critical care medicine
How To Do Peripheral Vein Cannulation, Ultrasound Guided
Additional Considerations for US Guided Peripheral Vein Cannulation
There are, in general, 2 views used in ultrasound-guided peripheral venous cannulation. The short-axis (transverse, cross-sectional) view usually is preferred because it is easy to obtain and is the best view for identifying veins and arteries and their orientation to each other. However, the transverse view shows the needle only in cross-section (hyperechoic [white] dot), and the needle tip can be distinguished only by the appearance and disappearance of the white dot as the imaging plane traverses past needle tip. The long-axis (longitudinal, in-plane) ultrasound view is technically more difficult to obtain (must keep probe, vein, and needle in one plane), but the entire needle (including the tip) is imaged continuously, which ensures accurate intraluminal placement. Increasing narrowness of peripheral veins increases the difficulty of obtaining the longitudinal view. 