1. If the line is to be used long term, particularly if parenteral nutrition is to be infused by this route, the same aseptic techniques must be used to prevent linerelated sepsis as are used for any central venous line (see Chapter 34).

2. Keep catheter tip away from origin of hepatic vessels, portal vein, and foramen ovale. Ideally, the catheter tip should lie at the junction of the inferior vena cava and the right atrium. The tip should be at least well into the ductus venosus to protect the liver from receiving inappropriate infusions (5). Sometimes it will not be possible to advance the catheter through the ductus venosus. Vigorous attempts to advance are to be avoided. In an emergency, vital infusions (avoid very hypertonic solutions) may be given slowly after pulling catheter back into umbilical vein (approximately 2 cm) and checking blood return.

3. Check catheter position prior to exchange transfusion. Avoid performing exchange transfusion with catheter tip in portal system or intrahepatic venous branch (see Fig. 32.1).

4. Once secured, do not advance catheter into vein.

5. Avoid infusion of hypertonic solutions when catheter tip is not in the inferior vena cava.

6. Do not leave catheter open to atmosphere (danger of air embolus).

7. Avoid using a central venous pressure monitoring catheter for concomitant infusion of parenteral nutrition (risk of sepsis).

8. Be aware of potential inaccuracies of venous pressure measurements with the catheter tip in the inferior vena cava.

Umbilical venous catheters may be placed within 5 to 7 days of birth, and occasionally up to 10 days after birth.

Anatomic note: In the full-term infant, the umbilical vein is 2 to 3 cm in length and 4 to 5 mm in diameter. From the umbilicus, it passes cephalad and slightly to the right, where it joins the portal sinus, a confluence of the umbilical vein with the right and left intrahepatic portal veins. The portal veins have intrahepatic branches that are distributed directly to the liver tissue. The ductus venosus becomes a continuation of the umbilical vein by arising from the left branch of the portal vein, directly opposite where the umbilical vein joins it. The ductus is located in a groove between the right and left lobes of the liver in the median sagittal plane of the body, at a level between the 9th and 10th thoracic vertebrae; it terminates in the inferior vena cava along with hepatic veins, as shown in Figure 32.1.

1. Make necessary measurements to determine length of catheter to be inserted, adding length of umbilical stump (6, 7, 8, 9, 10). Many formulas and measurements (Table 32.1) (see Chapter 31, Fig. 31.5) have been derived to predict the accurate placement of umbilical catheters; however, there is no universal formula, measurement, or nomogram that can be applied with consistent accuracy across infants of all birth-weight and gestational ages (11), and catheter tip placement must be verified (see 11 and 12 below).

2. Prepare for procedure as with umbilical artery catheter (see Chapter 31, E).

3. Identify thin-walled vein, close to periphery of umbilical stump (Fig. 32.2).

4. Grasp cord stump with toothed forceps.

5. Gently insert tips of iris forceps into lumen of vein and remove any clots.

6. Introduce fluid-filled catheter, attached to the stopcock and syringe, 2 to 3 cm into vein (measuring from anterior abdominal wall).

7. Apply gentle suction to syringe.

a. If there is no easy blood return, the catheter may have a clot in the tip. Withdraw the catheter while maintaining gentle suction. Remove clot and reinsert catheter.

b. If there is smooth blood flow, continue to insert catheter for full estimated distance.

8. If catheter meets any obstruction prior to measured distance

a. It has most commonly (1) Entered portal system, or (2) Wedged in an intrahepatic branch of portal vein