Pediatric emergency medicine trisk 1025

with low morbidity and mortality; thoracoscopic resection is feasible for some
lesions, with the remainder approached via traditional thoracotomy.

Bronchogenic Cyst
Bronchogenic cysts are believed to result from aberrant budding from the
primitive foregut or tracheobronchial tree. They arise from the trachea or a
bronchus and may be found anywhere along the tracheobroncheal tree, in the lung
substance, adjacent to the esophagus or in other ectopic locations.
Clinical Recognition
Centrally located cysts may present with symptoms caused by compression of an
airway or the esophagus. Wheezing, persistent cough, fever, recurrent pneumonia,
and dysphagia may result in such children. In infants and smaller children, large
airway compression can lead to significant and life-threatening air trapping and
CLE. In contrast, patients with peripherally located cysts are more likely to be
asymptomatic or present with milder, nonspecific symptoms, such as cough,
dyspnea, tachypnea, or wheezing. Physical examination is often unrevealing, but
in patients with large, centrally located lesions, tracheal deviation may be present.
Management
Initial detection of bronchogenic cysts almost always occurs by radiograph. Chest
radiograph may demonstrate findings of a smooth paratracheal or hilar mass,
airway displacement and/or air trapping, or a structure containing an air–fluid
level if there is communication with the airway or gastrointestinal tract (Fig.
124.8 ). CT scan and MRI are helpful in identifying and delineating the anatomic
relations of these lesions to surrounding structures. Cysts with turbid, mucoid
fluid may appear solid on CT scan.
The standard treatment of bronchogenic cysts is surgical resection, even if
asymptomatic. Active infection, if present, should be brought under control
before resection. Typically, this is done in the inpatient setting with intravenous
antibiotics and close observation. Asymptomatic cysts should be removed to
establish the diagnosis and to prevent the complications of secondary bronchial
communication, bleeding, or perforation into the pleural cavity. Carcinomas and

fibrosarcomas have been reported to arise in benign-appearing bronchogenic
cysts. Preservation of adjacent normal lung parenchyma is ideal, but some lesions
require concomitant wedge, segmental, or lobar lung resection. Thoracoscopy
may be used for some lesions, depending on their location and size.


FIGURE 124.8 A: Plain film of a patient with a bronchogenic cyst arising from the right main
stem bronchus. B: Computed tomographic scan of a similar lesion reveals large fluid-filled cyst
compressing adjacent lung tissue.


Congenital Lobar Emphysema
Congenital lobar emphysema (CLE), also known as congenital lobar
hyperinflation (CLH), is caused by overexpansion of the air spaces of a segment
or lobe of histologically normal lung (Fig. 124.9 ). Operative findings can reveal
large blebs protruding from the lung parenchyma (Fig. 124.10 ), but often the
lobe is anatomically normal in appearance, with the exception of massive
overdistention. Compression of adjacent normal lung and mediastinal structures
frequently occurs, which can result in impairment of gas exchange and lifethreatening circulatory collapse. This process is caused by air trapping from either
a developmental deficiency of supporting cartilage in the bronchus of a particular
lobe or a partially obstructing bronchial lesion, either endobronchial or from
external compression (as with a bronchogenic cyst).

FIGURE 124.9 Congenital lobar emphysema of the left upper lobe in a 3-month-old girl who
presented with decreased breath sounds and rales in this area. Note the left-sided secondary
compression atelectasis of the lower lobe.

Clinical Recognition

Infants with CLE are often normal in appearance at birth, but develop tachypnea,
cough, wheezing, dyspnea, and/or cyanosis within a few days. The onset of
symptoms may be more gradual; nevertheless, 80% of patients are symptomatic
by 6 months of age. The upper lobes are involved in about two-thirds of patients.
Chest radiographs show striking radiolucency in the involved lobe with
mediastinal shift to the opposite side. The diaphragm is usually flattened on the
affected side. It can be difficult to tell whether pulmonary markings are present in
the involved lobe, and pneumothorax may be suspected. The compressed normal
lung may be erroneously believed to be atelectatic with the emphysematous lobe
compensatory.
Management
Initially, the clinical presentation and physiologic derangements may be similar to
that of tension pneumothorax, and the two entities should be distinguished.
Physical examination may reveal an asymmetric thorax, unilateral
hyperresonance and decreased breath sounds on the affected side, and evidence of
mediastinal shift. Typical findings on chest radiograph include lobar
overinflation, contralateral shift of the mediastinum, and collapse of lung tissue
on the contralateral side, with flattening of the ipsilateral hemidiaphragm ( Fig.
124.9 ). In a stable patient, CT or ventilation/perfusion scanning can be helpful in
establishing the diagnosis.

FIGURE 124.10 Operative findings in a child with congenital lobar emphysema.