Pediatric emergency medicine trisk 1018

Tracheal obstruction can be caused by a variety of mechanical, infectious, and
congenital abnormalities. Clinicians must rapidly assess the cause of obstruction
while working toward stabilization of the airway. Surgical causes of obstruction
require prompt consultation and coordination of care.
Clinical Considerations
Clinical Recognition. Tracheal compromise produces symptoms that vary from
mild to severe, depending on the degree of obstruction present. When symptoms
are mild, an underlying cause may not be evident. Occasional episodes of
respiratory infection that are believed to result from croup or bronchiolitis may be
the only symptom. Stridor, wheezing, or harsh barky cough occurs in patients
with more significant obstruction, and a history of frequent hospitalizations for
respiratory compromise may be obtained.
Severe tracheal compromise is usually manifested by a history of stridor at rest.
Progressive cyanosis and apneic episodes may occur. On examination, a child
with obstruction caused by extrinsic compression often has wheezing or stridor
throughout the respiratory cycle. In contrast, a patient with the floppy trachea of
tracheomalacia often wheezes only during expiration.
Radiographic evaluation of the stable patient should begin with PA and lateral
chest radiographs, ideally obtained at full inspiration and again at full expiration.
Lateral radiographs of the neck may be useful in showing an edematous epiglottis
in patients with suspected epiglottitis. Mass lesions will require cross-section
imaging (e.g., computed tomography [CT]) for evaluation. Bronchoscopy is often
indicated to evaluate obstructive lesions, whether in the lumen, the wall, or
extrinsic to the wall of the trachea.
Management. If the patient has a life-threatening airway obstruction, he or she
should receive airway management as outlined in Chapters 7 A General
Approach to the Ill or Injured Child and 8 Airway . A coordinated effort between
the emergency department (ED) care team, the surgeon, and the anesthesiologist
or critical care physician may be necessary to establish an airway by endotracheal
intubation, bronchoscopy, or tracheotomy. Intubation of the airway to within a
short distance of the carina supports most patients with critical obstruction

secondary to lesions extrinsic to the trachea or within the tracheal wall. Such
patients require admission to an intensive care unit with ventilator capability.
Lesions within the lumen will likely require endoscopic management in an
operating room, and early involvement of an experienced surgeon is
recommended.


Many inflammatory processes within the trachea are controlled with antibiotics
and respiratory care without airway manipulation or surgical intervention.
Treatment in these cases includes the administration of humidified oxygen and
inhaled racemic epinephrine, combined in some cases with the administration of
oral, intramuscular, or intravascular dexamethasone. Although laryngoscopy and
tube delivery may be difficult in patients with epiglottitis, an appropriately placed
endotracheal tube fully stabilizes most patients since the inflammation is
supraglottic with no tracheal or lower respiratory tract involvement. Rarely is
intubation necessary for more than 24 to 48 hours in these patients, after which
antibiotics have begun to reduce the swelling associated with infection. In a
patient with viral or bacterial tracheitis, however, intubation for more than 24 to
48 hours may produce tracheal injury and ulceration.

Tracheomalacia
Tracheomalacia, sometimes complicating lung disease of prematurity, is a
relatively common cause of airway obstruction. It is characterized by a floppy
trachea that collapses during expiration when the intrathoracic trachea is
compressed by the positive intrathoracic pressure. It can be caused by intrinsic
tracheal defects, extrinsic compression by surrounding structures, or from
prolonged positive pressure ventilation. It commonly occurs in association with
TEF repair (see TEF below).
Clinical Recognition
The clinical presentation of tracheomalacia depends on the severity and location

of obstruction with more severe lesions presenting earlier in infancy. When the
intrathoracic trachea is involved, patients often have expiratory wheeze that may
be hard to distinguish from asthma. Intrathoracic involvement is more likely to
cause stridor, which can progress to occur at rest. Patients often have cough and
evidence of respiratory distress. They may present with recurrent respiratory
infections and episodes of severe obstruction and respiratory failure.
Tracheomalacia is typically diagnosed using bronchoscopy during spontaneous
respiration, which demonstrates the characteristic tracheal collapse with
expiration. Although dynamic imaging studies may be useful, standard imaging
modalities are typically not helpful in making this diagnosis.
Management
In general, children who are otherwise healthy will have resolution of symptoms
by about 1 year of age as the cartilaginous tracheal structures mature. During
episodes of acute illness, however, these children can present with severe work of


breathing, cyanosis, and respiratory failure. In addition to medical management,
they may benefit from noninvasive or invasive ventilatory strategies. The subset
of children with severe disease resulting in recurrent bouts of respiratory failure
may require tracheal surgery or placement of a tracheal stent.

