Non-invasive central venous pressure estimation by ultrasound-guided internal jugular vein cross-sectional area measurement

Purpose.Central venous pressure (CVP) is widely used in clinical practice as a tool in assessment of fluid status and fluid responsiveness.It is however an invasive monitoring tool and fraught with many untoward complications.This research aims to ascertain if ultrasound-guided measurements of the cross-sectional area (CSA) of the internal jugular vein (IJV) has any correlation with conventional CVP values.Methods.A prospective observational study was conducted for a period of two months.Patients presenting to the operating room or admitted to the Intensive Care Unit who had placement of a central venous catheter were sequentially selected and informed consent obtained.All patients had their right IJV dimensions measured by ultrasound using a high frequency 12 MHz vascular surface probe.Measurements obtained included the CSA and circumference of the IJV before insertion of the central line.Central line was placed, CVP was then recorded and the CVP values and the IJV dimensions were correlated.Results.A total of 43 patients were enrolled, but valid data were obtained only from 40.There was a strong correlation between the CSA of IJV with CVP readings (Pearson correlation coefficient, r=0.559,p<0.001).Also the correlation between the circumference and recorded CVP was found to be statistically significant (r=0.481,p<0.001).Regression formulae were constructed to calculate CVP from IJV circumference as well as CSA.Conclusions.There is a strong correlation between sonographically measured IJV CSA and catheter-measured CVP.In patients having contraindications for a central catheter, non-invasive sonographic measurement of CVP may be a reliable option.