Abnormal Breath Sounds

Crackles (or rales)are caused by fluid in the small airways or atelectasis. Crackles are referred to as discontinuous sounds; they are intermittent, nonmusical and brief. Crackles may be heard on inspiration or expiration. The popping sounds produced are created when air is forced through respiratory passages that are narrowed by fluid, mucus, or pus. Crackles are often associated with inflammation or infection of the small bronchi, bronchioles, and alveoli. Crackles that don't clear after a cough may indicate pulmonary edema or fluid in the alveoli due to heart failure or adult respiratory distress syndrome (ARDS).

Crackles are often described as fine, medium, and coarse. Fine crackles are soft, high-pitched, and very brief. You can simulate this sound by rolling a strand of hair between your fingers near your ear, or by moistening your thumb and index finger and separating them near your ear. Coarse crackles are somewhat louder, lower in pitch, and last longer than fine crackles. They have been described as sounding like opening a Velcro fastener.

Wheezes are sounds that are heard continuously during inspiration or expiration, or during both inspiration and expiration. They are caused by air moving through airways narrowed by constriction or swelling of airway or partial airway obstruction.

Wheezes that are relatively high pitched and have a shrill or squeaking quality may be referred to as sibilant rhonchi. They are often heard continuously through both inspiration and expiration and have a musical quality. These wheezes occur when airways are narrowed, such as may occur during an acute asthmatic attack. Wheezes that are lower-pitched sounds with a snoring or moaning quality may be referred to as sonorous rhonchi. Secretions in large airways, such as occurs with bronchitis, may produce these sounds; they may clear somewhat with coughing.

Pleural friction rubs are low-pitched, grating, or creaking sounds that occur when inflamed pleural surfaces rub together during respiration. More often heard on inspiration than expiration, the pleural friction rub is easy to confuse with a pericardial friction rub. To determine whether the sound is a pleural friction rub or a pericardial friction rub, ask the patient to hold his breath briefly. If the rubbing sound continues, its a pericardial friction rub because the inflamed pericardial layers continue rubbing together with each heart beat - a pleural rub stops when breathing stops.

Stridor refers to a high-pitched harsh sound heard during inspiration.. Stridor is caused by obstruction of the upper airway, is a sign of respiratory distress and thus requires immediate attention.

If adventitious sounds are heard, it is important to assess:

their loudness, timing in the respiratory cycle,

location on the chest wall, persistence of the pattern from breath to breath, and

whether or not the sounds clear after a cough or a few deep breaths.o secretions from bronchitis may cause wheezes, (or rhonchi), that clear with coughingo crackles may be heard when atelectatic alveoli pop open after a few deep breaths

Accessory muscles of respiration – muscles other than the diaphragm and intercostal muscles that may be used for labored breathing. The sternocleidomastoid, spinal, and neck muscles may be used as accessory muscles of respiration; their use is a sign of an abnormal or labored breathing pattern.

Adventitious breath sounds – abnormal breath sounds heard when listening to the chest. Adventitious sounds may include crackles or rales, rhonchi or wheezes, or pleural friction rubs. Adventitious sounds do not include sounds produced by muscular activity in the chest wall or noises made by a stethoscope on the chest wall.

Ataxic breathing– also known as Biot's breathing, is characterized by unpredictable irregularity.

Barrel chest– a condition characterized by increased anterior-posterior chest diameter caused by increased functional residual capacity due to air trapping from small airway collapse. A barrel chest is frequently seen in patients with chronic obstructive diseases, such as chronic bronchitis and emphysema.

Cheyne-Stokes respirations– a breathing pattern characterized by a period of apnea, followed by gradually increasing depth and frequency of respirations.

Consolidation– the replacement of air in the lungs with fluid or a mass.

Crackles– an adventitious breath sound heard on ausculating the chest, produced by air passing over airway secretions. A crackle is a discontinuous sound, as opposed to a wheeze, which is continuous. Crackles are known as fine or coarse and are also known as rales.

Fremitus– a vibration felt while a patient is speaking and the examiner's hand is held against the chest.

Intercostal retractions – visible use of the muscles between the ribs (intercostal muscles) to aid in breathing. Intercostal retractions are a sign of labored breathing.

Kussmal breathing– a very deep gasping type of respiration associated with severe diabetic acidosis and coma.

Kyphosis– a deformity in the normal posterior shape of the spine, producing a humpback appearance.

Nasal flaring – intermittent outward movements of the nostrils with each inspiration; indicates an increase in the work needed to breathe.

Pleura– a serous membrane covering both lungs and the walls of the thorax and diaphragm.

Pursed lip breathing – partial closing of the lips to allow air to be expired slowly; used by patients with chronic obstructive pulmonary disease.

Sibilant rhonchi– a high pitched wheeze; musical and squeaky adventitious breath sound.

Scoliosis – a lateral curvature of the spine.

Sonorous rhonchi -a lower pitched wheeze; snoring or moaning adventitious breath sound.

Stridor – a high-pitched harsh sound heard during inspiration. Stridor is caused by obstruction of the upper airway.

Wheeze -an adventitious or abnormal breath sound heard when listening to the chest as a person breathes. Wheezes are continuous and musical sounding, and usually caused by airway obstruction from swelling or secretions. Wheezes can be high or low pitched, and are also known as rhonchi.