Written, informed consent
was given by all 100 consecutively enrolled women undergoing
elective plastic surgery or ear, nose, and throat
surgery (ENT) at the University Hospital in Orebro,
Sweden, from March to December 2008. Inclusion criteria
were women at least 18 years of age, ASA physical
status 1 or 2, elective surgery in the supine position with
expected duration longer than 90 minutes,