Traumatic mediastinal hematoma: a potentially fatal condition that may be overlooked by traditional Focused Assessment with Sonography for Trauma.

Mediastinal hematoma is an uncommon finding in blunt chest trauma. It may be caused by aortic injury, by mediastinal vascular injury such as aortic injury, and by fractures of the sternum and vertebral column. A huge mediastinal hematoma can result in extrapericardial cardiac tamponade by compressing the adjacent organs. Although Focused Assessment with Sonography for Trauma (FAST) can reliably assess the presence of pericardial effusion in the subxiphoid view, it may overlook mediastinal hematoma. We present a 67-year-old male victim of blunt chest trauma complicated with expanding anterior mediastinal hematoma that was undetectable with standard FAST protocol. The large mediastinal hematoma can only be seen in the parasternal long-axis view. When ultrasound is used to assess for anteriorly located mediastinal hematoma, the transducer should be positioned in the parasternal or precordial area to scan into the pericardium and mediastinum. However, these 2 views (parasternal and precordial) are not included in emergency department's traditional FAST examination. The subxiphoid view of FAST can easily miss a mediastinal hematoma. For trauma patients with probable mediastinal injuries, we suggest doing an extended FAST with parasternal long-axis view. Alternatively, one should consider lowering the threshold of thoracic computed tomographic scan in patients with persistent symptoms because a missed mediastinal hematoma could be insidious and fatal.