3. Take time and care to dilate lumen artery before

attempting to insert catheter.

4. Catheter should not be forced past an obstruction.

5. Never advance catheter once placed and secured.

6. Loosen umbilical tie slightly upon completion of procedure and obtain radiographic confirmation of

position.

7. Avoid covering the umbilicus with dressing. Dressing may

delay recognition of bleeding or catheter displacement.

8. Always obtain radiographic (including a lateral view) or

ultrasound (15) confirmation of catheter position.

(16,17).

9. Be certain that catheter is secure, and examine frequently when infant is placed in prone position,

because hemorrhage may go unrecognized.

Fig. 29.1. Graph for determination of length of catheter to be

inserted for appropriate low aortic or venous placement. Length of

catheter is measured from umbilical ring. Length of umbilical

stump must be added. The shoulder–umbilicus distance is the

perpendicular distance between parallel horizontal lines at the

level of the umbilicus and through the distal ends of the clavicles.

(Adapted from Dunn P. Localization of the umbilical catheter

by postmortem measurement. Arch Dis Child. 1966;41:69, with

permission.)

A B

Fig. 29.2. A: Graph for distance of catheter insertion from the umbilical ring for L3, L5, and aortic

bifurcation. Large dots represent catheters positioned at L4. B: Graph for catheter insertion to level T8

using total body length. (From Rosenfeld W, Biagtan J, Schaeffer H, et al. Evaluation of graphs for insertion of umbilical artery catheters below the diaphragm. J Pediatr. 1981;98:628, with permission.)

158 Section V ■ Vascular Access

10. Take care not to allow air to enter the catheter. Always

have catheter fluid filled and attached to closed stopcock prior to insertion. Check for air bubbles in catheter before flushing or starting infusion.

11. When removing catheter, cut suture at skin, not on

catheter, to avoid catheter transection.

E. Technique (See also Umbilical

Catheterization on

the Procedures Website)

Anatomic note: The umbilical arteries are the direct continuation of the internal iliac arteries. Their diameters at

their origins are 2 to 3 mm. As they approach the umbilicus,

their lumina become small and the walls thicken significantly. In a full-term infant, each artery is approximately

7 cm long (Fig. 29.4). A catheter introduced into the umbilical artery will usually pass into the aorta from the internal

iliac artery. Occasionally, it will pass into the femoral artery

via the external iliac artery or into one of the gluteal

arteries. The latter two sites are unsuitable for sampling,

pressure measurement, or infusion.

1. Placement of UAC in high position should be used

exclusively. In rare cases if high position is not successful a low position can be used (Fig. 29.5).

High position is associated with fewer episodes of

blanching and cyanosis of the lower extremities (18).

High catheters were found to have decreased incidence

of clinical vascular complications with a relative risk of

0.53 (95% confidence interval, 0.44 to 0.63) with no

statistically significant increase in any adverse sequelae,

including the incidence of hypertension, intraventricular hemorrhage, hematuria, necrotizing enterocolitis,

or death (19).