The femoral vein lies 0.5 to cm medially Alternatively, use ultrasound to identify the vein and its relationship to the artery Catheter length can be estimated as the distance from the insertion site to the umbilicus Cleanse the site with antiseptic solution and allow to dry Wearing sterile gloves, mask, and gown, drape the area Check all equipment and attach the syringe to the introducer needle Repalpate the femoral artery Hold the syringe/introducer needle parallel to the blood vessel and 30 degrees above the horizontal ( Fig 130.5A ) Stabilize it with the heel of the lateral aspect of the hand against the child’s leg Puncture the skin 0.5 to cm medial to the arterial pulsation Apply gentle suction to the syringe while advancing the needle When venous blood returns, advance the introducer needle to mm and recheck for flow Stabilize the needle, and detach the syringe Place a gloved thumb over the open needle hub to decrease bleeding Using the free hand, insert the guide wire (J tip or soft straight tip) through the introducer needle ( Fig 130.5B ) into the vein Pass the wire several centimeters beyond the tip of the introducer needle in a cephalad direction into the vein If it does not pass easily, the introducer needle tip is usually not in the lumen of the vein If so, remove the wire and reposition the needle to establish blood flow again Then reintroduce the wire Stabilize the wire with the hand that inserted it, and gently withdraw the introducer needle from the vein along the wire ( Fig 130.5C ) Move the hand to stabilize the guide wire proximally once the wire is exposed at the puncture site Support the wire and pull the introducer needle off the guide wire Make a small incision at the skin puncture site where the wire emerges, and pass the dilator over the wire to dilate the soft tissue located between the external surface of the skin and the vessel, being careful not to kink the wire Remove the dilator from the wire, leaving the wire in place Pick up the infusion catheter at the proximal end and advance it over the wire to the skin entry site Twist it at the skin entry site ( Fig 130.5D ) to facilitate passage through the soft tissue, and advance it over the wire in a cephalad direction while stabilizing the wire distally Last, as in Figure 130.5E , withdraw the wire while holding the catheter in place; blood flows immediately if the vein has been cannulated Suture the catheter in place, and attach the infusion system to the catheter Location of the catheter should be documented with a radiograph or with ultrasound Ensure that throughout the procedure, the wire is visible and can be grasped at all times if necessary