Abstract
The case involves a male in his 20s, who was hit by a truck while he was riding his bicycle along a major road. A nearby hospital diagnosed multiple traffic accident injuries along with a pelvic fracture ; the patient was immediately transferred to our hospital. His consciousness level was 30 on the Japan Coma Scale (JCS) and 13 on the Glasgow Coma Scale (GCS). On examination, the patient was found to have multiple injuries including an acute subdural hematoma, a pulmonary contusion and a pelvic fracture. Since free air was observed in the abdominal cavity on CT, it was surgically dealt with orthopedic surgery for his pelvic fracture and his left thighbone fracture. The patient was found to have a retroperitoneal hematoma and hematoma in his ascending colon, but no obvious gastrointestinal perforation nor abdominal organ injury. Therefore nonsurgical pneumoperitoneaum was diagnosed and the abdominal wall was closed. As for the pathogenic mechanism explaining the presence of free air, it is possible that a pulmonary contusion caused pneumomediastinum to leak air into the abdominal cavity. A literature review was also performed.
