One of the major transformations in medicine right now is the use of point-of-care ultrasound (POCUS) to aid in bedside diagnosis. Recently, investigators tested the utility of POCUS in assessing jugular venous pressure in patients with possible heart failure. The ultrasound assessment used a commercially available handheld probe that connects to a smartphone to display the ultrasound images.
Researchers in Utah used a convenience sample of 100 patients scheduled for right heart catheterization to assess the accuracy of three methods of estimating central venous pressure: ultrasound measurement of jugular venous pressure, visual assessment of jugular venous pressure, and an ultrasound-based qualitative assessment of jugular venous pressure. The first two methods estimated the vertical height of the jugular venous distension with the patient in the semi-upright position, which is lying in a hospital bed raised to an angle of 30-45 degrees. The qualitative ultrasound assessment was performed with the patient sitting upright and was simply whether the jugular vein was at least as large in diameter as the adjacent carotid artery when viewed just above the clavicle throughout the respiratory cycle. All estimates were compared with the right atrial pressure measured during right heart catheterization with pressures of 10 mmHg or greater being considered abnormal.
The mean age of participants was 60 years and females comprised 36 percent of the group. Reduced ejection fraction was present in 56 percent and 41 percent had obesity. For detection of elevated right atrial pressure, quantitative POCUS using a cutoff of over 8 cm had sensitivity of 72.7%, specificity 78.6%, and a positive likelihood ratio of 3.4. The qualitative POCUS had sensitivity of 54.4%, specificity of 94.6%. The visual jugular venous pressure using a cutoff of over 8 cm had sensitivity of 52.9%, specificity of 84.0%. Of note, visual jugular venous pressure was only attempted in 69 patients and was only successfully performed in 42.
There are two important takeaways from this study. First, POCUS can be useful in assessing jugular venous pressure, especially when visual measurement is not possible, for example in the setting of obesity. Second, visual assessment of jugular venous pressure has poor sensitivity. One of the contributions of evidence-based medicine has been to highlight the limitations of many traditional physical exam maneuvers. In this case, we should continue to evaluate jugular venous pressure in assessment of heart failure, but just do it in a more reliable way.
For more information, see the topic Heart Failure With Reduced Ejection Fraction in DynaMed®.
