Tension Hemomediastinum Secondary to Blunt Chest Trauma in a Patient With an Anomalous Manubrial–Sternal Junction Jon Marinaro, MD, Sara Zwehl-Burke, MD, James McAnally, MD, Cameron Crandall, MD, and Gerald Demarest, MD J Trauma. 2009;66:1489 –1491. CASE REPORT A previously healthy 25-year-old man presented to our emergency department at 9 AM after being assaulted. He complained of severe chest pain from being kicked in the chest approximately 4 hours earlier. He noted that his chest pain was worse with coughing and that he felt sweaty. He denied other medical problems, and stated that his recent drug use included alcohol and marijuana. Review of systems was otherwise unremarkable. Initial vital signs revealed a blood pressure of 125/65, heart rate of 111 bpm, respiratory rate of 18, and an oxygen saturation of 98%. The patient was a thin man, alert and oriented, with no external signs of trauma. He had tenderness across his entire anterior chest wall without crepitus, bruising, deformity, or abnormal heart or lung sounds. The initial chest X-ray was initially interpreted (mistak- enly) as unremarkable (Fig. 1) and the patient’s pain im- proved with oral pain medication. Upon reevaluation and consideration for discharge, the patient was found to have a heart rate of 150 bpm. An intravenous line was placed and 2 L of saline were infused. A hematocrit, electrocardiogram, and urine drug screen were ordered. The patient then became hypoxic, requiring supplemen- tal oxygen. His sleeping oxygen saturation was 88%, and his heart rate ranged from 120 to 130 bpm despite the fluid boluses. The patient’s chest X-ray was repeated to evaluate for pneumothorax (Fig. 2). This revealed a significantly wid- ened mediastinum and an abnormal left heart border. A trans- thoracic echocardiogram and a computed tomography (CT) scan of the chest were performed. The echocardiogram was interpreted as abnormal. There was no pericardial effusion, but “an unidentified structure or fluid collection was seen to be impinging severely on the left atrium.” CT scan of the chest revealed a large anterior me- diastinal hematoma with active bleeding in its center (Fig. 3). The patient’s heart rate progressively increased to 178 bpm, and his blood pressure was 137/80. He was immediately taken to the operating room for a median sternotomy. Left-side tube thoracostomy placement resulted in approximately 2 L of hemothorax being evacuated from his chest cavity. The left internal thoracic artery was identified as the source of bleeding, and was successfully ligated. The patient was taken to the intensive care unit, where he had an uneventful recovery. DISCUSSION Several case reports have described mediastinal hemor- rhage secondary to blunt chest trauma. 1–5 The majority of these cases include a history of significant force to the body such as the deceleration inherent in motor vehicle collisions or falls from great heights. In addition these case reports were accompanied by sternal fractures and other signifi- cant injuries. Only in one report 6 was there a patient without a fracture, yet this patient did not show tension physiology. In our case report, we demonstrate that an echocardiographically confirmed tension hemomediasti- num may occur without fracture or significant mechanism. In addition, this patient had an anomalous manubrial–sternal joint which may have contributed to his morbidity, despite the low mechanism. Although the report of a human kick to the chest may seem less than sufficient to cause life-threatening trauma (with the exception of commotio cordis), estimates of the speed generated by a professional soccer player’s kick are approximately 70 mph. 7 Therefore, classifying a human kick to the chest as low mechanism is probably a general under- estimate of its potential force. However, in the case of this patient, the lack of bony abnormalities identified on plain radiographs makes it unlikely that the full potential of a human kick was imparted on the patient. Recently, Kehdy and Richardson 8 suggested that three- dimensional CT scan might facilitate more accurate and com- plete characterization of sternal fractures. With this in mind, Submitted for publication September 1, 2006. Accepted for publication November 8, 2006. Copyright © 2009 by Lippincott Williams & Wilkins From the Departments of Surgery (J. Marinaro, G.D.), Emergency Med- icine (J. Marinaro, S.Z.-B., C.C.), and Radiology (J. McAnally), University of New Mexico Hospital, Albuquerque, New Mexico. Address for reprints: Jon Marinaro, MD, Department of Surgery and Emergency Medicine, University of New Mexico Hospital, Albuquerque, NM; email: jmarinaro@salud.unm.edu. DOI: 10.1097/TA.0b013e31802e749d Case Report The Journal of TRAUMA  Injury, Infection, and Critical Care Volume 66 • Number 5 1489