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Flick M, Bergholz A, Kouz K, Breitfeld P, Nitzschke R, Flotzinger D, Saugel B: A new noninvasive finger sensor (NICCI system) for continuous blood pressure and pulse pressure variation monitoring: A method comparison study in patients having neurosurgery. Eur J Anaesthesiol 2022; 39: 851-857

May 28, 2022

BACKGROUND The NICCI system (Getinge, Gothenburg, Sweden) is a new noninvasive haemodynamic monitoring system using a finger sensor.
OBJECTIVE(S) We aimed to investigate the performance of the NICCI system to measure blood pressure and pulse pressure variation compared with intra-arterial measurements.
DESIGN A prospective method comparison study.
SETTING University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
PATIENTS Forty-seven neurosurgery patients.
MAIN OUTCOME MEASURES We performed a method comparison study in 47 neurosurgery patients to compare NICCI blood pressure measurements (BP NICCI) with intra- arterial blood pressure measurements (BP ART ) (Bland–Alt- man analysis, four-quadrant plot, error grid analysis) and NICCI pulse pressure variation measurements (PPVNICCI ) with pulse pressure variation calculated manually from the intra-arterial blood pressure waveform (PPV ART ) (Bland–Alt- man analysis, predictive agreement, Cohen’s kappa).
RESULTS The mean of the differences
standard deviation (95% limits of agreement) between BP NICCI and BPART was 11
10 mmHg (-8 to 30 mmHg) for mean blood pressure (MBP), 3
12 mmHg (-21 to 26 mmHg) for systolic blood pressure (SBP) and 12
10 mmHg (-8 to 31 mmHg) for diastolic blood pressure (DBP). In error grid analysis, 54% of BP NICCI and BPART MBP measurement pairs were classified as ‘no risk’, 43% as ‘low risk’, 3% as ‘moderate risk’ and 0% as ‘significant risk’ or ‘dangerous risk’. The mean of the differences between PPV NICCI and PPV ART was 1
3% (-4 to 6%). The predictive agreement between PPVNICCI and PPV ART was 80% and Cohen’s kappa was 0.55.
CONCLUSIONS The absolute agreement between BP NICCI and BPART was not clinically acceptable. We recommend not using the current version of the NICCI system for blood pressure monitoring during surgery. The absolute agreement between PPVNICCI and PPVART was clinically acceptable with moderate predictive agreement regarding pulse pressure vari- ation categories. The NICCI system needs to be further devel- oped and re-evaluated when an improved version is available.
TRIAL REGISTRATION The study was registered in the German Clinical Trials Register (DRKS00023188) on 2 October 2020.