Medium loud,low-pitched, clear,hollow sound with moderate duration heard over normal lung tissue.

TABLE 7-2

Inhaltsverzeichnis Show

Breath Sounds
What sound will you hear over lung tissue?
What type of lung sounds are heard with pneumonia?
Are lung sounds high pitched or low pitched?
What is the sound of normal clear lungs?

Sounds Produced by Percussion

Sound	Intensity	Pitch	Duration	Quality	Common Location
Tympany	Loud	High	Moderate	Drumlike	Enclosed, air-containing space
Resonance	Moderate to loud	Low	Long	Hollow	Normal lung
Hyperresonance	Very loud	Very low	Longer than resonance	Booming	Emphysematous lung
Dullness	Soft to moderate	High	Moderate	Thudlike	Liver
Flatness	Soft	High	Short	Flat	Muscle

From Potter PA, Weilitz PB: Pocket guide to health assessment, St. Louis, 2003, Mosby, p 43.

Breath Sounds

Auscultation

of lungs help determine the airway and alveolar integrity, ventilation and presence of abnormality.

There are two normal breath sounds. Bronchial and vesicular . Breath sounds heard over the tracheobronchial tree are called bronchial breathing and breath sounds heard over the lung tissue are called vesicular breathing. The only place where tracheobronchial trees are close to chest wall without surrounding lung tissue are trachea, right sternoclavicular joints and posterior right interscapular space. These are the sites where bronchial breathing can be normally heard. In all other places there is lung tissue and vesicular breathing is heard.

Method of Exam

Use the diaphragm of the stethoscope. Listen to the chest posteriorly, in axilla and front of chest similar to the way lungs were percussed. Follow the same routine, listen to breath sounds from top to bottom and compare sides by alternating corresponding sites. Listen to at least one complete respiratory cycle at each site. First listen with quiet respiration. If breath sounds are inaudible, then have him take deep breaths.

Note the intensity of breath sounds, symmetry, length of inspiration and expiration. Listen for the pause between inspiration, expiration and the quality of pitch of the sound. Compare the intensity of breath sounds between upper and lower chest in upright position. Compare the intensity of breath sounds from dependent to top lung in the decubitus position. Note the presence or absence of adventitious sounds.

Normal

The bronchial breath sounds over the trachea has a higher pitch, louder, inspiration and expiration are equal and there is a pause between inspiration and expiration.

The vesicular breathing is heard over the thorax, lower pitched and softer than bronchial breathing. Expiration is shorter and there is no pause between inspiration and expiration. The intensity of breath sound is higher in bases in erect position and dependent lung in decubitus position.

The breath sounds are symmetrical and louder in intensity in bases compared to apices in erect position. No adventitious sounds are heard.

Abnormal
Intensity of breath sounds, in general, is a good index of ventilation of the underlying lung. If the intensity increases there is more ventilation and vice versa. Breath sounds are markedly decreased in emphysema.

Symmetry: If there is asymmetry in intensity, the side where there is decreased intensity is abnormal.

Any form of pleural of pulmonary disease can give rise to decreased intensity.

Bronchial breathing anywhere other than over the trachea, right clavicle or right interscapular space is abnormal. Presence of bronchial breathing would suggest:

Consolidation
Cavitation
Complete alveolar atelectasis with patent airways
Mass interposed between chest wall and large airways
Tension Pneumothorax
Massive pleural effusion with complete atelectasis of lung

In all these conditions, there are no ventilation into alveoli and the sound that is heard originates from bronchi and is transmitted to the chest wall.

Experienced physicians could discriminate between consolidation and cavitation by noting the quality of bronchial breathing. In consolidation, the bronchial breathing is low pitched and sticky and is termed tubular type of bronchial breathing. In cavitary disease, it is high pitched and hollow and is called cavernous breathing. You can simulate this sound by blowing over an empty coke bottle. In tension pneumothorax bronchial breath sounds has a metallic quality and is called amphoric breathing.

Caution:

Make sure you warm the stethoscope before placing on patient's chest. Rub the metallic part of the stethoscope and warm it up.
Don't make the patient hyperventilate by making them take deep breathes too many times. Give rest in between. Instruct the patient to take a deep breath only when you have your stethoscope on their chest.

Example:

Breath sounds are decreased over the area of dullness. That does not help us distinguish between pleural effusion and mass lesion. Let us see whether the next step will help?

What sound will you hear over lung tissue?

Resonant sounds are low pitched, hollow sounds heard over normal lung tissue. Flat or extremely dull sounds are normally heard over solid areas such as bones.

What type of lung sounds are heard with pneumonia?

Your doctor will listen to your lungs with a stethoscope. If you have pneumonia, your lungs may make crackling, bubbling, and rumbling sounds when you inhale.

Are lung sounds high pitched or low pitched?

Normal lung or vesicular breath sound: A doctor can hear this sound over most of the chest with a stethoscope, a device for listening to a person's internal body sounds. Vesicular breath sounds occur when air flows into and out of the lungs during breathing. The sound is soft, low pitched, and rustling in quality.

What is the sound of normal clear lungs?

Vesicular sounds are soft, blowing, or rustling sounds normally heard throughout most of the lung fields. Vesicular sounds are normally heard throughout inspiration, continue without pause through expiration, and then fade away about one third of the way through expiration.