Point-of-care ultrasound (POCUS) allows for bedside assessment of the internal jugular vein (IJV). Increases in IJV diameter on ultrasound during the Valsalva maneuver in patients with low right atrial pressure have been described.1 We recently demonstrated that POCUS successfully detects an increase in IJV size during inspiration that is consistent with Kussmaul’s sign.2 We now report that POCUS also demonstrates an increase in IJV diameter with bending forward in healthy non-obese individuals free of known cardiac or pulmonary conditions.
The POCUS images (Figure 1 ) show that the IJV size increases as a senior author bends forward from a sitting position. The images were acquired with the author holding the POCUS probe halfway up the right side of the neck while sitting and bending.
Supplementary Video 1 shows the large increase in the diameter of the IJV when rapidly bending forward and then a decrease in the IJV when sitting back upright. During this time there was no increase in the carotid artery diameter. This observation has been confirmed in two other study authors using the same methodology. The increase in IJV diameter was present each time with repeated bending maneuvers on serial testing.
Here, we report that the IJV size increases in individuals free of known cardiac or pulmonary response when they bend forward. Thus, an increase in IJV size during bending should not be interpreted as a pathological response. Further, this observation provides clinicians another technique, besides the Valsalva maneuver, that can help identify a diminutive IJV when performing POCUS.