• central venous line
• parenteral nutrition

Percutaneously inserted central venous lines are widely used in neonatal intensive care to administer parenteral nutrition and medications.¹ It is important to ascertain the position of the line tip before use as incorrectly positioned long lines can lead to life threatening complications like cardiac tamponade and pulmonary oedema.^2,3

Reece et al suggested that it is prudent to use a routine contrast radiograph to localise the line tip in newborn infants.⁴ We would like to comment on their suggestion and report a relevant study we carried out on our neonatal unit.

Intravenous water soluble contrast is not commonly used in neonates and very little is known about its potential side effects in premature infants.⁵ Studies have shown that renal clearance is prolonged in premature infants because of renal immaturity.⁶ Data in children have shown a number of possible side effects, including hypotension and cardiac arrhythmia.⁵ Moreover, obtaining an intravenous contrast radiograph of a long line would require additional medical and nursing time as a doctor would have to “gown up” for the procedure. This may not be logistically feasible in some busy neonatal units, especially out of hours.

Reece et al were unable see the line tip clearly in two cases, even after a contrast study.⁴ This was due to delay between the injection of contrast and the radiographer exposing the film. This shows that fine coordination is required between the radiographer and the person injecting the contrast. Specific training may necessary.

We performed a retrospective study of the reliability of plain radiographs in identifying the site of the long line tip in our tertiary neonatal intensive care unit. Over a 10 month period all 27 babies who had long lines inserted were included. In all cases an Epicutaneo-Cava-Katheter (Vygon, UK) was inserted. This is the same catheter as that used by Reece and colleagues.⁴ Our placement aim was also similar to that in their study.⁴

The position of the line tip on the postinsertion x ray was independently reviewed by an experienced junior doctor (IB) and a consultant neonatal radiologist (SB). There was agreement between the two investigators in 25/27 (92.6%) cases. No complications due to line placements were observed during the study period.

We therefore feel that a plain radiograph is the safest, quickest, and cheapest way to ensure the safety of the line.