A symptom characterized by noisy breathing because of
turbulent flow in the narrowed airways indicating partial obstruction of the
upper airway, glottis, or trachea. Congenital stridor is a symptom rather
than a syndrome.
Depends on the underlying cause.
Fixed or variable partial obstruction of the upper
airway, glottis, or trachea may change the air flow pattern from laminar to
turbulent, which results in noisy breathing or stridor. Extrathoracic
obstructions usually are associated with inspiratory stridor, whereas
intrathoracic lesions usually result in expiratory stridor, and (sub)glottic
stenoses may result in biphasic (inspiratory and expiratory) stridor. Causes
of congenital stridor are variable and can be divided into four categories:
supralaryngeal, laryngeal, tracheal, and nonanatomical. They may include
tracheoesophageal fistula, laryngomalacia, narrowing of the mainstem
bronchus, Pierre-Robin syndrome, dysfunction of cranial nerves IX to XII,
curled epiglottis, congenital subglottic stenosis, laryngotracheal cleft,
epipharyngeal fibroma, vascular rings, and bronchogenic cysts. In severe
cases, gastroesophageal reflux may lead to stridor.
Patients usually present with stridor starting just after
birth or shortly thereafter (first 4-6 weeks of life), feeding
difficulties, frequent coughing, and recurrent aspirations. The diagnosis is
based on the clinical finding of the characteristic breath sounds. Clinical
circumstances may give an idea about the etiology (association with position
and feeding, persistent versus intermittent, abnormal phonation, foreign body
exposure, presence of other congenital abnormalities).
Laryngo-broncho-esophageal examination usually reveals the exact cause of the
symptom. Check the percentiles for weight and height because increased
respiratory work may lead to increased energy requirements with growth retardation.
Congenital stridor is a symptom rather than a
syndrome, so the cause of the stridor must be explored. The most common
cause of inspiratory stridor in the neonatal period is laryngomalacia, which
accounts for approximately three fourths of all cases. Stridor generally
improves in the prone position with the head up. Laryngomalacia usually
requires no therapy and disappears spontaneously around 1 year of age. Rarely,
in patients with severe obstruction, supraglottoplasty may be required.
Unilateral vocal cord paralysis is probably the second most common cause of
stridor in the neonatal period. It is either congenital or acquired (related
to cardiothoracic surgery or birth trauma). Incomplete canalization of the
subglottic area and cricoid rings is the anatomical correlate in congenital
subglottic stenosis, while acquired subglottic stenosis is most often caused
by prolonged intubation (often related to an endotracheal tube with a
diameter that is too big). Severe episodes of airway obstruction may require
resuscitation with intubation and/or tracheo(s)tomy. Ask about associated
features such as cyanosis, increased respiratory efforts (indrawings),
tachypnea, and apnea to determine the severity of the stridor. The most
common cause of expiratory stridor in the neonatal period is tracheomalacia,
which is caused by a loss of the stability of the tracheal ring cartilages
and results in persistent stridor. However, tracheal collapse also can be
caused by external compression (double aortic arch, vascular rings, slings).
An increased risk of obstructive sleep apnea has been reported ...