Effective Sphygmomanometer Based Non-invasive Central Venous Pressure Measurement In Hospitalized Heart Failure Patients

Abstract

<h3>Background</h3> : Central venous pressure (CVP) estimation is vital in treating patients with heart failure (HF) exacerbation, with the measurement being routinely performed via physical examinations, which can frequently be difficult to obtain. This difficulty is further compounded in the age of expanding telemedicine, limiting the physicians' ability to care for HF patients remotely. A simple and accurate non-invasive measurement of CVP is needed. Recently a non-invasive device using a sphygmomanometer pump and oscillometric method to measure enclosed-zone CVP (ezCVP^TM) was developed (Nihon Kohden, Corp., Japan) and was found to accurately predict invasively measured CVP. However, whether ezCVP correlates with the clinical outcome or can be used to guide clinical management is unknown. We conducted a pilot study to assess its clinical utility of this novel technology in managing hospitalized patients with a primary diagnosis of HF exacerbation. <h3>Methods</h3> : Patients admitted to the HF inpatient service were enrolled. Both HF with reduced ejection fraction and preserved ejection fraction were included. Major exclusion criteria included patients in atrial fibrillation, on inotrope, on renal replacement therapy, or have severe tricuspid valve regurgitation. Daily measurement of ezCVP was performed and values were converted to CVP_NI (CVP non-invasive) as previously described. The treatment team was blinded from the CVP_NI values. We correlated the CVP_NI values with the hospital course and parameters such as weight and renal function. Finally, we compared the length of hospital stay between patients who had high or low admission CVP_NI values. <h3>Results</h3> : 22 patients were enrolled in this pilot study, and overall the patients' CVP_NI value decreased as they received diuresis. 8 patients had CVP_NI below the detection limit of ∼2 mmHg (shown as "0") upon admission and remained unchanged. The CVP_NI values upon discharge were overall low (mean +/- SD: 5 +/- 7, median 0). 3 patients had an increase in CVP_NI at discharge, 2 of them had worsening HF and were transitioned to comfort care and therefore the increase in CVP_NI was clinically consistent. The patients with low CVP_NI values upon admission had a shorter length of hospital stay compared to patients with higher CVP_NI values. <h3>Conclusion</h3> : CVP_NI correlated with the clinical course of HF patients receiving diuresis. Admission CVP_NI value was also predictive in overall length of stay in the hospital. This pilot study showed the feasibility and utility of using CVP_NI measurement as part of inpatient HF care. A larger study to confirm these findings is needed.