title: A randomized comparison of intraoperative PerfecTemp and forced-air warming during open abdominal surgery.
abstract: BACKGROUND
  The PerfecTemp is an underbody resistive warming system that combines servocontrolled underbody warming with viscoelastic foam pressure relief. Clinical efficacy of the system has yet to be formally evaluated. We therefore tested the hypothesis that intraoperative distal esophageal (core) temperatures with the PerfecTemp (underbody resistive) warming system are noninferior to upper-body forced-air warming in patients undergoing major open abdominal surgery under general anesthesia.
  
  
  METHODS
  Adults scheduled for elective major open abdominal surgery (liver, pancreas, gynecological, and colorectal surgery) under general anesthesia were enrolled at 2 centers. Patients were randomly assigned to underbody resistive or forced-air warming. Resistive heating started when patients were transferred to the operating room table; forced-air warming started after patients were draped. The primary outcome was noninferiority of intraoperative time-weighted average core temperature, adjusted for baseline characteristics and using a buffer of 0.5°C.
  
  
  RESULTS
  Thirty-six patients were randomly assigned to underbody resistive heating and 34 to forced-air warming. Baseline and surgical characteristics were generally similar. We had sufficient evidence (P=0.018) to conclude that underbody resistive warming is not worse than (i.e., noninferior to) upper-body forced-air warming in the time-weighted average intraoperative temperature, with a mean difference of -0.12°C [95% confidence interval (CI) -0.37 to 0.14]. Core temperatures at the end of surgery averaged 36.3°C [95% CI 36 to 36.5] in the resistive warming patients and 36.6°C [95% CI 36.4 to 36.8] in those assigned to forced-air warming for a mean difference of -0.34°C [95% CI -0.69 to 0.01].
  
  
  CONCLUSIONS
  Mean intraoperative time-weighted average core temperatures were no different, and significantly noninferior, with underbody resistive heating in comparison with upper-body forced-air warming. Underbody resistive heating may be an alternative to forced-air warming.
authors.affiliation: Department of Outcomes Research, Cleveland Clinic, 9500 Euclid Avenue/P77, Cleveland, OH 44195, USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Egan
authors.forename: Ethan
authors.initials: E
authors.lastname: Bernstein
authors.forename: Desigen
authors.initials: D
authors.lastname: Reddy
authors.forename: Madi
authors.initials: M
authors.lastname: Ali
authors.forename: James
authors.initials: J
authors.lastname: Paul
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Yang
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D060666:Airway Extubation; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D001831:Body Temperature; D004947:Esophagus / Q000502:physiology; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000517:prevention & control; D007430:Intraoperative Care / Q000295:instrumentation*; D007431:Intraoperative Complications / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011229:Preanesthetic Medication; D017694:Rewarming / Q000295:instrumentation*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous