Bronchial breath sounds are auscultated over the first and second intercostal space of the anterior chest wall. Normal bronchial breath sounds indicate air movement through the tracheobronchial tree. The tracheobronchial tree includes the trachea and the bronchi. These sounds are hollow, loud, and high-pitched compared to vesicular breath sounds. Bronchial breath sounds shouldn’t be heard in peripheral lung tissue. Bronchial breath sounds heard in the peripheral lung tissue should be considered adventitious lung sounds. 
 



Course crackles indicate fluid or mucus buildup in airway passages. Atelectasis may also cause crackles in the airway. Crackles are heard as air moves through narrowed airway passages. Fluid and/or mucus buildup results in the narrowing of small airway passages. Crackles are typically heard in the bases of the lungs, but can be heard in the upper lobes of the lungs depending on severity. Coarse crackles are lower pitched and louder than fine crackles. 
 



Course crackles indicate fluid or mucus buildup in airway passages. Crackles are commonly referred to as “rales.” Congestive heart failure, chronic obstructive pulmonary disease, pulmonary fibrosis, and atelectasis can all cause crackles to be heard in the lungs. Crackles are heard as air moves through narrowed airway passages. Fluid and/or mucus buildup results in the narrowing of small airway passages. Crackles are typically heard in the bases of the lungs, but can be heard in the upper lobes of the lungs depending on severity. Fine crackles are high pitched and brief compared to coarse crackles. 
 

Diminished breath sounds can be caused by air or fluid obstruction, hyperinflation of the lung, increased tissue build up in the chest wall, or reduced airflow. Diminished breath sounds can indicate a multitude of chronic and acute respiratory conditions. Some of these conditions include heart failure, chronic obstructive pulmonary disease, emphysema, pleural effusion, or a pneumothorax. The mechanism of injury or nature of illness the patient is presenting with will determine the cause of the diminished breath sounds. It is important to note that some patients with chronic respiratory conditions will always have diminished breath sounds.

Expiratory wheezing indicates constriction of the airway passages. This can be caused by chronic obstructive pulmonary disease, emphysema, anaphylaxis, asthma, allergic reaction, or any other respiratory disease that result in construction of airway passages. Wheezing can be heard during exhalation or inhalation, depending on severity. Typically, wheezing heard during expiratory and inspiratory phases indicates severe airway constriction. Rapid intervention must occur to prevent complete airway obstruction. Expiratory wheezes alone often indicate mild or moderate airway compromise, that often resolve with little to no intervention. 

Pleural rub sounds are isolated sounds that are caused by inflamed lung tissue sliding against each other. These sounds are often described as coarse, similar to sandpaper rubbing against itself. Pneumonia, pleurisy,  and pulmonary embolism can cause pleural rub sounds. Pain can be associated with pleural rub sounds; oftentimes pinpoint pain that increases on inspiration will occur. Coughing will not cause cessation or change in pleural rub sounds. 

Rhonchi lung sounds are described as a low pitched wheeze. This sound indicates the presence of some form of secretion (such as fluid or mucus) in the airways. Typically rhonchi are heard in the smaller passages the lower airways, but they can also be heard in the upper, larger airways. Some respiratory conditions that can cause rhonchi include: chronic obstructive pulmonary disease, pneumonia, chronic bronchitis, and cystic fibrosis. These sounds are low pitched, often described as a “snoring” sound.

Stridor is an inspiratory wheeze that is high pitched. Stridor indicates a partial upper airway obstruction, that can be caused by a foreign body or inflammation. Stridor is commonly seen in children with foreign body obstructions, croup, and epiglottitis. Stridor can easily progress to complete airway obstruction, and rapid intervention must occur to ensure airway patency. 

Vesicular breath sounds are considered “normal” breath sounds. Vesicular breath sounds are described as a soft rustling noise. These sounds are auscultated over lung tissue. The expiration phase is shorter than the inspiration phase in vesicular breath sounds. The inspiration and expiration phases have no pause in between them, compared to bronchial breath sounds which do have small pause in between phases. 

 

Resources

Caroline, N. L., Elling, B., & Caroline, N. L. (2014). Nancy Carolines emergency care in the streets. Burlington, MA: Jones and Bartlett Learning.