1. Department of Anaesthesiology/Intensive Care, Danderyd Hospital, S-182 88 Stockholm, Sweden
2. Gastrocentrum, Department of Surgery, Centre for Surgical Sciences, Karolinska Institutet, Karolinska University Hospital at Huddinge, S-141 86 Stockholm, Sweden
3. Department of Anaesthesiology/Intensive Care, Centre for Surgical Sciences, Karolinska Institutet, Karolinska University Hospital at Huddinge, S-141 86 Stockholm, Sweden
4. Department of Animal Sciences, University of Illinois, Urbana, IL 61801, U.S.A.