Validation study of Nexfin® continuous non-invasive blood pressure monitoring in critically ill adult patients.
BACKGROUND
Nexfin® (BMEYE, Amsterdam, The Netherlands) is a totally non-invasive blood pressure and cardiac output (CO) monitor based on finger arterial pulse contour analysis.


METHODS
We performed an open observational study in a mix of medical-surgical-burns critically ill patients (N.=45) to validate Nexfin obtained blood pressures (MAPnex) against PiCCO (MAPfem) derived blood pressure measurements. MAPnex, MAPfem and corresponding systolic (SBP) and diastolic (DBP) blood pressures were measured continuously and registered with a 2 hour interval during the 8-hour study period. Statistical analysis was performed by Pearson regression, Bland and Altman, Concordance plot and Polar plot analysis.


RESULTS
MAPnex shows excellent correlation with MAPfem (R² 0.88, mean bias ± LA -2.3±12.4 mmHg, 14.7% error) and may be used interchangeably with invasive monitoring. The excellent MAPnex -MAPfem correlation was preserved in subgroup analysis for patients with severe hypotension, high systemic vascular resistance, low CO, hypothermia and in patients supported by inotropic/vasopressive agents. MAPnex is able to follow changes in MAPfem during the same time interval (level of concordance 85.5%). Nexfin SBP and DBP show significant correlation with PiCCO but the criteria for interchangeability were not met. Finally, polar plot analysis showed that trending capabilities were excellent when changes in MAPnex (ΔMAPnex) were compared to ΔMAPfem (96.1% of changes were within the level of 10% limits of agreement).


CONCLUSIONS
In this sample of critically ill patients we found a good correlation between MAPnex and invasive blood pressures obtained by PiCCO.
Department of Intensive Care Medicine, Ziekenhuis Netwerk Antwerpen, ZNA Stuivenberg, Antwerpen, Belgium.
K
K
Ameloot
K
K
Van De Vijver
N
N
Van Regenmortel
I
I
De Laet
K
K
Schoonheydt
H
H
Dits
O
O
Broch
B
B
Bein
M L
ML
Malbrain
D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000295:instrumentation*; D002302:Cardiac Output; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*