Pediatric emergency medicine trisk 4336 4336

nonthrombogenic umbilical catheter, 3.5, 4 Fr (premature babies) or, 5Fr (fullterm); infusion solution, often normal saline, containing heparin (1 U/mL).

Procedure
During the catheterization, monitor heart rate and pulse oximetry, and keep the
infant under a radiant warmer to maintain normothermia. Figure 130.8A shows
the pertinent anatomy. Historically, there has been debate regarding optimal
catheter tip location to prevent complications, but emerging evidence suggests
that placement of the catheter in the “high” (T6–T9) rather than “low” (L3–L4)
position may be preferred.
Place the infant supine in the frog-leg position and restrain him/her as
necessary. Gauze pads may be wrapped around the ankles and wrists and either
pinned or taped securely to the bed/sheet. Wearing mask, gown, and gloves, hold
the sterile umbilical catheter over the infant to measure the vertical distance from
the lateral aspect of the clavicle to the umbilicus. The catheter will be advanced
into the artery 60% of this distance, beginning at the skin surface, so its tip will
reach the bifurcation of the aorta, the subdiaphragmatic (i.e., “low”) position. For
catheters to be placed in the “high” position, use the nomogram ( Fig. 130.8A ) to
establish the appropriate insertion length. Recommended insertion lengths do not
account for the length of catheter that is within the umbilical stump from the
abdominal wall. Mark the catheter appropriately and attach it to the T-connector,
stopcock, and syringe. Flush it, leaving it full of fluid. While lifting the umbilical
cord with gauze in one hand, scrub the lower umbilical cord and abdomen from
the xiphoid process to the symphysis pubis with povidone-iodine solution. Drape
the infant on both sides by folding two drapes into triangles or use an aperture
drape; cover the area below the umbilicus with a third square drape.
At the base of the umbilical stump, suture a 3-0 or 4-0 silk tie around the cord
to make a purse string, but leave the knot untied. While holding the gauze on the
nonsterile distal umbilicus, sever the cord 1.5 to 2 cm above the abdominal wall
with the scalpel as shown in Figure 130.8B , part A. Remove the cut umbilicus
and gauze from the sterile area. Bleeding is usually minimal, stopping with gentle
pressure or wiping; rarely, the purse string must be tightened.

Locate the umbilical vessels, usually two thick, white-walled arteries on one
side, and a larger, thinner-walled vein on the other. If the arteries in the stump are
tortuous, cut it closer to the abdominal wall to facilitate cannulation.
Attach two clamps on opposite sides of the umbilicus, being careful to grasp a
fibrous portion of the cord and not just Wharton jelly or an artery. Evert the
clamps to immobilize and expose the cord, and use the small curved forceps, as in
Figure 130.8B , part B, to enter and then stretch the lumen of the artery. Gentle,