Magnus A Garrioch, MB ChB (Birm), FRCA, FRCP (Glasg), consultant (attending) in anaesthesiology and critical care, Manchester Royal Infirmary, Central Manchester University Hospitals NHS Trust, England, UK. W Bosseau Murray, MB ChB (Pretoria), FRCA (Lon), MD (Stellenbosch), professor of anesthesiology, Department of Anesthesia, Pennsylvania State University, Hershey, USA.