title: Non-invasive continuous arterial pressure measurement based on radial artery tonometry in the intensive care unit: a method comparison study using the T-Line TL-200pro device.
abstract: BACKGROUND
  The T-Line TL-200pro (TL-200pro) device (Tensys Medical, Inc., San Diego, CA, USA), based on radial artery tonometry, provides an arterial pressure (AP) waveform and beat-to-beat values of systolic arterial pressure (SAP), mean arterial pressure (MAP), and diastolic arterial pressure (DAP). The aim of the study was to evaluate this non-invasive technique for continuous AP monitoring in medical intensive care unit (ICU) patients.
  
  
  METHODS
  Arterial pressure measurements obtained using the TL-200pro technology were compared using Bland-Altman analysis with values measured directly from a femoral arterial catheter in 34 ICU patients.
  
  
  RESULTS
  Arterial pressure values were analysed and compared in 4502 averaged 10-beat epochs. A bias of +0.72 mm Hg (95% limits of agreement -9.37 to +10.82 mm Hg) was observed for MAP. For SAP and DAP, there was a mean difference of -1.39 mm Hg (95% limits of agreement -18.74 to +15.96 mm Hg) and +4.36 mm Hg (95% limits of agreement -8.66 to +17.38 mm Hg), respectively. The percentage error for MAP, SAP, and DAP was 12%, 14%, and 21%, respectively.
  
  
  CONCLUSIONS
  Arterial pressure measurement based on radial artery tonometry using the TL-200pro technology is feasible in medical ICU patients. The TL-200pro system is capable of providing MAP values with high accuracy (low mean difference) and precision (narrow limits of agreement) compared with MAP measured invasively using a femoral arterial catheter. The TL-200pro technology is promising for the measurement of SAP and DAP but further development is necessary to improve accuracy and precision.
authors.affiliation: II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Strasse 22, D-81675 München, Germany. bernd.saugel@gmx.de
authors.forename: B
authors.initials: B
authors.lastname: Saugel
authors.forename: A S
authors.initials: AS
authors.lastname: Meidert
authors.forename: A
authors.initials: A
authors.lastname: Hapfelmeier
authors.forename: F
authors.initials: F
authors.lastname: Eyer
authors.forename: R M
authors.initials: RM
authors.lastname: Schmid
authors.forename: W
authors.initials: W
authors.lastname: Huber
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D001795:Blood Pressure Determination / Q000295:instrumentation* / Q000379:methods; D015924:Blood Pressure Monitors; D003422:Critical Care / Q000379:methods*; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D017534:Radial Artery / Q000502:physiology*
keywords: arterial pressure, measurement; measurement techniques, arterial pressure; monitoring, intensive care