1. Clinic for Anaesthesiology, University of Erlangen‐Nürnberg, Krankenhausstr. 12, D‐91054, Erlangen, Germany
2. Department of Anaesthesiology, The National Hospital, 0027 Oslo, Norway
3. 3 Department of Anaesthesia, University of Bristol, Bristol Royal Infirmary, Bristol BS2 8HW, UK
4. 4 Department of Anaesthesia, Frenchay Hospital, Bristol BS16 1LE, UK
5. Department of Anaesthesia, Hôpital Ambroise Paré, 9 Avenue Charles de Gaulle, 92104 Boulogne, France
6. Department of Anaesthesia, National University Hospital, Copenhagen, Denmark
7. 7 Department of Anaesthesia, Hvidovre Hospital, Denmark
8. 8 Department of Anaesthesia, Central Hospital, S‐351 85 Växjö, Sweden
9. 9 Glaxo Wellcome Research & Development Limited, Greenford Road, Greenford, Middlesex, UB6 0HE, UK