Absolutely! Not only can POCUS be used to estimate the CVP by measuring the jugular venous pressure (JVP), it may also be more reliable than the traditional—often challenging—visual method of looking for internal jugular (IJ) waveforms in the neck.1
To estimate the CVP by POCUS, first position the patient in a comfortable (usually semi-recumbent) position. Select “vascular” (ie, high frequency) setting on your device (linear array probe for traditional ultrasound devices). With the probe in the transverse plane (ie, perpendicular to the IJ) and the orientation marker pointing to the right of the patient, slowly slide the probe cranially until the IJ appears to collapse during end-expiration, a point commonly referred to as the “meniscus” (CLIP 1 below). Measure the vertical distance between the meniscus and the sternal angle and, just as you would using the traditional method, add 5 cm (see limitation below) to calculate the height of the JVP, with values > 8 cm considered elevated (Figure 1 below).1,2,3
You can also look for the point of JVP collapse in the longitudinal axis by rotating the transducer 90° clockwise (CLIP 2 below). Here, the shape of the IJ resembles a wine bottle with the collapsed portion or the tip of the tapered portion or triangle, representing the meniscus.3
A major limitation of estimating the CVP by visualization of JVP or by POCUS is the assumption that the distance between the right atrium and the sternal angle is constant at 5 cm. It turns out that this distance may potentially vary among patients depending on their body habitus and position.4 A cool study from 2015, however, more accurately determined this distance by adjusted ultrasound views of the center of the right atrium. 5 Clearly, bedside estimation of CVP by POCUS will continue to be refined in the future.
Bonus Pearl: Did you know that the traditional non-invasive method of estimating CVP by examining neck veins was first proposed in 1930 by Sir Thomas Lewis, a British cardiologist, who has been called the “father of clinical cardiac electrophysiology” and coined the terms “pacemaker,” “premature contractions,” and “auricular fibrillation”?6,7
Clip 1. Transverse visualization of the internal jugular vein (IJV) by using POCUS. The meniscus is the point of IJV collapse during end-expiration.
Figure 1. Measurement of the jugular venous pressure (JVP) by POCUS. Add 5 cm (green arrow) to the distance between the meniscus (internal jugular collapse on the transverse view or tip of the tapering zone on the longitudinal view) and the sternal angle (red arrow).
Clip 2. Longitudinal visualization of the internal jugular vein (IJV) by using POCUS. The meniscus is the tip of the tapering zone or triangle of the IJV.
Contributed by Woo Moon D.O., Mercy Hospital, St. Louis, Missouri
Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!
References
2. McGee MD S. Evidence-Based Physical Diagnosis. 5th ed. Philadelphia: Elsevier; 2021.
4. Istrail, L. POCUS and the jugular venous pressure: A deep dive. POCUS Med Ed, November 12. 2021. POCUS and the Jugular Venous Pressure: A Deep Dive (pocusmeded.com)
5. Xing C-Y, Liu Y-L, Zhao M-L, et al. New method for nonivasive quantification of central venous pressure by ultrasound. Circulation: Cardiovascular Imaging 2015;8/ https://doi.org/10.116/CIRCIMAGING.114.003085. New Method for Noninvasive Quantification of Central Venous Pressure by Ultrasound (ahajournals.org)
Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!
