title: Maintenance of body temperature in elderly patients who have joint replacement surgery. A comparison between the heat and moisture exchanger and heated humidifier.
abstract: The effect of a heat and moisture exchanger on intra-operative aural canal (core) and mean skin temperatures was investigated in elderly patients who had elective total hip arthroplasty under general anaesthesia with artificial ventilation of the lungs. Group 1 (n = 20) did not receive any form of artificial humidification while in group 2 (n = 20) a heat and moisture exchanger was inserted in the breathing system and in group 3 (n = 20) the inspired gases were humidified and warmed at 40 degrees C by means of a heated humidifier. Time of surgery, intravenous fluid administration and operating theatre temperature were standardised. Mean (SD) aural canal (core) temperature decreased significantly in groups 1 and 2 (p less than 0.001), while there was a fall of 0.3 degrees C (0.6) in group 3, which was not significant. Mean skin temperature decreased during anaesthesia and surgery in both groups 1 and 2 (p less than 0.05), while it increased in group 3. There was a significantly greater loss of body heat in groups 1 and 2 compared with group 3 intra-operatively (p less than 0.001). We conclude tha a heat and moisture exchanger did not prevent the decrease in intra-operative body temperature in elderly patients.
authors.affiliation: Department of Anaesthesia, Northwick Park Hospital and Clinical Research Centre, Harrow, Middlesex.
authors.forename: P C
authors.initials: PC
authors.lastname: Yam
authors.forename: F
authors.initials: F
authors.lastname: Carli
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D001831:Body Temperature / Q000502:physiology*; D006622:Hip Prosthesis; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D007430:Intraoperative Care / Q000379:methods*; D012121:Respiration, Artificial; D012881:Skin Temperature / Q000502:physiology