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 (BPNICCI) with intra-arterial blood pressure measurements (BPART) (Bland–Altman 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 (PPVART) (Bland–Altman analysis, predictive agreement, Cohen's kappa).

RESULTS 

The mean of the differences ± standard deviation (95% limits of agreement) between BPNICCI 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 BPNICCI 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 PPVNICCI and PPVART was 1 ± 3% (-4 to 6%). The predictive agreement between PPVNICCI and PPVART was 80% and Cohen's kappa was 0.55.

CONCLUSIONS 

The absolute agreement between BPNICCI 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 variation categories. The NICCI system needs to be further developed 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.