ABSTRACT
Figure 23.1 shows the abdomen. Two tubes passing over the umbilicus are umbilical artery and vein catheters. They can be distinguished by their course, the umbilical artery catheter passes inferiorly to join the internal iliac artery before passing superiorly. The tip should lie between T6 and T9 vertebral level to avoid major branches. The umbilical venous catheter passes superiorly to the left portal vein, passing through the ductus venosus into the inferior vena cava (IVC). The tip should lie within the upper IVC or at the border with the right atrium. In Figure 23.2, the tip of a nasogastric (NG) tube is seen overlying the stomach. Aspiration and radiographs are typically used to check the position.
