A Difference in Subclavian Vein Catheterization Between Supine and Lateral Tilt Position - Stage II

Central venous catheterization is widely used for various purposes during surgery. For central venous catheterization, subclavian vein is selected because of the relatively low risk of infection, long-term patency and low patient discomfort. The cross - sectional area of the subclavian vein is an important factor to increase success rate. Several studies have reported that the Trendelenburg position increases the cross-sectional area of the subclavian vein, and the lateral tilt position can change the cross-sectional area of the subclavian vein. However, the impact of lateral tilt position to the cross-sectional area of the subclavian vein is not clear. The ipsilateral position can increase the cross-sectional area of the subclavian vein, and the contralateral position can decrease the cross-sectional area by gravity. In the second stage of this study, the investigators would like to compare the success rate, the number of needle passage, time to complete subclavian vein catheterization in supine and ipsilateral tile position.