Tension Hemomediastinum Secondary to Blunt Chest Trauma in a Patient With an Anomalous Manubrial–Sternal Junction

Abstract

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 (mistakenly) as unremarkable (Fig. 1) and the patient’s pain improved 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 supplemental 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 widened mediastinum and an abnormal left heart border. A transthoracic 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 mediastinal 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.