July 02, 2016
Most serious torso injuries in children result from blunt trauma sustained in car, ATV or bicycle crashes. These injuries can be challenging to evaluate and treat due to children's unique anatomy. For instance, a child's chest wall can withstand more deformation than an adult's, so the force of an impact is transmitted widely through the body, often resulting in major internal injuries without any damage to the external chest wall. Rib fractures, which are rare in kids, are usually a sign of severe impact.
"You may not see rib fractures, but children can have pneumothoraces or pulmonary contusions that are profound," says Denise B. Klinkner, M.D., M.Ed., a pediatric surgeon at Mayo Clinic's campus in Rochester, Minnesota. "These patients may seem relatively stable at first but can deteriorate quickly, and contusions will often blossom over the first 24 hours. The possibility of internal chest injuries should always be kept in mind during the primary survey."
A pneumothorax — a collection of air in the area between the lung and chest wall that causes the lung to collapse — is an especially challenging diagnosis for children because their mediastinum isn't fixed. If the pressure in the pleural space becomes high enough, the mediastinum, which contains the heart, vena cava, trachea and aorta, can shift, decreasing cardiac function. Needle decompression followed by tube decompression or tube decompression alone is the main treatment and should be initiated before a patient is transferred.
Not all pneumothoraces can be seen on X-rays, however. In 2014, the results of a large, multicenter observational study of pediatric patients with blunt chest trauma were published in Academic Emergency Medicine. The study looked at 8,000 children evaluated in emergency departments in the Pediatric Emergency Care Applied Research Network from 2007 to 2010. Nearly 400 had pneumothoraces, more than half of which weren't visible on chest X-rays and only later discovered on CT.
The significance — and treatment — of small, occult pneumothoraces isn't always clear, and Dr. Klinkner says the need for CT should be decided at a higher level of care. "Both the Southern Minnesota Regional Trauma Advisory Committee and Mayo's practice management guidelines state that no additional imaging is needed if the initial X-ray is normal, although a repeat radiograph may be justified if the patient appears to be doing well and won't need to be transferred," she explains.
Pulmonary contusion (a bruise to the lung tissue itself) is the most common thoracic injury in kids. It causes the air sacs in the lung to fill with blood, potentially leading to hypoxia. The contused tissue is also stiffer than normal, which can make breathing even more difficult. The amount of respiratory distress a child experiences depends on how much lung tissue is affected.
Pulmonary contusions may not always show up on the initial X-ray, but they should be suspected in any child with rib fractures because extreme force is needed to break a child's pliable ribs. Low-volume trauma centers should consider transferring children with rib fractures or pulmonary contusions to a higher level of pediatric care because these patients may need endotracheal intubation or extracorporeal membrane oxygenation (ECMO) support while their lungs heal.
Children with tracheal and bronchial injuries or injury to the aorta should be transferred to a higher level of pediatric care. Kids with tracheal injuries present with respiratory distress and often a tension pneumothorax and are generally treated with prolonged intubation.
Injuries to the aorta usually result from rapid deceleration in a car crash or auto-pedestrian collision. Although relatively common in adults, these injuries are rare in young children but sometimes occur in older adolescents. X-rays may show a widened mediastinum, and some patients have diminished or absent pulses in their upper or lower extremities. These injuries are life-threatening, and patients need immediate transfer.
Ultimately, Dr. Klinkner says two important rules apply to pediatric torso injuries:
- Any child with torso trauma is likely to have other, life-threatening trauma, especially to the head and limbs.
- Children with airway problems should always be transferred to a higher level of care because intubation may become urgently necessary to manage them safely.
For more information
Lee LK, et al. Occult pneumothoraces in children with blunt torso trauma. Academic Emergency Medicine. 2014;21:440.
Initial Management of Major Pediatric Trauma Patients. Southern Minnesota Regional Trauma Advisory Committee (SMRTAC).