1. Department of Anaesthesia, Sir Charles Gairdner Hospital, Sir Charles Gairdner Hospital, Nedlands, Australia
2. Department of Anaesthesia, Royal Brisbane and Women’s Hospital, Brisbane, Australia
3. Department of Anaesthesia, Royal Adelaide Hospital and Women and Children’s Hospital, Adelaide, Australia
4. Department of Anaesthesiology, Auckland City Hospital, Auckland, New Zealand
5. University of Auckland, Auckland, New Zealand This article is a copy of a report submitted to the Australian and New Zealand Tripartite Anaesthesia Data Committee (ANZTADC). It is published on behalf of ANZTADC at their request and with their permission. It has not been subject to peer review.