Avoiding iatrogenic adverse outcomes and providing safe care to patients is a priority in anaesthesia. The first step remains however to accurately measure such complications.Clinical indicators offer interesting perspectives as patient safety measurement tools.However, to date, only a few have been validated for such purpose. This book describes how an unplanned admission to the intensive care unit within 24hours of a procedure with an anaesthetist in attendance has been chosen and validated as a measure of patient safety in anaesthesia