Pediatric emergency medicine trisk 3704 3704

Pulmonary contusion is the most common intrathoracic injury in
children.
While many contusions cause only mild symptoms such as chest pain,
more severe injuries can lead to hypoxemia and respiratory failure.
Pulmonary contusions may not show up on CXR for 4 to 6 hours after
the injury, and in some cases may never be identified on plain films.
Given the force necessary to cause a pulmonary contusion, a high
index of suspicion for other associated injuries is required.

Current Evidence
Pulmonary contusion is the most common thoracic injury in children. Pulmonary
contusion occurs when a blunt force is applied to the lung parenchyma, though
the injury can also be seen in penetrating trauma. The pediatric thoracic cage
provides less protection from blunt force impact compared to adults, secondary to
greater cartilage content and the greater elasticity of the bones. Therefore,
external kinetic energy applied to the thorax is transferred more readily through
the chest wall to the underlying organs. Thus, a pediatric patient is more likely
than an adult to have an internal injury such as a lung contusion without external
evidence of trauma (e.g., rib fracture, laceration, bruising).
As in any contusion or bruise, the capillary network becomes damaged, leaking
fluid into the surrounding tissues. A ventilation:perfusion mismatch will occur
because of the extravasation of fluid into injured lung parenchyma, interfering
with oxygenation. As the edema and swelling worsen, the patient’s respiratory
status will deteriorate if the contusion is large.

Clinical Considerations
Clinical Recognition
Pulmonary contusion should be suspected in any child with blunt thoracic trauma
who presents with chest pain, difficulty breathing, or unexplained hypoxia. The
contusion may be visualized on radiography or inferred from the absence of
another explanation for these symptoms (such as pneumothorax). Due to the

pliable nature of the pediatric chest wall, pulmonary contusions can often be seen
in the absence of rib fracture. When present, however, rib fractures as well as
chest wall ecchymosis should further raise suspicion for underlying parenchymal
injury.
Triage