M J Barrington1, B D Sites2. 1. Department of Anaesthesia and Acute Pain Medicine, St. Vincent's Hospital, Melbourne, Victoria Parade, PO Box 2900, Fitzroy, VIC 3065, Australia michael.barrington@svha.org.au. 2. Department of Anesthesiology and Pain Management, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756, USA.