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

Abstract

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. © 2008 The Authors.