Dear Editor,
Re: Erratum
In response to the Erratum, the following additional clarifying information is provided with reference to the articles previously published in BJN, which are cited in the Erratum below, by the clinical and scientific experts at Avanos Medical (Alpharetta, GA), manufacturers of the Cortrak* 2 Enteral Access System (EAS) for electromagnetic tracking of feeding tubes during placement.
Currently, there is not a device that can totally eliminate pneumothorax risk. However, clinical studies have consistently shown that Cortrak* reduces the incidence of pulmonary complications when used according to its labelling and with appropriate training (Krenitsky, 2011; McCutcheon, 2018; Bourgault, 2020). Statistics provided by the same group of authors as the publications under discussion here, including Taylor et al (2019), support the benefits of using the Cortrak system as a placement guidance tool, relative to blind placement.
Specifically, Taylor et al (2019) reference that, when placing nasogastric tubes, ‘1–2% enter the lung and 0.25–4% are associated with major complications' (*), and that ‘>90% of lung complications and deaths are associated with misplacement detected too late by an end-of-procedure X-ray or pH testing’. With regard to the Cortrak system specifically, they indicate that there have been ‘over 1 million tubes sold worldwide’. Therefore, at 1–2% misplacements (*), we should be seeing over 10 000–20 000 misplacements, yet the figures provided in Taylor et al (2019) indicate that in the US and UK only 62 have been seen (54 and 8, respectively). This gives a rate of ~0.0062% per million, which is well below (1/160th to 1/320th) the 1–2% rate expected when not using the Cortrak system.
Limitations of this study include, first, analysis of only a small sample size (ie 7 tracings), as acknowledged by the authors. Additionally, any analysis of the accuracy of trace classification methods would be entirely dependent on the positioning of the receiver relative to the xiphisternum at the time of the tracing. This cannot be seen from reviewing traces after the fact, as has been performed for these studies, namely Taylor et al (2019) and the Taylor et al articles published in BJN in 2017 listed in the Erratum.
During the procedure the receiver must be placed with its apex over the xiphisternum to ensure accuracy. If the receiver was placed more superiorly, for example, it could lead to traces that appear to be entering the stomach, when they could be entering higher up (eg into the airway). Therefore, the traces themselves may have been accurate, but due to an inappropriate set-up could be misinterpreted. Despite this risk, the percentage of misplacements is still two orders of magnitude less than expected with blind placements (as calculated above). The importance of accurate receiver placements is emphasised throughout Avanos's training programme.
Finally, it has been mis-stated that the trace printouts lack a depth view in the Taylor et al (2019) article, since the Cortrak system display includes a toggle feature that allows anterior and lateral and/or depth cross-section views. Furthermore, with the system printer attached, images can be generated in all three of these views as provided for by the display.
In conclusion, the Cortrak EAS has consistently been shown to convincingly reduce the incidence of pulmonary complications and incorporates a rigorous training programme that includes pre-learning and classroom activities designed in keeping with current national clinical guidances.