Advice

Technology overview

Technology overview

This briefing describes the regulated use of the technology for the indication specified, in the setting described, and with any other specific equipment referred to. It is the responsibility of healthcare professionals to check the regulatory status of any intended use of the technology in other indications and settings.

About the technology

CE marking

CORTRAK 2 EAS was CE marked in September 2012 as a class I self-certified device. CORTRAK enteral feeding tubes are CE marked separately as class IIb devices (since November 2008). Both the system and the tubes are manufactured and distributed by CORPAK MedSystems (USA).

CORTRAK 2 EAS is regulated under the European Medical Device Directive (2007/47/EC).

Description

CORTRAK 2 EAS uses electromagnetic sensing technology to track and display the path of the feeding tube during a placement procedure. The CORTRAK 2 EAS unit must be used with device-specific CORTRAK enteral feeding tubes.

CORTRAK 2 EAS consists of 3 major parts:

  • A portable, battery powered monitor unit (width 31 cm, height 34 cm, depth 8 cm) with an LCD display and touchscreen interface – This unit, which weighs 3.6 kg, contains the electronics and software for the system. The internal rechargeable battery will operate the device for approximately 2 hours (if in continuous use) when fully charged. Charging an empty battery to full capacity takes approximately 4 to 6 hours. The system can also be powered from the mains electricity supply.

  • A single-use polyurethane CORTRAK radiopaque tube and tip (for X‑ray visualisation) – Each tube is supplied with a pre-inserted, single patient-use braided stainless steel stylet with a small electromagnetic coil (transmitter) located at the tip. A cable connects the stylet to the monitor unit. The tube has water-activated C-19 lubricant on the tip and in the internal lumen, an anti-clog exit port and a Y-access port for irrigation, aspiration or feed, allowing a closed system to be maintained. Centimetre markings are printed on the tube to aid placement and check for migration during use. CORTRAK NG feeding tubes are 92 cm long and CORTRAK post-pyloric feeding tubes are either 109 cm or 140 cm long. The feeding tubes are available in 3 sizes: 8, 10 or 12 Fr (French scale: 1 Fr is 0.33 mm). The length and diameter chosen will depend on the patient; for example, smaller tubes are needed for children. A stylet storage bag is provided with each tube.

  • A receiver unit – This tracks the electromagnetic signal from the transmitting stylet throughout the placement procedure. The receiver unit is attached by a cable to the monitor unit, which then provides a graphical display of the feeding tube tip location relative to the receiver unit and track.

An optional printer is available for printing adhesive labels to attach to patient records, detailing the anterior view of the tube track along with patient and operator details.

In practice, CORTRAK 2 EAS can be operated in 2 modes: accounts mode and anonymous mode. There is also an administrative mode which allows access to additional system features not needed during placements.

  • In accounts mode each operator is assigned a unique account consisting of a login name and a password which must be used to perform or review placements. The monitor unit can save video files to an external USB flash drive. These files may subsequently be reviewed on a computer for reference and training purposes.

  • In anonymous mode no operator login is needed. The entire placement video is temporarily held in the monitor unit's memory for immediate review or critique, but is not recorded.

CORTRAK 2 EAS is used as follows:

  • After the person is positioned in accordance with hospital protocol (usually in a semi-upright position) for tube placement, the front of the receiver unit is placed over the xiphoid process (the anatomical landmark for the oesophageal/gastric junction on the lower sternum). The receiver unit, which does not need to be placed directly on the skin, is held in place either by a second staff member or by a stabiliser, which is a weighted accessory available from the manufacturer. The receiver unit is attached by a cable to the monitor unit.

  • The distal end of the stylet (which is pre-inserted into and spans the length of the feeding tube) is connected to the monitor using a short interconnecting cable.

  • The feeding tube (containing the stylet) is inserted via the nostril into the stomach or small intestine.

  • The monitor unit displays a real-time graphical representation of the tube tip path and tip location relative to the receiver unit (not an image of the actual feeding tube position). The track of the tube is shown on the computer monitor with 3D views, obtained from a combination of the 'anterior view' (frontal plane), the 'depth cross-section view' (transverse plane) and the 'lateral view' (sagittal plane) simultaneously (figure 1).

  • If the position of the stylet tip is outside the range of the receiver unit (approximately 30 cm), the monitor unit displays 'Out of range'.

