title: Femoro-iliacal artery versus pulmonary artery core temperature measurement during therapeutic hypothermia: an observational study.
abstract: OBJECTIVE
  Therapeutic hypothermia after cardiac arrest improves neurologic outcome. The temperature measured in the pulmonary artery is considered to best reflect core temperature, yet is limited by invasiveness. Recently a femoro-arterial thermodilution catheter (PiCCO-Pulse Contour Cardiac Output) has been introduced in clinical practice as a safe and accurate haemodynamic monitoring system, which is also able to measure blood temperature. The aim of the study was to investigate, if the temperature measured with the PiCCO catheter reflects pulmonary artery temperature better than other sites during therapeutic hypothermia.
  
  
  METHODS
  In this observational study twenty patients after cardiac arrest and successful resuscitation were cooled with various cooling methods to 33 ± 1°C for 24h, followed by rewarming. Temperatures were recorded continuously in the pulmonary artery (Tpa), femoro-iliacal artery (Tpicco), ear canal (Tear), oesophagus (Toeso) and urinary bladder (Tbla). We assessed agreement of methods using the Bland Altman approach including bias and limits of agreement (LA).
  
  
  RESULTS
  All other sites differed significantly from Tpa with the bias varying from 0.4°C (Tbla) to -0.6°C (Tear). Standard deviations varied from 0.1°C (Tpicco, Toeso) to 0.5°C (Tear). For all sites bias was closer to zero with increasing average temperatures. Bias tended to be larger in the cooling phase compared to overall measurements.
  
  
  CONCLUSIONS
  Temperature measurement in the femoro-iliacal artery (Tpicco) reflects the gold standard of pulmonary artery temperature most accurately, especially during the cooling phase. Tpicco is easily accessible and might be used for monitoring core temperature without the need for additional temperature probes.
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Austria.
authors.forename: Danica
authors.initials: D
authors.lastname: Krizanac
authors.forename: Peter
authors.initials: P
authors.lastname: Stratil
authors.forename: David
authors.initials: D
authors.lastname: Hoerburger
authors.forename: Christoph
authors.initials: C
authors.lastname: Testori
authors.forename: Christian
authors.initials: C
authors.lastname: Wallmueller
authors.forename: Andreas
authors.initials: A
authors.lastname: Schober
authors.forename: Moritz
authors.initials: M
authors.lastname: Haugk
authors.forename: Maria
authors.initials: M
authors.lastname: Haller
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Behringer
authors.forename: Harald
authors.initials: H
authors.lastname: Herkner
authors.forename: Fritz
authors.initials: F
authors.lastname: Sterz
authors.forename: Michael
authors.initials: M
authors.lastname: Holzer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015982:Bias; D001831:Body Temperature / Q000502:physiology*; D002407:Catheterization, Swan-Ganz / Q000295:instrumentation*; D015331:Cohort Studies; D005260:Female; D005263:Femoral Artery / Q000502:physiology*; D006323:Heart Arrest / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D011651:Pulmonary Artery / Q000502:physiology*; D013815:Thermodilution / Q000295:instrumentation