Caudal Traction of the Arm Improves Supraclavicular Ultrasound Visualization of the Subclavian Vein

Authors: Kim E-H et al. Am J Emerg Med 2016 Feb 11.

The length of puncturable subclavian vein and the available angle for needle insertion were significantly greater with caudal traction compared with a neutral position of the arm.

There is some evidence that a supraclavicular approach to subclavian vein cannulation with ultrasound guidance may be safer than the traditional landmark-based subclavian approach. Using an ultrasound probe placed above the clavicle, investigators in Korea measured the puncturable length of the subclavian vein and the available angle for needle insertion in 20 infants, 20 young children, and 20 adults undergoing general anesthesia. Measurements were taken with the ipsilateral arm in neutral, caudal traction, and abduction positions.

The length of puncturable subclavian vein and the available angle for needle insertion increased significantly with caudal traction compared with the neutral position (increases of 35.6% and 25.0%, respectively), with no decrease in subclavian vein diameter.

COMMENT

Because this was not an interventional clinical trial, our ability to infer patient benefit is limited. Nevertheless, these data suggest that if you plan to use the supraclavicular approach to place a subclavian vein catheter with ultrasound guidance, having an assistant apply gentle caudal traction to the arm may improve your ability to see the vein and puncture it safely.