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Professionalization
of Exercise Physiologyonline

An international electronic
journal for exercise physiologists
ISSN 1099-5862

Vol 4 No 8  August 2001

 

Auscultation: Listening to Determine Dysfunction
Mark Kaelin, MS,CSCS
Exercise Physiologist
Pulmonary Rehabilitation Program Coordinator 
Southern Indiana Rehabilitation Hospital
New Albany, IN


See also: Physical Assessment: An Often Over-Looked Portion of Exercise Testing and Prescription



Auscultation is the process of listening for sounds produced in the body to identify normal or abnormal sounds and to aid in diagnosis. Exercise Physiologists cannot diagnose conditions.  Auscultation is a assessment tool to determine the limiting factors to exercise. This article is limited to those sounds generated in the lungs. However, before we can cover how to ausculate, a brief review of the respiratory system and the thorax is needed. 

Anatomy of the Respiratory System and Thorax 
The respiratory system can be separated into two tracts (upper and lower) The upper respiratory tract is comprised of the nose, paranasal sinuses, pharynx, and the larynx.  The purpose of this tract is to purify, warm, and humidify ambient air before it reaches the gas exchange units. The lower respiratory tract begins with the trachea, the right main bronchus which divides into three lobar or divisions of the lung (upper, middle, and lower), the left main bronchus which divides into two lobes (upper and lower), followed by the bronchioles, and terminating at the alveoli (air sacs). In this tract, there are approximately 23 generations of airways; the first 16 are conducting airways while the last seven are respiratory airways ending in approximately 300 million alveoli, which form the gas exchange surface (1).
 

Figure 1. Anatomy of the Respiratory System


The bony thorax is an osseo-cartliginous cage containing and protecting the organs of respiration and circulation. Its skeletal framework is comprised of the sternum, coastal cartilage, ribs, and 12 thoracic vertebrae. Auscultation of the lungs involves the thorax and the lower respiratory tract, it’s imperative that exercise physiologists are familiar with anatomy and anatomical landmarks so one knows where and what they are listening to. The trachea is located at the base of the neck and extends 10-12 cm ( 3.7 - 4.5 inch) to the main carina; a keel shaped ridge at the lower end of the trachea separating the openings of the left and right bronchus (2, 4-6). The bronchi can be auscultated at the upper manubrium. 
 

Figure 2. Anterior View of the Thorax

 

Listening to the Lungs 

The lungs are auscultated with the diaphragm on the chest piece of a stethoscope with the patient breathing slowly and deeply thorugh their mouth. The anatomical sites for lung auscultation are illustrated in below. 
 

Figures 3 and 4. Sites for Auscultation of the Lungs
 

There are some common errors to avoid:
1. Listening to breath sounds through a patients gown or clothes.
2. Allowing tubing to rub against bed rails or patient’s clothes.
3. Interpreting chest hair sounds as adventitious* sounds.
4. Auscultating on the convenient places only (3, 7).
*Adventitious sounds: added sounds, or those superimposed on a patient's                      underlying breath sounds that usually indicate disease.

Normal breath sounds consist of those heard over the entire lung field and consist of an inspiratory and expiratory phase. They are classified as: 

Tracheal: These breath sounds are high-pitched and loud, with a harsh and hollow (or "tubular) quality. The inspiratory and expiratory phases are of equal duration, and there is a definite pause between phases. Tracheal breath sounds usually have very little clinical usefulness.

Bronchial: Normally heard over the upper manubrium, these breath sounds directly reflect turbulent airflow in the main-stem bronchi. They are loud and high-pitched but not quite as harsh and hollow as tracheal breath sounds, the expiratory phase is generally longer than the inspiratory phase, and there is usually a pause between the phases.

Bronchovesicular: These breath sounds are normally heard in the anterior first and second intercostal spaces and posteriorly between the scapulas, where the main-stem bronchi lie. The inspiratory and expiratory phases are about equal in duration, with no pause between phases. Bronchovesicular sounds are soft and less harsh than bronchial breath sounds and have a higher pitch than vesicular sounds.

