calibre bronchi, in large bronchiectases, and in pulmonary cavities (abscess, cavern) containing liquid secretions and communicating with the large bronchus.
Depending on the character of the pathology in the lungs, moist rales are subdivided into: ~ consonating or crackling, ~ non-consonating or bubbling rales. Consonating moist rales are heard in the presence of liquid secretions in the bronchi surrounded by airless (consolidated) pulmonary tissue or in lung cavities with smooth walls surrounded by consolidated pulmonary tissue. The cavity itself acts as a resonator to intensify moist rales.
Non-consonating rales are heard in inflammation of bronchial mucosa (bronchitis) or acute oedema of the lung due to the failure of the left chambers of the heart. The sounds produced by collapsing air bubbles in the bronchi are dampened by the "air cushion" of the lungs as they are conducted to the chest surface.
Crepitation originates in the alveoli. Crepitation is a slight crackling sound that can be imitated by rubbing a lock of hair. The main condition for generation of crepitation is accumulation of a small amount of liquid secretion in the alveoli. During expiration, the alveoli stick together, while during inspiration the alveolar walls are separated with difficulty and only at the end of the inspiratoryn movement. Crepitation is therefore only heard during the heighi of inspiration. In other words, crepitation is the sound produced by many alveoli during their simultaneous reinflation.
Pleural friction sound. Pleural friction sound are heard during both inspiration and expiration. The sounds are differentiated by intensity, or loudness, length, and site over which they are heard.
Pleural friction sounds can be differentiated from fine bubbling rales and crepitation by the following signs: (1) the character of rales is altered or rales can disappear for a short time after coughing, while pleural frictionsounds does not change in these conditions; (2) when a stethoscope is pressed tighter against the chest, the pleural friction sound is intensified, while rales do not change; (3) crepitation is only heard at the height of inspiration, while pleural friction sound is heard during both inspiration and expiration; (4) if a patient moves his diaphragm in and out while his mouth and nose are closed, the sound produced by the friction of the pleura due to the movement of the diaphragm can be heard, while rales and crepitation cannot because there is no air movement in the bronchi.
Common errors of auscultation: _ Auscultating one entire lung, and then moving to the other lung __Auscultating over a patient’s gown or article of clothing __Beginning auscultation inferiorly at the lower lung fields __Moving your stethoscope before each exhalation is complete __Examiner does not make the room quiet enough to hear breath sounds.