2018, Vol. 1, Issue 2, Part A

Objective: In this study, we compared three different anaesthetic induction techniques to standard IV propofol inductions (control) in their effect on reducing redistribution hypothermia.

Methods: Elective, afebrile patients, age 18 to 57 years, were randomly assigned to one of four groups (n = 60 each). Group “PROP” was induced with 2.2 mg/kg propofol, Group “INH/100” with 8% sevoflurane in 100% oxygen, Group “INH/50” with 8% sevoflurane in 50% oxygen and 50% nitrous oxide, and Group “Phnl/PROP” with 2.2 mg/kg propofol immediately preceded by 160 mcg phenylephrine. Patients were maintained with sevoflurane in 50% nitrous oxide and 50% oxygen in addition to opioid narcotic. Forced air warming was used. Core temperatures were recorded every 15 min after induction for 1 h.

Results: Compared to control group PROP, the mean temperatures in groups INH/100, INH/50, and Phnl/PROP were higher 15, 30, 45 and 60 min after induction, averaging between 0.29 °C and 1.0 °C higher (p< 0.001 for all comparisons). There were statistically significant differences in the mean temperatures between groups INH/ 100 and INH/50, INH/100 and Phyl/PROP, and INH/50 and Phyl/PROP at any time point (all p< 0.05). Few patients in three groups had a core temperature >37.5 °C at T60 time point, except PROP group.

Conclusions: The inhalation inductions with sevoflurane or with prophylactic phenylephrine bolus prior to propofol induction reduced the magnitude of redistribution hypothermia by an average of 0.29 to 1.0 °C in patients aged 18 to 57 years.