Vesicular: Audible over peripheral lung fields, these breath sounds are soft and low-pitched, without the harsh, tubular quality of bronchial and tracheal breath sounds. The inspiratory phase is about three times longer than the expiratory, with no pause between phases (7).

Breath sounds are considered abnormal if they are heard outside their usual location in the chest or if they are qualitatively different from normal breath sounds (e.g. decreased or absent). They are divided into two categories: (1) continuous; and (2) non-continuous lung sounds. 

The program that I work at utilizes the pulmonary nomenclature developed and adopted by the American Thoracic Society and the American College of Chest Physicians, as published in the Essentials of Cardiopulmonary Physical Therapy (3). In this document, all continuous adventitious sounds are referred to as wheezes and described as either high-pitched or low pitched. Wheezes represent airway obstruction which can be caused by broncho-constriction of smooth muscle or the presence of mucus. When a wheezes occur, it is significant. They are most common with expiration. However, they can occur during inspiration and this indicates that a severe airway obstruction is present.

Discontinuous adventitious sounds are classified as either:

1. Crackles sound like brief bursts of popping bubbles. They are most commonly associated with the sudden opening of closed airways. 
2. Pleural Rubs are an indication of pleural inflammation and sounds like two pieces of sandpaper rubbing together throughout each inspiration and expiration (3).
Exercise physiologists can become proficient at auscultation by practicing on friends and family.  There are also numerous web site that offer auscultation tutorials. For example, 
http://www.wilkes.med.ucla.edu/inex.htm 
http://www.medinfo.ufl.edu/year1/bcs/clist/chest.html#AA11
Why is This Important?
Exercise physiologists work in a variety of settings.  The most common are clinics, fitness centers, and businesses to name a few. They are asked to work with a variety of people with a variety of conditions. I have been a practicing exercise physiology for five years. In that time, my ability to auscultate has improved a great deal.  However, I’ll never be as good as a physician and, fortunately, I do not need to be. I do need to be able to use my physical senses to assess how my patient or client is responding to exercise stress. 

As an example, a 32-year-old female presents at your gym. In her medical history, you notice she reports asthma as a child. When questioned she states, “I outgrew it and it doesn’t bother me anymore." Over several weeks at your facility, you notice that she is disproportionately short of breath and frequently has coughing spells with aerobic exercise. What do you think might be going on? It could be that exercise is a trigger for her asthma. One way to provide her with more information would be to auscultate when she is experiencing these symptoms to see if she is wheezing. Will you diagnose asthma, No!  But you can provide her with information to report to her physician so she can be treated possibly saving her life and retaining a member for your facility. 



References

1. ACSM Resource Manual. (1998). (3rd Edition). Philadelphia, PA: Lippincott Williams and Wilkins
2. R. L. Wilkins, S.J. Krider and R. L (1995). Sheldon Clinical Assessment in Respiratory Care. St. Louis: Mosby. 
3. E. A.  Hillegas and H. S. Sadowsky. (1994). Essentials of Cardiopulmonary Physical Therapy. Philadelphia, PA: W. B. Saunders Comapny. 
4. Grays H. (1901). Grays Anatomy. Philadelphia, PA: Running Press.
5. Taber’s Cyclopedic Medical Dictionary. (2001). (19th edition). Philadelphia, PA: F. A. Davis Company. 
6. Marieb EN. (1988). Essentials of Human Anatomy and Physiology. Menlo Park, CA: Benjamin-Cummings Company.
7. http://www.wilkes.med.ucla.edu/inex.htm accessed 8/02/01. 
 


Please forward any questions and comments to the author at mkaelin@sirh.org
Copyright ©1997-2001 American Society of Exercise Physiologists. All Rights Reserved.

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