  • When placement is complete, the stylet is disconnected (the stylet cable should remain connected to the monitor unit). The stylet is then removed from the feeding tube, leaving the feeding tube in situ.

  • The stylet can be re-used if placement needs to be confirmed again in the same patient. If re-use is intended, the stylet should be cleansed in warm water or 70% isopropyl alcohol and retained in the stylet storage bag provided (or similar aerated container). The bag should be labelled with the patient's details to ensure single-patient use.

  • To re-use the stylet, the stylet must be re-connected to the monitor unit cable. The tip of the stylet can then be inserted into the centre of the feeding tube and down the length of the tube.

Although the manufacturer indicates that CORTRAK 2 EAS may be used to confirm tube placement instead of X-ray imaging, the instructions for use state that users should ultimately confirm the position according to facility protocol, which may include X-ray or endoscopy depending on tube type.

Figure 1: The CORTRAK 2 EAS monitor unit display during tube insertion (receiver unit shown in blue)

The CORTRAK 2 EAS monitor unit display during tube insertion (receiver unit shown in blue)

CORTRAK 2 EAS is operationally identical to the predecessor system, CORTRAK EAS. All CORTRAK EAS devices have been upgraded to CORTRAK 2 EAS.

Setting and intended use

CORTRAK 2 EAS is intended to guide appropriately qualified operators (medical or nursing staff trained in tube placement and use of the CORTRAK system) in the correct placement of CORTRAK enteral feeding tubes into the stomach or small intestine. The manufacturer states that CORTRAK 2 EAS can also be used for periodic re-confirmation of the placement, or repositioning, of indwelling CORTRAK feeding tubes. This may be useful in situations where the tube may have moved after routine (per hospital protocol) placement checks.

The device is not intended to be used as a training aid for staff learning to place nasoenteral feeding tubes. CORTRAK 2 EAS should not be used in people with implanted medical devices that may be affected by electromagnetic fields. Precautions should be taken with burns patients in identifying the xiphoid process by palpation and placing the receiver unit on the chest.

Healthcare professionals must be trained to use the device according to the instructions for use; CORPAK MedSystems offers a training programme.

CORTRAK 2 EAS is intended to be used in the secondary care setting and is currently being used in a number of NHS hospitals.

Current NHS options

The NICE guideline on nutrition support for adults recommends that enteral tube feeding should be considered in people who are malnourished or at risk of malnutrition and have:

  • inadequate or unsafe oral intake (including both food and drink)

  • a functional, accessible gastrointestinal tract.

According to the British Society of Gastroenterologists guidelines for enteral feeding in adult hospital patients (Stroud et al. 2003), enteral tubes should be placed by experienced medical or nursing staff. NG tubes can be placed without the aid of an endoscope to visualise the digestive system. This is known as 'blind' placement. For post-pyloric tubes (and complex NG tube placements), endoscopic visualisation may be used before either blind placement or placement under fluoroscopic guidance (using fluoroscopy after administering a contrast medium to guide tube placement in real time).

The NICE guideline on nutrition support for adults recommends that the position of all NG tubes should be confirmed after placement and before each use by aspirating the feeding tube and testing the aspirate for acidity using pH paper. Aspirates at pH 5.5 or below indicate placement in the stomach. X-ray may also be used if necessary. For post-pyloric tube placements a confirmatory X-ray should always be done unless the tubes were placed under fluoroscopic guidance.

NHS England issued a Patient Safety Alert in 2013, following reports of 2 deaths after enteral nutrition was unintentionally given into the respiratory tract through a misplaced nasogastric tube inserted with the aid of a placement device. Two similar moderate harm incidents had been reported previously. The placement device used was not stated. The alert states that it is vital that healthcare professionals perform pH or X-ray testing to confirm correct placement of nasogastric tubes after initial insertion even when using placement devices (NHS England 2013). The need for robust systems for supporting staff to deliver safety-critical placement checks of nasogastric tube has been emphasised in a 2016 Patient Safety Alert directed at trust boards (NHS England 2016).

NICE is not aware of any other CE‑marked devices that have a similar function to the CORTRAK 2 EAS.

