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

Objective: Thoraco-abdominal X-ray (TAX) is the most frequent used method to determine the route and tip position (TP) of umbilical venous catheters (UVCs). The aim of this study was to compare ability of TAX and ultrasonography (US) to determine UVC route and TP.

Patients and methods: All neonates requiring UVC or admitted to our Paediatric and Neonatal Intensive Care with UVC were included in this prospective study. Catheter position was controlled by TAX and interpreted by the physician in charge of the patient. US examinations were performed by a paediatric radiologist blinded to TAX result. The UVC route (central or not central) and TP determined by each method were compared to the "actual UVC route and TP", as determined by senior paediatric radiologist and neonatologist referents joint interpretation of TAX and US results.

Results: Sixty-one UVCs were assessed in 60 neonates of mean gestational age of 34.7±4.2 weeks. To determine catheter route, sensitivity and specificity were respectively 96.4% and 93.9% for US and 92.8% and 78.8% for TAX. To determine catheter tip position, sensitivity and specificity were respectively 93.3% and 95.6% for US and 66.7% and 63.0% for TAX (p<0.001). Failure of TAX to define UVC tip position increased with birth weight (p<0.005).

Conclusion: TAX and US are reliable in determining UVC route (central or not) but US examination is superior to TAX in determining UVC TP.