Trauma, Hemothorax

The patient described in the vignette has a right hemothorax, a collection of blood in the pleural space due to trauma. Physical findings of an acute hemothorax include respiratory distress, shock due to blood loss, and diminished breath sounds with dullness to percussion on the affected side. A thoracostomy tube should be inserted to evacuate the hematoma in any patient who has a radiologically significant hemothorax. Evacuation of the blood both reduces the risk for a clotted hemothorax and eventual restrictive lung disease and provides a method for evaluation of continuing blood loss. If the patient is in respiratory or circulatory distress and other physical findings suggest a hemothorax, tube thoracostomy should be  performed before a chest radiograph is obtained.

Continued bleeding at greater than 1 to 2 mL/kg per hour after chest tube placement is an indication for emergent operative thoracotomy, as is retained blood within the pleural cavity or an inability to re-expand the lung. There is no indication in the patient in the vignette for a diuretic such as furosemide. Endotracheal intubation should be considered for those in severe respiratory distress despite chest decompression with a chest tube. Elevation of the head of the bed is not advisable in a patient who has suffered significant acute blood loss.

Tube thoracostomy in a child is performed as in an adult at the 5th intercostal space anterior to the midaxillary line. The tube is tunneled into the thoracic cavity over the rib above the skin insertion site to avoid damage to the intercostal vessels. Blood within the pleural space may tamponade a bleeding source, so a hemothorax should be evacuated slowly to accommodate potential new bleeding. O-negative blood should be available for emergency transfusion if type-specific blood is not available. Blood from the hemothorax may be collected in a system that allows for autotransfusion.

The primary cause of hemothorax in children is laceration of the lung or of an intercostal artery following blunt trauma. Penetrating trauma is a less common cause, particularly among children. The pliability of a child's chest wall causes much of the force in blunt trauma to be transmitted to the lung, often resulting in damage to the pulmonary parenchyma, even in the absence of rib fractures. The force required to fracture a child's rib is significantly higher than that required for an adult. If rib fractures are present in a child, injury to underlying organs, such as liver, spleen, and lungs, should be suspected.

"Flail chest" refers to a discontinuity in a section of the thoracic cage following fractures in two or more ribs on the same side. This condition is uncommon in children because rib fractures are rare. The chest wall instability leads to paradoxic motion of the involved section during inspiration and expiration. Most patients who have a flail chest require positive- ressure ventilation via an endotracheal tube to re-expand the lung and splint the injured section.

References:
American College of Surgeons Committee on Trauma. Pediatric trauma.
In: Advanced Trauma Life Support for Doctors: Student Course Manual.
6th ed. Chicago, Ill: American College of Surgeons; 1997:289-311
American Heart Association, American Academy of Pediatrics. Trauma
resuscitation. In: Chameides L, Hazinski MF, eds. Pediatric Advanced
Life Support. Dallas, Tex: American Heart Association; 1997:8-1–8-9
Kadish H. Thoracic trauma. In: Fleisher GR, Ludwig S, eds. Textbook of
Pediatric Emergency Medicine. 4th ed. Philadelphia, Pa: Lippincott
Williams & Wilkins; 2000:1351-1352