External Jugular Vein: Another Landmark for Right Internal Jugular Vein Cannulation Using Ultrasound Imaging

Background: Measuring the distance between internal jugular vein (IJV) and external jugular vein (EJV) on ultrasound image can give the information of the whereabouts of the IJV. We compared the success rate between carotid artery (CA)-guided and EJV-guided cannulation based on the information gathered from ultrasound. Methods: We studied 152 patients requiring central venous cannulation during anesthesia. Ultrasound images were obtained with 7.5 MHz probe on the right neck at 0, 30, and maximum rotation of the head in flat and 15o Trendelenberg (T) position. The horizontal diameter of the RIJV and % overlap of the CA with the RIJV at each position, and the horizontal distance of RIJV-REJV at 30o were measured on ultrasound images. In EJV group, the distance of RIJV-REJV was drawn along the cricoid level and the point of IJV was marked as the needle insertion site. Cannulation was performed with palpation of the CA in CA group and performed at the marked point in EJV group without palpation of CA. Results: Overall RIJV diameter was increased in T-position compared to flat position. Following head rotation, RIJV diameter was decreased and % overlap of CA was increased (P ＜ 0.05). In 26.8% of patients at 30 in T position, CA overlapped 26-50% of RIJV. The success rate of cannulation at the first trial was 97.4% in CA group and 96.1% in REJV group. Conclusions: With the IJV identified on ultrasound image, the distance between the IJV and the EJV can be used as another landmark for RIJV cannulation provided the EJV is visualized with the naked eye.