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.

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.