Adventitious lung sounds are a group of additional noises that doctors may hear during auscultation. These noises are abnormal and can be a sign of an underlying medical condition.
The sounds a person hears as they breathe are important to understand and learn. Whether you are a Respiratory Therapist, physician or student, knowledge of normal and abnormal breath sounds is essential.
Rhonchi
Abnormal breath sounds occur when the airways are obstructed, blocked or filled with fluid. This is often due to a respiratory condition such as asthma, chronic bronchitis, COPD or heart failure.
Rhonchi are continuous low-pitched, rattling lung sounds that sound a lot like snoring and can be caused by obstruction or secretions in the larger airways such as the bronchi. They are frequently heard in patients with pneumonia, bronchiectasis, chronic obstructive pulmonary disease (COPD), chronic bronchitis or cystic fibrosis.
Adventitious lung sounds are the most common abnormal breath sounds that can be found with a stethoscope. These include crackles, rhonchi and wheezes. These are called adventitious sounds because they are not the expected breath sounds that occur when a person breathes in and out. Using a stethoscope to listen to breath sounds can help physicians determine the cause of respiratory problems and monitor their progress. They also can be used to identify the need for suctioning.
Wheezes
Wheezes are relatively high-pitched whistling noises produced by turbulent flow of air through narrowed or compressed segments of small airways. They are heard during inspiration (stridor) and during expiration.
Wheezing is most common in asthma, which is an inflammation of the lungs, but it can be found in other respiratory disorders. Some of these are bronchitis, cystic fibrosis, chronic obstructive pulmonary disease (COPD), and pneumonia.
Pneumonia can be caused by bacteria or viruses, and is most common in infants. Antibiotics won’t help with these types of illnesses, so a healthcare provider may recommend using a short-term inhaled bronchodilator to control wheezing until the condition clears up.
Adventitious lung sounds are often difficult to distinguish from normal breathing sounds by auscultation. Consequently, health workers often use combined terms of crackles and wheezes in their clinical practice. However, this approach is prone to misinterpretation. Hence, the use of more specific categories should be encouraged.
Stridor
Stridor is a high-pitched sound that comes from the larynx or the trachea (windpipe). It can be heard when you breathe in, or when you breathe out.
The sounds are often caused by a blockage in the upper airway. It can be very serious and cause breathing problems.
Children are more likely to get stridor because their airways are shorter and narrower than those of adults. It can be a sign of an underlying problem, like croup or foreign body aspiration, so it’s important to find out what’s wrong.
Doctors usually know what’s causing stridor by listening to the lungs, asking about the patient’s medical history, and doing a physical exam. They also check for a heart murmur and an electrocardiogram.
Pleural Rubs
A pleural rub is a creaking or grating sound heard in the chest when two swollen or inflamed pleura (tissues surrounding your lungs) rub together during respiration. This sound is usually produced in pleurisy (inflammation of your pleura) but can be caused by many conditions that affect your lungs.
It is a nonspecific finding with a wide differential that can lead to rapid diagnosis and treatment. Common causes of a pleural rub include pneumonia, pulmonary embolism, and pleuritis.
Lung sounds are a key component of lung auscultation and are classified by their pitch and intensity when they occur during inhalation and exhalation. They are easy to identify using stethoscope auscultation and may also be heard with a tympanic membrane stethoscope.