Your Christmas Day came to a blurry end with quantities of port wine and Stilton cheese. You don't really remember going to bed, but soon afterwards you are aware that you have become a junior doctor working in an intensive care unit, trying to put in a central line. A sharp American voice from behind you snaps, “Doctor, your patient appears to be septicaemic. Are you aware that 20 000 US citizens die every year from catheter-related bloodstream infections?” In your panic, your hand jerks and the line flies out. Blood spurts over you, your patient, and the attending physician.

You wake up, dry mouthed and sweating. After groping for a couple of indigestion tablets you turn over and hope for better dreams. But now you are in front of a large audience in the Massachusetts General …