The reliability of 2D and colour Doppler ultrasound in localising longline position.

BACKGROUND: The position of percutaneously inserted central venous catheters (longlines) in neonates is critical, as malpositioned longlines are associated with potentially fatal complications. AIM: To determine if cardiac ultrasound (two-dimensional (2D) and colour Doppler) is useful in evaluating longline position, when compared with the position identified by contrast radiography. SETTING: Single level 3 neonatal unit. PARTICIPANTS: Forty-four neonates undergoing insertion of 24-gauge silastic longlines between July 2004 and September 2005. METHODS: Infants who had a longline inserted underwent echocardiography by a novice and an experienced operator. Operators identified longline position using a 2D then colour Doppler echocardiography during a rapid bolus infusion of saline. The position was identified from contrast radiography by two independent observers. RESULTS: Using 2D echocardiography, the novice and experienced operators could identify 41 and 59% of longlines, respectively. However, only 34% of longlines were identified by both operators. In 15 infants whose longline positions were identified by both operators, there was agreement in only eight infants (53%). Colour Doppler improved the experienced operator's success but did not assist the novice operator. For radiographs, there was 68% agreement on longline position between observers. The experienced echocardiographer located three (7%) longlines within the heart that from radiographs were thought to be in a proximal central vessel. CONCLUSIONS: This technique is experience-dependent and complements rather than replaces the use of contrast radiography. However, some infants with an apparently acceptable longline position on contrast radiography have longlines located within the heart on echocardiography.

Digital imaging does not improve localization of percutaneously inserted central lines in neonates.

OBJECTIVE: To determine whether the use of digital imaging improves the localization of percutaneously inserted central (PIC) line tips compared to standard radiographs, with contrast being used in both cases. METHODS: Digital radiographs taken for localization of PIC lines between October 2002 and September 2003 were identified from the neonatal database. Two reporters independently reviewed the radiographs and stated (i) whether the tip could confidently be seen and (ii) the position. The observers were encouraged to use all the image modification modalities available. The formal radiology report was taken as the third 'reporter'. RESULTS: Overall 117 digital radiographs from 98 infants were reviewed. Reporter 1 identified the tip in 83 (71%); reporter 2 in 84 (72%); and the radiologist in 95 (81%), although all agreed that the tip could be identified in only 55 (47%) radiographs. In radiographs where the reporters agreed that the tip could be identified, they agreed on the position in 37 (67%) cases. In 61 (52%) radiographs the reporters did not agree that the tip could be seen, but they agreed on its position in 36 (59%) cases. The kappa coefficient for agreement on line position was 0.63. The level of agreement between reporters in this study using digital imaging was not significantly different from our previous findings using standard radiography with contrast (74/117, 63% vs 57/96, 59%). CONCLUSION: The use of digital imaging, with its ability to manipulate images in order to identify PIC line tips, is not significantly better than using standard radiography with contrast.