ef fects of the valsalva maneuver and head rotation on internal jugular vein diameter and location by ultrasonography

in order to determine the effect of valsalva maneuver and head rotation on the internal jugular vein (ijv) diameter and cross-sectional area and overlap with the carotid artery (ca) and find the best technique for safe cannulation of the ijv and decrease the risk of ca puncture, the diameter of both the ijv and the ca and percentage of overlap between the two vessels and cross-sectional area of the ijv were measured by ultrasonography on the right side of the neck in the supine, head down position, at three different degrees of head rotation with and without the valsalva maneuver in 30 subjects. the results were analyzed by two-way repeated- measures analysis of variance followed by least significant difference (lsd). head rotation increased the overlap between the two vessels (p<0.001). valsalva&apos;s maneuver also increased overlap between the twp vessels (p<0.02) and increased ijv diameter and cross-sectional area (p<0.001). head rotation did not change ijv diameter and cross-sectional area significantly (p>0.05). valsalva&apos;s maneuver and head rotation did not change ca diameter significantly (p>0.05). we therefore advocate the neutral head position with valsalva&apos;s maneuver as a safe and reliable method for ijv cannulation.