743 - Vascular Access Challenges in Tiny Babies: Can Intravascular Electrocardiography (IV-ECG) Facilitate Placement of Umbilical Venous Catheters (UVCs) and Improve Safety by Detecting UVC Migration?

Publication Number: 2725.743

Christiane Theda, Royal Women's Hospital, Parkville, Victoria, Australia; Alison G. Martin, Royal Women's Hospital Melbourne, Parkville, Victoria, Australia; Mubin Yousuf, Royal Women's Hospital, Carlton, Victoria, Australia

Background: Care of tiny babies poses unique challenges. Stable central vascular access is essential for their care. But establishing and safely maintaining venous access in this patient group can be extremely challenging. Umbilical venous catheters (UVCs) are often used early in life.

Objective: We are currently investigating utility of intravascular electrocardiography (IV-ECG) to assist with placement and safe maintenance of UVCs. Our observational trial (using a new medical device) includes recruitment of tiny babies. The objective for this abstract is to show examples of the potential utility of IV-ECG in tiny babies (defined here as birth at a gestational age (GA) of < 25 weeks OR < 26 weeks GA with a birth weight (BW) of < 500 grams).

Design/Methods: In our trial, with parental consent, IV-ECG is recorded during UVC placement using an in-line adapter to record the IV-ECG signal as it is conducted from the catheter tip via the saline column; IV-ECG characteristics vary according to position of the UVC inside the body. For the trial, x-ray or ultrasound (US) is used to confirm UVC position. On subsequent days, an adapter can be reintroduced to obtain further IV-ECGs to determine if the UVC tip location has changed (spotchecks); an US is done at times of IV-ECG spotchecks. We focus here on tracings obtained from 4 tiny babies.

Results: Fig 1: Case 1 (23+3 wks GA, 538 g BW): IV-ECG just after UVC insertion: large P wave indicated that the UVC was in too far (x-ray confirmed). Withdrawing the UVC with IV-ECG connected, the reduction in P-wave was seen in real time until it became negative, indicating an appropriate and safe position (x-ray confirmed).
Fig 2: Case 2 (24+5 wks GA, 763 g BW): spotchecks on 3 consecutive days showed that the UVC remained in a good position. Gentle pressure on the abdomen pushes the UVC slightly into the atrium (on US), resulting in a large P. Case 3: (24+6 wks GA, 704 g BW): 2 spotchecks showed UVC in good position.
Fig 3: Case 4 (25+1 wks GA, 470 g BW): 5 spotchecks over 8 days. Early on, the UVC was quite mobile (confirmed by US); this resulted in proper securement. Later, IV-ECG indicated the UVC was again too far in (confirmed by US), resulting in adjustment to keep the catheter in a safe location.

Conclusion(s): Our observational trial is ongoing, but cases presented demonstrate how IV-ECG could assist with placing UVCs in tiny babies in an accurate position quicker and reduce radiation exposures. In addition, spotchecks allow for line monitoring during longer indwelling times and facilitate detection of line migrations that can pose significant risks, especially in tiny babies.

Figure 1. Case 1. UVC Adjustment
Case 1: Adjustment of UVC from (1A) atrial position, indicated by large P wave, via (1B), reduced P wave size, to (1C) correct position (below atrium) indicated by negative P wave


Figure 2: Case 2 and 3. UVC Spotchecks
Case 2: (2A) UVC at good position at baseline; negative P wave and then (2B) UVC tip into atrium with abdominal pressure; positive P wave. Case 3: (2C) UVC in good position; P wave negative.


Figure 3: Case 4. Several spotchecks finding UVC at variable positions
Case 3: UVC found at variable positions. (3A) UVC too far in, very peaked P wave. (3B) UVC still in atrium but P wave less prominent. (3C) UVC in good position with negative P wave.