Costs and use of the technology

The capital components of the CORTRAK 2 EAS system (monitor unit, receiver unit and stylet connecting cable) cost £12,000 excluding VAT. This price also includes a CORTRAK 2 EAS accessory kit (with USB flash drive, stabiliser and levelling device), a replacement battery, a replacement receiver unit, a CORTRAK printer, a charger and a stand for the device. The prices of the consumables, per-procedure and excluding VAT, are:

  • £51 for a NG tube (92 cm long)

  • £103 for a post-pyloric tube (109 cm or 140 cm long).

The lifespan of the system is 5 years. October and Hardart (2009) estimated an average treatment session time of 1.7 hours (102 minutes) for post-pyloric tube placement (the time between taking a post-pyloric tube from stock to confirmation of placement). Taylor et al. (2010) suggested a median time of 17 minutes for post-pyloric placement. Windle et al. (2010) estimated 6 minutes as the mean time of placement, using a sample that included both NG and post-pyloric tubes. The latter 2 estimates, however, do not include setup time or the time to confirmation of tube placement. If it is assumed that 5 tubes can be placed in a day and 1200 tubes placed in a year (240 annual working days), and that CORTRAK 2 EAS use is split equally between NG and post-pyloric tube insertions using a standard annuity method with a discount rate of 3.5%, the estimated average treatment cost per tube placement is £79.

CORTRAK 2 EAS must be used with CORTRAK 2 EAS enteral feeding tubes. The cost of conventional polyurethane (non-CORTRAK) tubes for short-term placement range from as low as £3 (NG, 8 Fr and 10 Fr) to £9 (post-pyloric, 8 Fr) each (NHS supply chain 2015). The routine nature of nasoenteral feeding tube placement means that no information is included in published NHS reference costs. Instead, GP or self-referral plain film X-ray costs are reported to be £30 (Department of Health 2014; code DAPF). Windle (2010) reports a £66 (inflation-adjusted) unit cost for bedside chest X-rays to confirm tube placement, but this is not a national average and only represents the experience of 2 sites in the Mid Yorkshire Hospitals NHS Trust. Market prices suggest the cost of pH-graded paper strips (pH 0–6) is around £9.14 per 100 strips (NHS supply chain, 2015).

Post-pyloric tubes are generally placed using endoscopy. Tubes more suited for long-term placement and use with an endoscope cost around £70 (NHS supply chain, 2015). There is no nationally representative unit cost information available for endoscopically inserting post-pyloric tubes. As an alternative, Windle (2010) notes that the cost of this procedure for a single NHS trust is reported to be approximately £700.

The manufacturer instructions state that users should ultimately confirm the position according to facility protocol. In this case, many of the costs mentioned above (pH strips or X-ray), as well as the usual NHS (labour and facility) costs will still be incurred. Therefore, the difference in cost per treatment session will be the per treatment cost calculated above (£79), minus the cost of a conventional polyurethane tube that is displaced because a CORTRAK 2 EAS specific tube is being used. This gives an additional cost of around £70 to £76 per treatment when CORTRAK 2 EAS is used.

Training is needed to use the system. The manufacturer provides classroom and clinical training at no cost.

No other practical difficulties have been identified in using or adopting the technology.

Likely place in therapy

CORTRAK 2 EAS is used as an adjunctive technology to aid in the blind placement of nasoenteral feeding tubes, or in place of (where used) endoscopic tube placement.

Although the manufacturer indicates that CORTRAK 2 EAS can be used to confirm the placement of nasoenteral tubes and may replace imaging, it states that users should ultimately confirm position according to facility protocol. In standard UK practice, this is aspiration and testing the aspirate using pH paper (and X-ray if necessary) for NG tubes. Initial post-pyloric tube placement is confirmed with an abdominal X-ray, unless placed under fluoroscopic guidance.

Specialist commentator comments

Two specialist commentators highlighted that CORTRAK feeding tubes are considerably more expensive than standard feeding tubes with pH or X-ray confirmation of placement. One commentator noted that procedural costs for the CORTRAK 2 EAS will vary depending on the location in which the device is used and the experience of the operator. The commentator added that using the same CORTRAK 2 EAS in different wards at the same hospital may also affect overall costs, because of the resource use associated with transporting the equipment, implementing appropriate infection control measures, and repairing any damage caused by repeated movement. However, they also stated that there may be additional costs if CORTRAK 2 EAS were used on a single ward, such as those associated with storage space. Finally, the commentator noted that because the system is only compatible with CORTRAK feeding tubes, the impact of an increase in the price of these feeding tubes could be substantial. They suggested, therefore, it would be worthwhile performing a sensitivity analysis to demonstrate the extent to which any financial benefit derived from the system would be affected by an increase in the price of CORTRAK feeding tubes.

