Emergency and Toxicologymiddle twist
A 22-year-old man was struck on the right temple by a cricket ball three hours ago in a country town. He was briefly unconscious, then walked off the field and chatted normally; over the last hour he has become progressively drowsy and has vomited twice. At the local hospital, a computed tomography scan shows a large lens-shaped collection under the right temporal bone with 12 mm of midline shift. While waiting for the retrieval helicopter, his Glasgow Coma Scale falls from 13 to 8, and his right pupil becomes 6 mm and unreactive. He has been intubated and ventilated by the local anaesthetist.
Which one of the following is the most appropriate next step?