How to correctly position the tip of epicutaneous cava catheter in a newborn?

What is it about?

In neonates, chest radiography has been regarded as a practical standard for the verification of correct tip location after catheterization. The interpretation of radiological images is difficult because the validity of radiological landmarks is debated. In neonates, the carina is not always located above the pericardium, as it is in adults; therefore, the carina is not an appropriate landmark for CVC placement. We suggest Intra-procedural verification of tip position by intracavitary electrocardiography (IC-ECG) method. In the IC-ECG method for positioning of the tip, the catheter itself is used as an intracavitary electrode and this can be obtaine filling the catheter itself by saline hypertonic solution. This methodology required a device specifically designed for the IC-ECG. We used Vygocard (Vygon) for easy shifting from surface ECG tracing to intracavitary ECG tracing. We used the defibrillator Defigard 5000 (DG5000, Schiller Medical, Wissembourg) as an ECG monitor. Three electrodes were used: yellow—left shoulder, red—right shoulder, and green—left flank. The IC-ECG focused on lead II (red to green), which is ideal for the visualization of the P wave. After having registrated basal ECG, the red electrode is detached from the shoulder and connected with special Vygocard clip. After that, we begin to position the catheter. We used surface landmark for estimating the length of insertion of catheter from puncture site. The catheter is threaded further on into the venous system; when the tip is 2 cm before the optimal measured position, the catheter is filled with saline hypertonic solution and attached to the connector of the transducer. The surface ECG is switched to the intracavitary ECG, and by watching the variation of the shape of P wave on the intracavitary lead II, it is possible to infer the position of the catheter tip. As the catheter proceeds slowly into the SVC, the P wave gets higher, reaches its peak at CAJ, and proceeding further gradually decreases to become diphasic. To ensure that the tip is well-positioned, it is appropriate to insert the catheter until the P wave becomes diphasic and then pull it back until the P wave is at its peak (positioning that will correspond to the CAJ).

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Why is it important?

The intracavitary ECG method, trough the relief of the maximal P wave, allows you to establish exactly the tip of the catheter in the target zone (CAJ), thus reducing the incidence of malpositions and complications caused by them (arrhythmias; venous thrombosis, pericarditis) It leaves little or no space to x-ray, which can be limited to selected cases, and so reduces newborn’s exposure to x-ray. It reduces the costs because the IC-ECG use–related products are easily available and very cheap.

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