Pediatric emergency medicine trisk 4067 4067
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Although wheezing and stridor are very common presentations in
children with intercurrent viral illnesses, structural problems should be
considered in children with recurrent presentations or significant
respiratory distress that does not respond to typical therapies.
Radiographic studies may not reveal the cause of tracheal obstruction,
since these are often dynamic processes. Direct laryngoscopy or
bronchoscopy may be necessary.
Current Evidence
Tracheal obstruction may be produced by stenosis or lesions within the lumen of
the trachea (Fig. 124.1 ), in the wall of the trachea, or by extrinsic compression.
One of the most common causes of intrinsic obstruction in children is an
aspirated foreign body (please see Chapter 32 Foreign Body: Ingestion and
Aspiration for details). Other causes include congenital anomalies such as
subglottic stenosis, laryngomalacia, and vocal cord paralysis. Acquired causes
include subglottic stenosis after tracheostomy or prolonged intubation, viral or
bacterial tracheitis or any process that causes significant mucosal edema
particularly in an infant with small baseline airway diameter, or rarely a spaceoccupying lesion such as a hemangioma or primary tracheobronchial tumor.
Tracheomalacia, sometimes complicating lung disease of prematurity and
prolonged intubation, is characterized by a floppy trachea that collapses during
expiration when the intrathoracic trachea is compressed by the positive
intrathoracic pressure. Laryngomalacia, or tracheomalacia outside the thoracic
inlet, may produce obstruction during inspiration when the negative intraluminal
pressure transmitted from the chest causes the floppy wall to collapse.
Tracheomalacia often occurs in infants born with tracheoesophageal fistula (TEF)
or other intrinsic anomalies. Extrinsic compression can occur from mass lesions
(Table 124.1 ) or as a result of anomalous arteries.
