Delayed Sudden Respiratory Arrest After a High-energy Motorcycle Accident.

A 50-year-old man driving a motorcycle at 100 kph crashed at a curve on a racing course. On arrival, he had clear consciousness, and his vital signs showed mild hypertension and tachycardia. His chief complaint was general pain. The only physiological finding was a labile injury. Whole-body computed tomography only showed fluid collection at the left maxillary sinus. While waiting on the results of a blood examination in the emergency room (ER), monitoring triggered an alarm due to a reduction in the percutaneous oxygen saturation. When a nurse checked him, he lost consciousness and entered respiratory arrest, showing left conjugated deviation and a palpable radial artery. He underwent indwelling tracheal intubation with mechanical ventilation. On the second hospital day, he regained consciousness and respiration and was therefore extubated. Brain magnetic resonance imaging revealed cerebellar infarction due to occlusion of a right vertebral artery, probably due to traumatic dissection. He was ultimately discharged on foot. This is a rare case of sudden-onset coma with respiratory arrest in the ER after a traffic accident due to occlusion of the right vertebral artery despite a clear consciousness on arrival. Physicians should closely monitor high-energy traffic accident victims, even when the patient has a clear consciousness and only minor physiological findings.