Why Is an Umbilical Arterial Catheter Used?

An umbilical artery catheter allows doctors to monitor a baby's blood pressure, collect blood samples, and perform exchange transfusion.

The umbilical cord is a narrow tube-like structure that connects the baby in the womb to the placenta. The umbilical cord and placenta together act as a link between the mother and the developing baby. They provide nutrients and oxygen to the baby and remove waste products from the baby when the baby is in utero. The umbilical cord has three blood vessels: two umbilical arteries and one umbilical vein. The umbilical vein carries nutrients and oxygen to the baby, whereas the umbilical arteries carry waste products from the baby to the placenta for elimination.

An umbilical artery catheter (UAC) is a narrow, soft, and long tube that a medical professional places in the umbilical artery of a newborn baby. The catheter can be used for accessing the umbilical artery during the first 5-7 days of life. Rarely, the UAC may be used beyond 7-10 days after birth. The catheter helps in collecting blood samples from the ill baby without the need for frequent needle pricks. It may also be used to do the following:

• Continuously monitor the newborn baby's blood pressure. Because the catheter is directly placed inside the artery, the blood pressure is measured accurately through the UAC.
• Perform exchange transfusion (slowly removing the baby's unhealthy blood and replacing it with the donor's blood or plasma)
• Perform angiography (imaging test to view the baby's blood vessels)
• Infuse fluids and medications when other routes are not available (the umbilical venous catheter is preferred for the administration of fluids and medications to the baby)

Before placing an umbilical artery catheter (UAC), the baby is restrained for minimizing any movement during the procedure. The doctor then cleans the umbilical cord and surrounding area with an antiseptic solution. The doctor grasps the umbilical cord with a forceps or cord clamp. The doctor then drapes the area and places an umbilical tie around the cord. Further, the doctor cuts the umbilical cord horizontally around 1-1.5 cm from the skin. The doctor identifies the umbilical arteries (normally two in number) by their thick walls and smaller lumen. The doctor places the UAC into the umbilical artery. The doctor takes an X-ray to determine the final position of the catheter. After confirming the correct position of the catheter, the doctor ties a silk thread to secure them in place. They make use of the catheter to secure to the baby's belly area using a tape (umbilical catheter bridge).

The complications of an umbilical artery catheter (UAC) may include the following:

• Perforation or injury to the umbilical vessels
• Infection
• Nerve injury
• Interrupted blood supply to an organ or limb
• Bleeding
• Air embolism (entry of air bubbles in the baby's bloodstream causing blockage of a blood vessel)
• Hypoglycemia (reduced glucose in the baby's blood)
• Hypertension (raised blood pressure)
• Electrolyte imbalance (especially hypernatremia or raised serum sodium levels)
• Injury to an organ or limb
• Broken catheter