One commentator expressed concern at the availability of the anonymous mode, noting that there would be no audit trail from procedures where this mode is used. Another commentator noted that CORTRAK 2 EAS is more likely to benefit trainee clinicians than clinicians experienced in placing feeding tubes.

One commentator surmised that CORTRAK 2 EAS is not necessarily quicker, more reliable in preventing misplacement, or cheaper than standard methods of feeding tube insertion. They added that the exception appears to be cases where its use allows endoscopic feeding tube placement (and the associated cost and unpleasantness) to be avoided, although it was stressed that there are comparatively few of these cases. A second commentator stated that NG tubes are rarely placed with an endoscope. One commentator noted that in a subset of endoscopic tube placements, the endoscopy may be needed for other diagnostic purposes. In these cases, part of the endoscopic cost at the time of feeding tube placement should be attributed to the diagnostic effort.

Two commentators agreed that the benefits of using CORTRAK 2 EAS in addition to facility protocol (pH paper and X-ray) for confirming feeding tube placement are unclear. One commentator noted, however, that if CORTRAK 2 EAS were to reliably replace the need for X-ray tube placement confirmation, then potentially worthwhile savings would arise. According to the commentator, avoiding X-rays could reduce the time between insertion of tube and starting feeding, as well as save the time of nurses and other staff members who may need to accompany patients to X-ray. Another specialist added that although the device may be associated with a reduction in the number of X-rays, these slots are likely to be utilised by other services and, therefore, may not result in meaningful cost savings for a hospital. They added that it is important to note that X-ray costs differ substantially between trusts.

Finally, one commentator stated that from their personal experience, they were unsure how an electromagnetic probe system would be able to demonstrate the location of a feeding tube to the same degree of accuracy as air contrast on plain X-ray, which confirms location almost beyond doubt.

Equality considerations

NICE is committed to promoting equality, eliminating unlawful discrimination and fostering good relations between people with particular protected characteristics and others. In producing guidance and advice, NICE aims to comply fully with all legal obligations to:

  • promote race and disability equality and equality of opportunity between men and women

  • eliminate unlawful discrimination on grounds of race, disability, age, sex, gender reassignment, marriage and civil partnership, pregnancy and maternity (including women post-delivery), sexual orientation, and religion or belief (these are protected characteristics under the Equality Act 2010).

CORTRAK 2 EAS may particularly benefit people with chronic diseases of the nervous system (such as cerebral palsy or multiple sclerosis), which may result in swallowing disorders. Multiple sclerosis is a progressive disease and people with multiple sclerosis are considered to have a disability from the point of diagnosis.

CORTRAK 2 EAS is contraindicated for people with implanted medical devices that may be affected by electromagnetic fields. Certain chronic diseases, such as heart disease, may be treated with implanted medical devices. Chronic disease is treated as a disability if it has a substantial and long-term adverse effect on a person's ability to carry out normal day-to-day activities.

Disability is a protected characteristic defined in the Equality Act 2010.

Patient and carer perspective

The Patients on Intravenous and Naso-gastric Nutrition Treatment (PINNT) support group made the following comments on the device.

Despite guidelines stating that NG tube placement is to be confirmed by aspiration and pH confirmation, many hospitals still use X-ray imaging for confirmation. This can be very distressing for patients because there is usually a long delay between tube placement and X-ray imaging confirmation.

The use of aspirate confirmation can be problematic for some people with low output in the stomach, for whom obtaining a positive aspirate can be a challenge. People with low stomach output would still have to undergo X-ray confirmation.

The nasal cavity can become very sensitive due to tube placement, irrespective of the care used during placement, so any delay in removing the guide wire causes additional discomfort and distress to the patient.

It is important to acknowledge that for many people tube placement is a distressing and upsetting procedure and therefore anything that can minimise the level of discomfort and anxiety that accompanies it is of benefit.

Placement of tubes in certain population can be particularly challenging, particularly people with learning difficulties or special needs. The necessity for quick placement and confirmation is vital for the person and their carer as repeated attempts will lead to further anxiety and distress.

For many people the use of CORTRAK 2 EAS when placing nasoenteral tubes will be of great benefit.