[1] Kantonsspital Basel, Univ Hosp, Dept Anaesthesia, CH-4031 Basel, Switzerland
[2] Univ Hosp, Dept Anaesthesia, CH-1205 Geneva, Switzerland
[3] Kantonsspital Basel, Univ Womens Hosp, Dept Obstet & Gynecol, CH-4031 Basel, Switzerland
[4] Univ Hosp, Clin Pharmacol, CH-8000 Zurich, Switzerland