Sunday, December 12, 2010

Umbilical vein catheterization technique

Umbilical vein catheterization may be a life-saving procedure in neonates who require vascular access and resuscitation. The umbilical vein remains patent and viable for cannulation until approximately 1 week after birth.
Umbilical vein catheters (UVC), are used for exchange transfusions, monitoring of central venous pressure, and infusion of fluids (when passed through the ductus venosus and near the right atrium); and for emergency vascular access for infusions of fluid, blood products or medications.
Usually in the emergency department peripheral access is preferred for critically ill newborns and if this is impossible, umbilical vein catheterization may be attempted.

Technique :
# The umbilical cord stump and surrounding abdomen should be sterilized with a bactericidal solution. Sterile drapes should be placed.
# A purse-string suture or umbilical tape is tied around the base of the stump to provide hemostasis and to anchor the line after the procedure.
# Using the scalpel, the cord is cut horizontally, approximately 1.5-2 cm from the abdominal wall. Two thick-walled small arteries and one thin-walled larger vein should be identified. The umbilical vein may continue to ooze blood.
# Hemostasis is achieved through tightening the umbilical tape or suture. The arteries do not usually bleed secondary to vasospasm.
# Forceps are then used to clear any thrombi and dilate the vein.
# A 3.5F catheter is used for preterm newborns, and a 5F catheter is used for full-term newborns.
5F umbilical catheter. Note proximal attachment for stopcock


# The catheter should be flushed with pre-heparinized solution and attached to a closed stopcock.
# The catheter is then grasped 1 cm from its distal tip with the iris forceps and gently inserted, aiming the tip toward the right shoulder. Advance the catheter only 1-2 cm beyond the point at which good blood return is obtained. This is approximately 4-5 cm in a full-term neonate. If resistance is initially met, loosen the umbilical tape or suture and manipulate the angle of approach.
Insertion of umbilical vein catheter
# Do not force the advancement.
# Secure the catheter with a suture through the cord, marker tape, and a tape bridge.
# The position of the catheter must be confirmed radiographically. A properly placed umbilical vein catheter appears to travel cephalad until it passes through the ductus venosus.
# Standardized graphs estimate the length of catheter insertion based on shoulder-to-umbilicus length. Alternatively, the shoulder-to-umbilicus length may be multiplied by 0.6 to determine a length that leaves the tip of the catheter above the diaphragm but below the right atrium.
# In an emergency resuscitation, the catheter is best advanced only 1-2 cm beyond the point at which good blood return is obtained.

No anesthesia is typically required for the procedure.

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