title: Autocalibrating pulse contour analysis based on radial artery applanation tonometry for continuous non-invasive cardiac output monitoring in intensive care unit patients after major gastrointestinal surgery--a prospective method comparison study.
abstract: The T-Line(®) system (Tensys(®) Medical Inc., San Diego, CA, USA) non-invasively estimates cardiac output (CO) using autocalibrating pulse contour analysis of the radial artery applanation tonometry-derived arterial waveform. We compared T-Line CO measurements (TL-CO) with invasively obtained CO measurements using transpulmonary thermodilution (TDCO) and calibrated pulse contour analysis (PC-CO) in patients after major gastrointestinal surgery. We compared 1) TL-CO versus TD-CO and 2) TL-CO versus PC-CO in 27 patients treated in the intensive care unit (ICU) after major gastrointestinal surgery. For the assessment of TD-CO and PC-CO we used the PiCCO(®) system (Pulsion Medical Systems SE, Feldkirchen, Germany). Per patient, we compared two sets of TD-CO and 30 minutes of PC-CO measurements with the simultaneously recorded TL-CO values using Bland-Altman analysis. The mean of differences (± standard deviation; 95% limits of agreement) between TL-CO and TD-CO was -0.8 (±1.6; -4.0 to +2.3) l/minute with a percentage error of 45%. For TL-CO versus PC-CO, we observed a mean of differences of -0.4 (±1.5; -3.4 to +2.5) l/minute with a percentage error of 43%. In ICU patients after major gastrointestinal surgery, continuous non-invasive CO measurement based on autocalibrating pulse contour analysis of the radial artery applanation tonometry-derived arterial waveform (TL-CO) is feasible in a clinical study setting. However, the agreement of TL-CO with TD-CO and PC-CO observed in our study indicates that further improvements are needed before the technology can be recommended for clinical use in these patients.
authors.affiliation: Anaesthesiologist, Department of Anaesthesiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wagner
authors.affiliation: Research assistant, Department of Anaesthesiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Langemann
authors.affiliation: Statistician, Department of Medical Biometry and Epidemiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Schön
authors.affiliation: Professor and Head of the Department of Intensive Care Medicine, Centre of Anaesthesiology and Intensive Care Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kluge
authors.affiliation: Professor and Co-Chairman of the Department of Anaesthesiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: D A
authors.initials: DA
authors.lastname: Reuter
authors.affiliation: EDIC and Associate Professor, Department of Anaesthesiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Saugel
mesh_terms: D000368:Aged; D002138:Calibration; D002302:Cardiac Output / Q000502:physiology*; D013505:Digestive System Surgical Procedures / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D017534:Radial Artery / Q000502:physiology*; D013815:Thermodilution / Q000379:methods
keywords: T-Line; cardiac output; critical care; haemodynamic monitoring; pulse contour analysis; transpulmonary thermodilution