title: Radial artery applanation tonometry for continuous non-invasive arterial pressure monitoring in intensive care unit patients: comparison with invasively assessed radial arterial pressure.
abstract: BACKGROUND
  Radial artery applanation tonometry technology can be used for continuous non-invasive measurement of arterial pressure (AP). The purpose of this study was to evaluate this AP monitoring technology in intensive care unit (ICU) patients in comparison with invasive AP monitoring using a radial arterial catheter.
  
  
  METHODS
  In 24 ICU patients (German university hospital), AP values were simultaneously recorded on a beat-to-beat basis using radial artery applanation tonometry (T-Line system; Tensys Medical, San Diego, CA, USA) and a radial arterial catheter (contralateral arm). The primary endpoint of the study was to investigate the accuracy and precision of the non-invasively assessed AP measurements with the Bland-Altman method based on averaged 10 beat AP epochs (n=2993 10 beat epochs).
  
  
  RESULTS
  For mean AP (MAP), systolic AP (SAP), and diastolic AP (DAP), we observed a bias (±standard deviation of the bias; 95% limits of agreement; percentage error) of +2 mm Hg (±6; -11 to +15 mm Hg; 15%), -3 mm Hg (±15; -33 to +27 mm Hg; 23%), and +5 mm Hg (±7; -9 to +19 mm Hg; 22%), respectively.
  
  
  CONCLUSIONS
  In ICU patients, MAP and DAP measurements obtained using radial artery applanation tonometry show clinically acceptable agreement with invasive AP determination with a radial arterial catheter. While the radial artery applanation tonometry technology also allows SAP measurements with high accuracy, its precision for SAP measurements needs to be further improved.
authors.affiliation: II. Medizinische Klinik und Poliklinik.
authors.forename: A S
authors.initials: AS
authors.lastname: Meidert
authors.forename: W
authors.initials: W
authors.lastname: Huber
authors.forename: J N
authors.initials: JN
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Schöfthaler
authors.forename: A
authors.initials: A
authors.lastname: Hapfelmeier
authors.forename: N
authors.initials: N
authors.lastname: Langwieser
authors.forename: J Y
authors.initials: JY
authors.lastname: Wagner
authors.forename: F
authors.initials: F
authors.lastname: Eyer
authors.forename: R M
authors.initials: RM
authors.lastname: Schmid
authors.forename: B
authors.initials: B
authors.lastname: Saugel
mesh_terms: D000328:Adult; D000368:Aged; D062186:Arterial Pressure / Q000502:physiology*; D003422:Critical Care / Q000379:methods*; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D017534:Radial Artery / Q000502:physiology*; D015203:Reproducibility of Results
keywords: T-Line; arterial pressure, measurement; measurement techniques, arterial pressure; monitoring, intensive care