1. Dept of Anaesthesia and Intensive Care, John Hunter Hospital, Newcastle, N.S.W.
2. Intensive Care Unit, Austin and Repatriation Medical Centre, Heidelberg, Vic.
3. Department of Anaesthesia and Intensive Care, Austin and Repatriation Medical Centre, Heidelberg, Vic.
4. Department of Anaesthesia and Intensive Care, University of Adelaide and Royal Adelaide Hospital, Adelaide, S.A.