Stridor is noisy musical breathe sounds. It is a symptom, not a diagnosis, and it is very important to find the unseen underlying causes.
Children have small and narrow airways and hence are more prone to noisy breathing. Stertor is noisy breathing related to nasal and oropharyngeal pathologies. Stridor is due to pathologies involving the larynx and trachea. Wheezing is typical of a bronchial pathology. When the noisy breathing is worse during sleep, the cause is in the oropharynx. When the noise is more when the patient is awake, the cause is in the larynx or trachea.
Stridor could be high pitched and musical (crowing) or low pitched and harsh (croaking). In children, acute stridor could accompany respiratory tract infections, trauma or foreign body inhalation and chronic stridor usually occurs with congenital conditions. Stridor in adults is much less common, though chronic stridor in adults often indicates serious underlying pathology.
Stridor can be heard during inspiration or expiration or could be biphasic. Inspiratory stridor is seen in an obstruction above, at, or below the larynx. Sometimes, in a worse scenario, there could be multiple levels or sites of obstruction. Expiratory stridor is seen in tracheal or bronchial pathologies and a biphasic stridor is typical of a glottic or subglottic obstruction.
The evaluation of a stridorous child begins by checking the patient’s history for whether the onset of stridor was gradual or sudden, relation with body position, birth history and previous intubation, the relationship of stridor to feeding, neck trauma and careful questioning for aspirated foreign bodies. In adults, smoking history could be associated with cancer of the larynx.
The gold standard to diagnose the cause of the stridor is endoscopy (transnasal flexible laryngobronchoscopy). Following a dynamic exam of the airway (that mimics the airway when the patient is awake), a direct evaluation of the aerodigestive tract using rigid optics is performed. A biopsy, CT scan and an MRI are done for tumors.
The therapy options for stridor vary greatly depending on the cause, which is determined by the evaluations performed by the doctor. The Non Invasive Ventilation NIV techniques (CPAP-Continuous Positive Airway Pressure or BIPAP-Biphasic Positive Airway Pressure) are used frequently, wherein oxygen is passed under pressure, with the help of a well-fitting mask on the face.
Various causes of stridor in infants and children have been discussed elsewhere in the glossary. Increasing stridor in post operative cases could be due to airway edema (swelling) or granulations (tissue of the scar process) at the operative site. They respond well to systemic and inhalational steroids.
Tumors are discussed in a multidiscipline tumor board to decide the best possible treatment suited for each patient.