Eighteen healthy subjects were placed in a flat, supine position for measurements of the cross-sectional area (CSA) of the RIJV using vascular ultrasound. Three measurements were obtained at each of the five anatomic levels of the neck. The first baseline measurement was taken at the level of cricoid cartilage (0 cm), followed by measurements at 4 other levels: cephalad to the cricoid cartilage at +1 and +2 cm, and caudad to the cricoid cartilage at -1 and -2 cm. Factors that may influence the RIJV size, including age, gender, and body surface area, were included in the data analysis. The results showed that the average CSA of the RIJV at the five levels measured (from -2 to +2 cm) were 0.91, 0.97, 1.06, 1.10, and 1.14 cm2, respectively. Statistically significant difference in the CSA was noted from the -2 to the +2 cm levels. No differences were found based on age, gender or body surface area. We have concluded that the anatomic level of the neck in relation to the cricoid cartilage at which jugular puncture is performed should be considered together with other maneuvers that may increase RIJV size. Success of RIJV cannulation may be increased by accessing the vein at a point with the largest CSA -1 to 2 cm caudad of the cricoid cartilage especially in cases when the patient does not tolerate Trendelenburg position or ultrasound guidance is not available. One manuscript was published in the Journal of the Association for Vascular Access.
