Relationship between the right internal jugular vein and carotid artery at ipsilateral head rotation.

Ultrasound-guided right internal jugular vein catheterization (RIJV) should be the first choice to decrease the catheter-related complications in high-risk hemodialysis patients. For this procedure, clinicians should identify the optimum positions of the RIJV, including its lower overlap with the carotid artery (CA) and high cross-sectional area of the vein. The aim of this prospective randomized study to evaluate the effects of mild ipsilateral head rotation combined with Trendelenburg position on RIJV cross-sectional area and its relation to the CA in adult patients. Forty ASA I-II patients who were undergoing elective surgery were enrolled for this study. The subjects were asked to remain supine in the 15-20° Trendelenburg position. Two-dimensional ultrasound was then used to measure the degree of overlap between the RIJV and CA, the cross-sectional area of the RIJV. These measurements were compared between head rotation to the >30° left, <30° left, neutral, and <30° right positions. When the head was in the >30° left position, overlap was seen in 38 of 40 patients (95%). As the head was rotated from >30° left to <30° right, the CA-RIJV overlap (from 95% to 57.5%), and the cross-sectional area (from 14.2 mm to 8.7 mm) significantly decreased. In conclusion, when the head was turned to <30° right, the CA-RIJV overlap significantly decreased, and the cross-sectional area also decreased. When clinicians determine the optimal head position before RIJV cannulation, it is important to consider the advantages and disadvantages of the different head positions from >30° left to <30° right.