A 32-year-old male is admitted to the ICU following a severe motor vehicle accident. He has a Glasgow Coma Scale (GCS) score of 7. Initial CT scan shows a large subdural hematoma with midline shift. His vital signs are: BP 180/100 mmHg, HR 50 bpm, RR B breaths/min, SpO2 96% on mechanical ventilation. The nurse notes that his right pupil has suddenly become dilated and nonreactive. What is going on?