title: Comparison of the efficacy of a forced-air warming system and circulating-water mattress on core temperature and post-anesthesia shivering in elderly patients undergoing total knee arthroplasty under spinal anesthesia.
abstract: BACKGROUND
  In the present study, we compared changes in body temperature and the occurrence of shivering in elderly patients undergoing total knee arthroplasty under spinal anesthesia during warming with either a forced-air warming system or a circulating-water mattress.
  
  
  METHODS
  Forty-six patients were randomly assigned to either the forced-air warming system (N = 23) or circulating-water mattress (N = 23) group. Core temperature was recorded using measurements at the tympanic membrane and rectum. In addition, the incidence and intensity of post-anesthesia shivering and verbal analogue score for thermal comfort were simultaneously assessed.
  
  
  RESULTS
  Core temperature outcomes did not differ between the groups. The incidence (13.0 vs 43.5%, P < 0.05) and intensity (20/2/1/0/0 vs 13/5/3/2/0, P < 0.05) of post-anesthesia shivering was significantly lower in the forced-air system group than in the circulating-water mattress group.
  
  
  CONCLUSIONS
  The circulating-water mattress was as effective as the forced-air warming system for maintaining body temperature. However, the forced-air warming system was superior to the circulating-water mattress in reducing the incidence of post-anesthesia shivering.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Kyu Chang
authors.initials: KC
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Myeong Jong
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Mi-Na
authors.initials: MN
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Ji-Sub
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Won Sang
authors.initials: WS
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Chungju Hospital, Konkuk University Medical School, Chungju, Korea.
authors.forename: Jung Hwa
authors.initials: JH
authors.lastname: Lee
keywords: Shivering; Spinal anesthesia; Temperature