Comparison of accuracy of central venous pressure (CVP) estimation in internal jugular vein (IJV) by ultrasound and conventional method (using saline column): An observational study

Aim & background: Central venous pressure (CVP) is needed in acute resuscitation and in intensive care unit patients to monitor hemodynamics and to guide fluid resuscitation.
The primary objective of our study is to compare the ultrasound (USG) guided measurement of CVP with conventional measurement of CVP using saline column.
Methods: The study is Prospective observational study. The study was conducted at a tertiary care teaching hospital from February 2020 to December 2021.
245 patients were included in this study using convenient sampling technique.
The primary measure in this study is to assess whether the accuracy of USG measurements (non invasive) of CVP is as good as conventional measurements (invasive) of CVP using saline column method. 
Results: The CVP measurements measured invasively and non invasively were categorized as below normal, normal, and above normal. Using CVP (saline) as the gold standard, for CVP (USG) and CVP (saline) a 3 x 3 contingency table had been made. To compare the diagnostic accuracy between CVP(Saline) and CVP(USG) where the measurements were categorised, Kappa statistics has been used to measure the agreement between the two {CVP (saline) and CVP (USG)}. The Kappa value was found to be around 96.33% and after weightage was 97.96% which was almost perfect agreement.
Conclusion: Based on our study, we conclude that the USG guided measurement of CVP is as good as conventional measurement of CVP using saline column.