Auscultation.pptx
- 1. AUSCULTATION
- 2. Auscultation is a simple, non-invasive procedure that involves the use of a stethoscope to listen to the sounds produced by the body. A stethoscope amplifies the sounds within the lungs so that we can hear and have an idea of what’s going on with the patient’s condition. When performing lung auscultation, the bell or diaphragm of the stethoscope is placed on the patient’s chest and/or back. Both sides can be compared with one another and the sounds of each lung should be compared as well.
- 3. A stethoscope is a closed acoustic system where air serves as a transmitting medium for sounds.Therefore, if the tube is clogged, or communicates with ambient air, auscultation becomes impossible.The skin against which the bell of the stethoscope is pressed acts as a membrane whose acoustic properties change under pressure: if the pressure on the skin increases higher frequencies are better transmitted, and vice versa. Excess pressure on the bell damps vibration of the underlying tissues. A large bell better transmits lower frequencies.
- 4. Auscultation techniques -silence in the room and the absence of any extraneous sounds -the ambient temperature should provide comfort for the undressed patient -patient is either sits or stands upright -the skin to which the bell of the phonendoscope is pressed should be hairless -bell should be pressed firmly and uniformly to the patient's skin -in some cases the patient is asked to cough
- 6. Stethoscope or phonendoscope should be placed in strictly symmetrical points of the right and left sides of the chest. Auscultation begins with the anterior wall of the chest, from its upper part, in the supra- and subclavicular regions, and then the stethoscope should be moved downward and laterally.
- 7. The lungs are then auscultated in the same order from the posterior wall of the chest and in the axillary regions. In order to increase the area of auscultation between the scapulae, the patient should be asked to cross his arms on the chest and in this way to displace his shoulder-blades laterally from the spine, while for convenience of auscultation of the axillary regions he should place his hands on the back of the head.
- 8. Vesicular breathing (vesicular/ alveolar respiration) Respiratory sounds known as vesicular respiration arise due to vibration of the elastic elements of the alveolar walls during their filling with air in inspiration.The alveoli are filled with air in sequence.Therefore, the summation of the great number of sounds produced during vibration of the alveolar walls gives a long soft (blowing) noise that can be heard during the entire inspiration phase, its intensity gradually increasing. Alveolar walls still vibrate at the initial expiration phase to give a shorter second phase of the vesicular breathing, which is heard only during the first third of the expiration phase, because vibrations of elastic alveolar walls are quickly dampened by the decreasing tension of the alveolar walls.
- 9. Normal vesicular breathing is better heard over the anterior surface of the chest, below the 2nd rib, laterally of the parasternal line, and also in the axillary regions and below the scapular angle, i.e. at points where the largest masses of the pulmonary tissue are located.Vesicular breathing is heard worse at the apices of the lungs and their lowermost parts, where the masses of the pulmonary tissue are less abundant.
- 12. Physiological weakening of vesicular respiration occurs in patients with thicker chest wall due to excessively developed muscles or subcutaneous fat. Physiological intensification of vesicular respiration may be observed in patients with underdeveloped muscles or subcutaneous fat. Intensified vesicular breathing is characteristic of children with a thin chest wall, good elasticity of the alveoli and the interalveolar septa.This respiration is called “puerile respiration” (L puer child).Vesicular respiration is intensified during exercise; respiratory movements become deeper and more frequent. Physiological changes in vesicular respiration always involve both parts of the chest, and respiratory sounds are equally intensified or weakened at the symmetrical points of the chest.
- 13. Pathologically decreased vesicular respiration can be due to a significantly diminished number of the alveoli because of atrophy and gradual degradation of the interalveolar septa and formation of larger vesicles incapable of collapsing during expiration.This pathological condition is observed in pulmonary emphysema, at which the remaining alveoli are no longer elastic; their walls become incapable of quick distention and do not give sufficiently strong vibrations.
