Ultrasonographic detection of very thin percutaneous central venous catheter in neonates

Diagnostic accuracy of ultrasound for localising peripherally inserted central catheter tips in infants in the neonatal intensive care unit: a systematic review and meta-analysis

BACKGROUND

Chest radiography after peripherally inserted central catheter insertion in infants is the reference standard method for verifying catheter tip position. The utilisation of ultrasound (US) for catheter placement confirmation in the neonatal and paediatric population has been the focus of many recent studies.

OBJECTIVE

In this systematic review we investigated the diagnostic accuracy of US for peripherally inserted central catheter tip confirmation in infants in the neonatal intensive care unit (NICU) MATERIALS AND METHODS: We conducted a systematic literature search of multiple databases. The study selection yielded eight articles, all of which had acceptable quality and homogeneity for inclusion in the meta-analysis. Sensitivity and specificity values were reported together with their respective 95% confidence intervals (CI).

RESULTS

After synthesising the eligible studies, we found that US had a sensitivity of 95.2% (95% CI 91.9-97.4%) and specificity of 71.4% (95% CI 59.4-81.6%) for confirming catheter tip position.

CONCLUSION

Analyses indicated that US is an excellent imaging test for localising catheter tip position in the NICU when compared to radiography. Ultrasonography is a sensitive, specific and timely imaging modality for confirming PICC tip position. In cases where US is unable to locate malpositioned PICC tips, a chest or combined chest-abdominal radiograph should be performed.

The superiority of point of care ultrasound in localizing central venous line tip position over time

The primary objective was to study agreement between X-rays and point of care ultrasound (POC-US) in determining central venous line (CVL) tip position. The secondary objective was to examine malposition rates over time using POC-US. Fifty-six neonates were enrolled who had a CVL placed. Initial X-rays and POC-US were obtained. POC-US was performed daily thereafter for the total of 6 days. US video clips were acquired in four standard echocardiographic views: subcostal, four-chamber, and short- and long-axis parasternal views. Gwet's agreement coefficient (AC1) for agreement measured inter-rater reliability of X-rays and POC-US (correct position/malposition). A generalized linear mixed model for binary clustered data estimated malposition rate over time. All analyses were conducted using SAS version 9.4 and Agree Stat. The study included 108 "pairs" of X-rays and POC-US images. Agreement coefficient (AC1), with respect to correct position/malposition of CVL tip, was high AC1 = 0.872 (UVC-AC1 = 0.814, PICC-AC1 = 0.94). Among birth weight (BW) < 1000 g, 1000-1499 g, and BW > 1500 g, AC1 values were 0.922, 0.774, and 0.873, respectively. CVL tip malposition rate decreased over time.Conclusions: Agreement between POC-US and X-rays for CVL tip position was high, with the highest in BW < 1000 g. The data suggest that POC-US can be used for initial confirmation and follow up of CVL tip position. What is Known • X-ray is currently the gold standard for localizing central venous line (CVL) tip position. • Malposition of CVL tip can lead to life-threatening complications. What is New • POC-US is superior to X-ray as it can follow CVL tip position over time, detecting malpositioned lines, adjusting them in a timely manner thus preventing complications. • Standardizing CVL placement, X-ray acquisition, POC-US acquisition with four views with video clips and ultrasound operator training increases accuracy and thus agreement between X-ray and POC-US. • UVC tip is more likely to be malpositoned than PICC tip. Malposition of UVC tip using POC-US decreased over time due to shrinking of the umbilical cord in the first 48 of life.

Use of hand-held ultrasonography to confirm the correct placement of a central venous catheter tip

To avoid severe complications resulting from malpositioning of a central venous catheter, removal and recannulation of the catheter may be necessary, thus wasting medical equipment and increasing stress on the patient. Therefore, central venous catheters should be inserted correctly the first time. We tested whether real-time hand-held ultrasound-guided confirmation of the location of the tip of a central venous catheter inserted from the femoral vein could reduce the rate of malpositioning. Catheters were inserted using conventional methods for 65 patients, and using ultrasound guidance for 29 patients. For the latter group, when a central venous catheter was inserted, the ultrasound examiner first identified its tip located dorsal to the liver in the inferior vena cava and then fixed the catheter in position. We considered a central venous catheter to be malpositioned when its tip appeared in neither the inferior vena cava nor the right atrium-inferior vena cava junction in X-rays. Flexed or inverted catheters were also considered to be malpositioned. We compared the malpositioning rates for the ultrasound and conventional groups. Malpositioning was identified for two (6.9%) patients in the ultrasound group and 19 (29.2%) patients in the conventional group. The relative risk of ultrasound-guided versus conventional catheter insertion was 0.23 (95% confidence interval, 0.09-0.62). Our data suggest that real-time ultrasound monitoring is useful for avoiding malpositioning of central venous catheters inserted from the femoral vein.

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.