Affiliation: | L.P. Wang, Senior Registrar in Anaesthesia, C. Hermann, Registrar in Anaesthesia, Department of Anaesthesia. Hillerod Hospital, DK-3400 Hillerod, Denmark;P. Westrin, PhD, Senior Registrar in Anaesthesia, Department of Anesthesiology, Lund University Hospital, S-221 85 Lund, Sweden. |