Introduction:
Although several diagnostic tools are available, auscultation is the most commonly used term today. Auscultation refers to the process of listening to sounds during a lung examination. It is typically done to note the type of breathing and the presence of foreign objects. A physician must ensure the patient assumes a comfortable, relaxed position.
Breath sounds are created by turbulent airflow. During inspiration, air moves into progressively smaller airways with the alveoli as its final location. As the air hits the walls of these airways, turbulence is created, producing the sound. During expiration, air moves in the opposite direction towards progressively larger airways, creating less turbulence. Thus, normal expiratory breath sounds are quieter than inspiratory breath sounds.
What Are the Abnormal Breath Sounds?
The abnormal breath sounds are
Crackles: These are discontinuous, non-musical, brief sounds heard more commonly on inspiration. It can be classified as high-pitched, soft, or low-pitched, loud sounds. It can be heard due to moving secretion in the rapidly opening airways. The most common cause is asthma.
Wheeze: These are continuous, high-pitched, hissing sounds normally heard during expiration but sometimes on inspiration. It is produced when air flows through airways, narrowed by secretions, foreign bodies, or obstructive lesions. The common causes are asthma, chronic obstructive pulmonary disease, chronic bronchitis, and pulmonary edema.
Rhonchi: These are continuous, low-pitched musical sounds similar to wheezes. It usually reflects obstruction of the larger airways by secretions.
Stridor: It is an inspiratory musical wheeze, heard loudest over the trachea during inspiration. It typically reflects an obstructed trachea or larynx, representing a medical emergency requiring immediate intervention.
What Is Rhonchi?
Rhonchi is a low-pitched sound that usually occurs in the large airways. It often mimics the sound of snoring. It is usually evaluated in an upright, prone, or decubitus position. Rhonchi can be generalized or localized, inspiratory or expiratory.
Diffuse or generalized rhonchi suggest a disease with generalized airway obstruction, such as asthma or COPD (chronic obstructive pulmonary disease). Localized rhonchi would suggest obstruction of any etiology, such as foreign body, tumor, or mucus. Inspiratory rhonchi can be commonly seen in asthmatics but uncommon in COPD patients. However, an expiratory rhonchus implies obstruction to intrathoracic airways, and it is the most pronounced breath sound. Loud audible inspiratory rhonchi are also known as stridor.
What Causes Rhonchi?
Rhonchi may be caused by airway obstruction due to either mucus, fluid, or other secretions.
Various conditions may cause blockage of the airways, such as
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Chronic bronchitis.
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Cystic fibrosis.
What Is the Basic Difference Between Rhonchi and Rales?
Rhonchi is a low-pitched sound caused due to blockage of the airways that may occur specifically during exhalation. Coughing or suctioning of the mucus secretions may reduce rhonchi to significant levels. In contrast, rale is a high-pitched crackling sound that usually occurs during inhalation. Coughing or suctioning of mucus does not affect rales. It can be classified as fine, coarse, dry, and moist.
The most common conditions that may lead to the production of rales or bibasilar crackles are
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Interstitial lung disease.
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Asthma.
What Are the Diagnosis of Rhonchi?
Apart from listening to the breath sounds on auscultation, a definitive diagnosis can be made based on the following:
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Imaging: Chest X-ray or computed tomography (CT) scan can help diagnose infections or certain lung conditions.
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Pulmonary Function Test or Spirometry: It is a physiological test that measures how an individual inhales or exhales volumes of air as a function of time. It assesses the integrated mechanical function of the lung, chest wall, and respiratory muscles by measuring the total volume of air exhaled from a full lung or total lung capacity (TLC) to maximal expiration or residual volume (RV). It is a technique used to measure airflow in and out of the lungs. It records lung volumes and capacities defined by the respiratory process.
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Sputum Culture: To look for any microbial pathology present in the sputum sample.
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Bronchoscopy with Bronchoalveolar Lavage: Bronchoalveolar lavage (BAL), also known as a bronchoalveolar wash, is a minimally invasive procedure by which cells and other components of the bronchi and alveoli are obtained. It involves the instillation of sterile normal saline into the tracheobronchial tree. The introduction of a bronchoscope typically facilitates it into the airways.It is an endoscopic method to visualize the airways directly using a thin, light-weighted, flexible tube that can be advanced quickly into the small airways and bronchioles. It can be used as a therapeutic agent by using small amounts of sterile normal saline to dislodge heavy mucous plugs in the small, distal airways.
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Complete Blood Count: White cell count may be marginally raised in pneumonia caused by atypical organisms, whereas neutrophil leucocytosis of more than 15x109 per liter favors a bacterial etiology. A very high or low white cell count may be seen in severe pneumonia. C-reactive protein is typically elevated.
What Is the Management of Rhonchi?
The management of rhonchi typically involves immediate symptomatic relief or eradication of the underlying causes. Symptomatic relief can be achieved by administering oxygen, which is beneficial for patients with heavy mucus plugs in the small, distal airways. Other methods of providing symptomatic relief include nasopharyngeal suctioning and increased intravenous fluid administration.
Medications that may help in providing symptomatic relief and treating the underlying causes are:
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Bronchodilators: Drugs that relax the tubules' muscles and dilate the airways, such as short and long-acting beta-agonists and anticholinergics.
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Corticosteroids: Drugs that help to reduce the inflammation of the airways.
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Combined Inhalers: Bronchodilators and corticosteroids combined as one inhaler.
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Antibiotics: Drugs to fight against bacterial infection.
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Mucolytics: Helps in lysis or breaking down the secretions such as guaiphenesin.
Conclusion:
Rhonchi is a low-pitch abnormal breath sound, typically more pronounced during expiration. Breath sounds are created by turbulent airflow. It is usually caused by mucus, fluid, or other secretions obstructing the airways. Various clinical pulmonary conditions may cause an obstructed airway. A thorough physical examination with detailed history and listening to breathing sounds may help diagnose the condition. The physician may further ask for chest radiography and pulmonary function tests for a definitive diagnosis. Early intervention with proper diagnosis may be beneficial for the patient's longevity.
