title: Accuracy and precision of a novel non-invasive core thermometer.
abstract: BACKGROUND
  Accurate measurement of core temperature is a standard component of perioperative and intensive care patient management. However, core temperature measurements are difficult to obtain in awake patients. A new non-invasive thermometer has been developed, combining two sensors separated by a known thermal resistance ('double-sensor' thermometer). We thus evaluated the accuracy of the double-sensor thermometer compared with a distal oesophageal thermometer to determine if the double-sensor thermometer is a suitable substitute.
  
  
  METHODS
  In perioperative and intensive care patient populations (n=68 total), double-sensor measurements were compared with measurements from a distal oesophageal thermometer using Bland-Altman analysis and Lin's concordance correlation coefficient (CCC).
  
  
  RESULTS
  Overall, 1287 measurement pairs were obtained at 5 min intervals. Ninety-eight per cent of all double-sensor values were within +/-0.5 degrees C of oesophageal temperature. The mean bias between the methods was -0.08 degrees C; the limits of agreement were -0.66 degrees C to 0.50 degrees C. Sensitivity and specificity for detection of fever were 0.86 and 0.97, respectively. Sensitivity and specificity for detection of hypothermia were 0.77 and 0.93, respectively. Lin's CCC was 0.93.
  
  
  CONCLUSIONS
  The new double-sensor thermometer is sufficiently accurate to be considered an alternative to distal oesophageal core temperature measurement, and may be particularly useful in patients undergoing regional anaesthesia.
authors.affiliation: Department of Anesthesiology and General Intensive Care, Medical University of Vienna, Waehringer Gurtel 18-20, 1090 Vienna, Austria. study@kimberger.at
authors.forename: O
authors.initials: O
authors.lastname: Kimberger
authors.forename: R
authors.initials: R
authors.lastname: Thell
authors.forename: M
authors.initials: M
authors.lastname: Schuh
authors.forename: J
authors.initials: J
authors.lastname: Koch
authors.forename: D I
authors.initials: DI
authors.lastname: Sessler
authors.forename: A
authors.initials: A
authors.lastname: Kurz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature; D003422:Critical Care / Q000379:methods; D004867:Equipment Design; D004947:Esophagus / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D015203:Reproducibility of Results; D013821:Thermometers; D055815:Young Adult