NEW YORK (Reuters Health) – In neonatal resuscitation, routing of a central venous catheter via the umbilical vein can be reliably guided by thoraco-abdominal X-ray or ultrasound, while the position of the catheter tip is most accurately determined by ultrasound.

Those findings are reported in Resuscitation online December 6 by Dr. Fabrice Michel and colleagues with the Centre Hospitalo-Universitaire Nord in Marseille, France.

“We now systematically control catheter position using US (ultrasound) in our unit,” they comment.

The authors explain that while central venous access in neonates is most easily obtained through the umbilical vein, it’s possible for the catheter to end up in the liver, or to be advanced too far so that the tip enters the right atrium or even the left atrium via the foramen ovale.

Most often, thoraco-abdominal antero-posterior X-ray (TAX) is used to confirm the catheter routing and tip position, but recent studies have indicated that ultrasound (US) guidance may be more accurate, they continue.

This prompted the team to compare the two methods in 60 neonates requiring placement of 61 umbilical venous catheters. TAX was used to control the catheter position, and then independent US examinations were performed. The actual catheter route and tip position were determined jointly by senior pediatric radiologists and neonatologists.

Based on this “gold standard” judgment, 28 catheters were correctly routed into a central placement and 15 were adequately positioned in the inferior vena cava. Agreement with these determinations was 85% using TAX and 95% using US, the report indicates.

In terms of the actual catheter tip position, TAX results were concordant with the gold-standard determinations 64% of the time while US concordance was 95%. Furthermore, the accuracy of TAX in defining the tip position decreased with increasing birthweight, the authors found.

“Our results indicate that US should replace TAX for determining UVC (umbilical venous catheter) route and tip position in most neonates,” Dr. Michel and colleagues conclude.

“US examination is not available in all NICUs,” they point out, “but we encourage NICU practitioners to develop this technique.”

Reference:

Comparison of ultrasound and X-ray in determining the position of umbilical venous catheters

Resuscitation 2011.