From the Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3/R3, D-24105 Kiel, Germany (KW, SB, NK, JH, MS, AF) and the Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3/B1, D-24105 Kiel, Germany (PA)

Correspondence to Kerstin Wagener, Dr med., Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, R3, D-24105 Kiel, Germany. Tel: +49 431 50020801; fax: +49 431 50020804; e-mail: [email protected]