Pediatric emergency medicine trisk 1017

displacement of the point of maximal impulse; shift or alteration in the heart
tones; or new murmurs, gallops, or friction rubs.

Evaluation
The most important study when evaluating any patient with a thoracic emergency
is a high-quality chest radiograph. The radiographs of the chest in the
posteroanterior (PA) and lateral views should be performed in an upright position
(unless contraindicated by the patient’s condition). The width of the mediastinum
and the degree of mediastinal shift are much better seen in the upright chest
radiograph. Moreover, abnormalities in the lung, pleural cavity, and diaphragm
are also best appreciated in this view. When a pulmonary effusion exists, lateral
decubitus anteroposterior views of the chest or an ultrasound can be obtained to
determine whether the effusion layers freely or is loculated.
In interpreting the chest radiograph, the clinician should distinguish between a
diffuse pulmonary problem and a focal lesion. Hyperaeration of one portion of
the lung suggests air trapping in the involved lobe. Hyperaeration of the entire
lung field on one side is usually the result of compensatory enlargement of the
lung because of atelectasis and loss of lung volume on the opposite side.
Depending on the condition, laboratory studies and advanced imaging modalities
may be indicated.

AIRWAY COMPROMISE
Airway compromise can occur anywhere in the respiratory tract from the nose to
the alveolus. Obstructive emergencies relating to the oropharynx, larynx, and
proximal trachea are discussed in Chapters 106 ENT Trauma and 118 ENT
Emergencies . Compromise of the more distal tracheobronchial tree may be
caused by lesions in the lumen, in the wall, or external to the bronchus. Intrinsic
bronchial obstructions may result from narrowing of the lumen by a tumor (e.g.,
carcinoid tumor), foreign body, or a mucous plug. Obstruction from lesions in the
wall of the bronchus includes collapse from tracheomalacia and stenosis after
tracheostomy. Extrinsic lesions (e.g., bronchogenic cyst or inflamed lymph

nodes) become symptomatic when the compression impinges on a bronchus.
Table 124.1 lists intraluminal, mural, and extrinsic conditions that produce airway
obstruction.
The anatomic level of the obstruction correlates with its effects: An obstruction
of the distal tracheobronchial tree may lead to segmental lung overdistention or
segmental infection. An obstruction of the proximal trachea affects both lungs,
with a much greater likelihood of catastrophe for the patient. Similarly, greater
degrees of obstruction, as a rule, lead to greater effects on gas exchange and


severity. Infection commonly follows obstruction of bronchial drainage because
the clearance of bacteria or inhaled foreign materials by the mucociliary elevator
is prevented.
TABLE 124.1
TRACHEOBRONCHIAL CONDITIONS ASSOCIATED WITH AIRWAY
COMPROMISE
Intraluminal
Foreign bodies
Aspiration (esophageal reflux, tracheoesophageal fistula, bronchial fistula,
biliary fistula, or esophageal fistula)
Mucous plugs (cystic fibrosis)
Granuloma (chronic intubation, tuberculosis)
Hemoptysis (vascular malformations, cystic fibrosis, tuberculosis, sarcoidosis,
hemosiderosis, lupus)
Acute infection (tracheitis)
Mural
Tracheomalacia
Lobar emphysema
Bronchial atresia
Bronchial tumors

Extrinsic
Lymphadenopathy
Bronchogenic cyst
Cystic hygroma
Esophageal duplication
Mediastinal tumors

Tracheal Obstruction
CLINICAL PEARLS AND PITFALLS


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.


FIGURE 124.1 Acute and chronic obstruction of a bronchus owing to tumor or cyst (T) or
lymph nodes (L). When the obstruction is acute, there may be bronchiectasis caused by
recurrent pneumonia. The right middle lobe as shown here is particularly prone to bronchial
obstruction caused by pressure from encircling lymph nodes. RUL, right upper lobe; RML,
right middle lobe; RLL, right lower lobe.

Goals of Treatment