Vascular Rings
Vascular rings represent a rare and varied group of developmental anomalies of
the aorta and great vessels. They may produce obstruction of the esophagus,
trachea, or both. These rings are a result of failure of the normal involution of the
appropriate segments of the six embryologic aortic arches. Vascular rings are
characterized as complete when both the esophagus and trachea are fully
encircled and incomplete when they are only partially encircled. Complete rings
are typically caused by a double aortic arch or a right-sided aortic arch with an
aberrant left subclavian artery and left ductus arteriosus or ligamentum.

Incomplete rings are often caused by a pulmonary artery sling, innominate artery
compression, or an aberrant right subclavian artery. The level of respiratory
obstruction is usually the trachea, but compression of a bronchus by the ductus
arteriosus or by a pulmonary artery sling, may produce compression more
distally.
Clinical Recognition
Vascular rings may be asymptomatic in infancy but lead to significant airway
obstruction in childhood. The wide variety of anomalies produces varying
degrees of symptoms. Presentations range from incidental findings on imaging
studies to neonates with critical airways. Vascular rings should be suspected in
infants with stridor, dysphagia, failure to thrive associated with difficult feeding,
or recurrent pneumonia. Esophageal obstruction can produce difficulty
swallowing. A patient with esophageal compression may also have respiratory
symptoms from compression on the trachea from a distended esophageal pouch.
This may lead to reflex apnea during feeding, and eventually tracheomalacia in a
more chronic setting.
Often, diagnosis is delayed by failure to consider these anatomic obstructions
since their presentation can be quite varied and subtle. In a patient presenting with
an acute airway obstruction or other medical problems requiring intubation and
nasogastric tube placement, detection of a vascular ring can be even more
difficult because of the presence of these tubes. Chest radiographs are the initial
test of choice and suggestive findings include an abnormal-appearing aortic knob
or deviation of the trachea or esophagus. Chest radiographs may be supplemented
by various diagnostic tests: contrast esophagography (e.g., barium swallow),


angiography, echocardiography, magnetic resonance imaging (MRI), and digital
subtraction angiography are needed in some combination to define the anatomy.
Management
Although some patients with constricting anomalies improve as they grow, most

will require surgical correction. Surgical treatment is usually indicated to relieve
the obstruction, with predictable and immediate resolution of symptoms and
excellent outcomes. Surgical repair is accomplished by dividing the vascular ring
and preserving the blood supply to the aortic branches. This is usually
accomplished by a left thoracotomy but more recently, video-assisted
thoracoscopic surgery (VATS) and endoscopic robotic-assisted techniques have
been adopted in some centers for select patients.

BRONCHIAL LESIONS
Bronchial Atresia
Congenital bronchial atresia is a rare anomaly characterized by a bronchocele
caused by a mucus-filled, blindly terminating segmental or lobar bronchus, with
resulting hyperinflation of the distal obstructed segment of lung. Hyperaeration is
believed to result from communication with the normally aerated lung via the
pores of Kohn and the channels of Lambert.
Clinical Recognition
Neonates and infants with this lesion are usually seen for respiratory distress. In
older patients, a history of episodic upper respiratory infection and wheezing may
be elicited. Some older patients may complain of dyspnea on exertion or
unilateral chest pain. Physical examination findings seldom suggest the diagnosis,
but unilaterally decreased breath sounds may be evident.
Management
Often, the diagnosis is suggested by chest radiograph, but high-resolution chest
CT scan may be necessary to more closely define the anatomy. Bronchoscopy is
the most efficient way to identify the atretic opening to the involved bronchus.
Complete atresia of a main stem or lobar bronchus may lead to infectious
complications or compression symptoms from overdistention of the affected lobe.
This may require surgical management, such as lobectomy.

Primary Tracheobronchial Tumors