A Comparison of Inhalation vs. Intravenous Induction

Hypothermia occurs with anesthetic induction due to redistribution hypothermia. Hypothermia
has adverse effects and should be avoided or minimized. Intravenous propofol induction is
the most common technique used for anesthetic induction. There is preliminary evidence that
there is less redistribution hypothermia when anesthetic induction is achieved by inhalation
induction compared to intravenous induction. There is not enough data to compel a change in
practice patterns. This study will enroll a larger number of patients in order to provide
stronger evidence that there is a significant difference between induction techniques on
body temperature. Patients will be randomly assigned to two variation of inhalation
induction techniques and two variations of intravenous induction. The effect on temperature
between the four groups will be compared. Reducing the degree of hypothermia has the
potential to decrease surgical infection rate as well as providing other benefits to
patients.

Inclusion Criteria:

Elective surgery Adult, age >= 18 years old Scheduled for general anesthesia Medically fit
and able to safely go any of the four anesthetic inductions in the study

Exclusion Criteria:

Emergency surgery, or any other aspiration risk Minor, age <18 Pregnant Febrile illness
Contraindication to nasal instrumentation Allergy to propofol Malignant hyperthermia
Requiring Total Invravenous Anesthesia (TIVA) Inability to oxygenate on less than 50% FiO2
Intra-cranial surgery Receiving vasoactive medications Significant valvular heart disease
Unstable cardiac disease Surgery requiring prone or lateral positioning Contraindication
to nitrous oxide Prisoners