Fig. 1
From: Ultrasound-guided peripheral vascular catheterization in pediatric patients: a narrative review
Schematics and ultrasound views of the long-axis in-plane (LAX-IP) and short-axis out-of-plane (SAX-OOP) approaches are shown in a and b, respectively. In the LAX-IP approach, the whole shaft of the needle and the entire course of the target vessel are constantly on the screen during the procedure. In the SAX-OOP approach, the target vessel is visualized in transverse orientation and only the needle tip is traced as a high-echoic point with acoustic shadow on the ultrasound image. The main potential disadvantage of the long-axis in-plane (LAX-IP) approach in pediatric settings (c). In cases approaching small vessels, the probe is easily moved away from the plane at which the ultrasound beam intersects the target vessels at the largest diameter (★)