A portable ultrasound machine defined the 鈥渢op鈥?of the right internal jugular vein in 44 patients from a single tertiary hospital. The vertical height from this point to the sternal angle was used to estimate CVPIJV. A central venous catheter was then inserted and direct measurement of CVP was made with a pressure transducer. A normal CVP was defined as 3 to 6 mm Hg.
For overloaded patients, CVPIJV correlated well with CVPCVC, P = .004, sensitivity of 64.3%, specificity of 81.3%, and positive predictive value of 85.7%. The area under the curve for the receiver operating characteristic curve was 0.73 (95%confidence interval, 0.59-0.86). For undervolumed patients, the correlation remained statistically significant, P < .001, sensitivity of 88.9%, specificity of 77.1%, and negative predictive value of 96.4%. The area under the curve was 0.83 (95%confidence interval, 0.70-0.96).
Ultrasound estimation of CVP using a portable ultrasound machine and the internal jugular vein is simple, noninvasive, and accurate.