- 15. Decreased vesicular breathing can be due to inflammation and swelling of the walls in a part of the lung and decreased amplitude of their vibration during inspiration, which is characteristic of early acute lobar pneumonia. During the second stage of this disease, the alveoli of the affected part of the lung become filled with effusion and vesicular breathing becomes inaudible over this region.Vesicular breathing can be decreased also in insufficient delivery of air to the alveoli through the air ways because of their mechanical obstruction (e.g. by a tumour).Air admission to the alveoli can be decreased in patients with a markedly weakened inspiration phase (as a result of inflammation of the respiratory muscles, intercostal nerves, rib fracture, extreme asthenia of the patient and adynamia).
- 16. Vesicular respiration decreases also due to obstructed conduction of sound waves from the source of vibration (alveolar walls) to the chest surface, as, for example, in thickening of the pleural membranes or accumulation of air or fluid in the pleural cavity. If the amount of fluid or air in the pleural cavity is great, respiratory sounds are not heard. Conduction of sound to the surface of the chest may be absent in atelectasis of the lung due to complete obstruction of the lumen in the large bronchus.
- 17. Abnormally increased vesicular respiration can be heard during expiration or during both respiratory phases. Increased expiration depends on obstruction to the air passage through small bronchi or their contracted lumen (inflammatory edema of the mucosa, bronchospasm). Expiration becomes louder and longer.
- 18. Deeper vesicular respiration during which the inspiration and expiration phases are intensified, is called harsh (or coarse, rough) respiration. It occurs in marked and non-uniform narrowing of the lumen in small bronchi and bronchioles due to inflammatory edema of their mucosa (bronchitis).
- 19. Another type of pathological respiration is interrupted or cogwheel respiration. This vesicular respiration is characterized by short jerky inspiration efforts interrupted by short pauses between them; the expiration is usually normal. Interrupted breathing also occurs in non-uniform contraction of the respiratory muscles, e.g. when a patient is auscultated in a cold room, or when he has nervous trembling, or diseases of the respiratory muscles, etc. Interrupted breathing over a limited part of the lung indicates difficult passage of air from small bronchi to the alveoli in this region and uneven unfolding of the alveoli. Interrupted breathing indicates pathology in fine bronchi and is more frequently heard at the apices of the lungs during their tuberculosis infiltration.
- 20. Bronchial breathing/respiration (laryngotracheal respiration) 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 space of the larynx where it is set in a vortex motion. But since the vocal slit is narrower during expiration, the respiratory sound becomes louder, harsher and longer.This type of breathing is called laryngotracheal (by the site of its generation).
- 21. Bronchial breathing is well heard in physiological cases over the larynx, the trachea, and at points of projection of the tracheal bifurcation (anteriorly, over the manubrium sterni, at the point of its junction with the sternum, and posteriorly in the interscapular space, at the level of the 3rd and 4th thoracic vertebrae). Bronchial breathing is not heard over the other parts of the chest because of large masses of the pulmonary tissue found between the bronchi and the chest wall.
- 22. 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. Depending the origin there are three types of pathological bronchial respiration:
- 23. 1) Infiltrative type arises in consolidation of a pulmonary tissue (II stages of acute lobar pneumonia, infarct of lungs, tuberculosis) In such cases the alveolar walls do not vibrate, while consolidated airless pulmonary tissue becomes a good conductor of sound waves in laryngotracheal respiration to the surface of the chest wall.
- 24. 2) Cavitary type is auscultated above superficially posed smooth-bore lumen of the big diameter connected with a bronchus (an abscess, a tubercular cavern, bronchiectasias with an appreciable distention of bronchi)
- 25. 3) Atelectatic type it is observed in compression atelectasis (exsudative pleurisy of 1,5-3 litres), is auscultated at a column on high bound of a dullness where is compressiated lung, rarely passes for lin. axillaries anterior.
- 26. Amphoric respiration arises in the presence of a smooth-wall cavity (not less than 5-6 cm in diameter) communicated with a large bronchus. Sounds of this kind can be produced by blowing over the mouth of an empty glass or clay jar.This altered bronchial breathing is there called amphoric (Gk amphoeus jar). 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 the pleural cavity communicates with the external air. Stenotic respiration is exaggerated laryngotracheal breathing which is heard in cases with narrowed trachea or large bronchus (due to a tumour); it is heard mainly ay points where physiological bronchial breathing is normally heard.