Novel combination techniques for anaesthetic induction to manage perioperative hypothermia: A prospective, randomized, controlled, single blind trial

Abstract

Background: Intraoperative hypothermia is common issue with serious consequences occurred during anaesthesia. However, less attention has been directed to preventing redistribution hypothermia there is need of effective techniques to develop. 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.