Non-Invasive Central Venous Pressure Measurement Using Enclosed-Zone Central Venous Pressure (ezCVP^TM)

Central venous pressure (CVP) is measured to assess intravascular fluid status. Although the clinical gold standard for evaluating CVP is invasive measurement using catheterization, the use of catheterization is limited in a clinical setting because of its invasiveness. We developed novel non-invasive technique, enclosed-zone (ezCVP^TM) measurement for estimating CVP. The purpose of this study was to assess the feasibility of ezCVP and the relationship between ezCVP and CVP measured by a catheter.

We conducted 291 measurements in 97 patients. Linear regression analysis revealed that ezCVP was significantly correlated with CVP (r=0.65, P<0.0001). The Bland-Altman analysis showed that ezCVP had an underestimation bias of -2.5 mmHg with 95% limits of agreement of -14.1 mmHg and 9.6 mmHg for CVP (P<0.0001). The areas under the curves of receiver operating curve with ezCVP to detect the CVP ≥12 cmH₂O (8.8 mmHg) and CVP >10 mmHg were 0.81 or 0.88, respectively. The sensitivity, specificity and positive likelihood ratio of ezCVP for the CVP ≥8.8 mmHg and CVP >10 mmHg were 0.59, 0.96 and 14.8 with a cut-off value of 11.9 and 0.79, 0.97 and 26.3 with a cut-off value of 12.7.

These findings suggest that ezCVP measurement is feasible and useful for assessing CVP.