Nasogastric Tube Feeding in Older Patients: A Review of Current Practice and Challenges Faced

Table 1

Summary of the various techniques that have been explored (✔pros, ✖cons).

Novel strategies to enable “real-time” confirmation of nasogastric placement
Ultrasound	An alternative technique for live imaging is through ultrasound (US). The feeding tube can also be visualised at the gastrooesophageal junction with longitudinal and angled US scans of the epigastrium. Various studies support the use of US [54].; ✔ Reduced delay in administering enteral nutrition; ✖ Requiring appropriately trained individuals; ✖Availability of US scanners; ✖Lack of studies looking at adverse events [55]
Electromagnetic placement devices	CORTRAK 2 enteral access system has received FDA approval. The nasogastric catheter has an electromagnetic coil at the end. As the tube is advanced, a receiver unit placed externally along the xiphoid process captures electromagnetic signalling and converts it into a 3-dimensional image of the tube tip relative to the diaphragm. This is displayed on a monitor.; ✔Comparable accuracy in confirming NG positioning compared to X-ray [56,57]; ✔Reduced delay in administering enteral nutrition; ✔Real-time visualisation shown to reduce misplacement [52]; ✖ Real-world data has highlighted the risk of pulmonary complications. The FDA issued an alert regarding 51 medical device reports about pneumothorax related events, including 11 patient deaths between 2012 and 2017; ✖ The majority of adverse events are due to misinterpretation of tracings by the operator highlighting the expertise and skill required for this device; ✖ Estimated additional cost of £70-£76 per treatment session. Thus, it has not been approved by NICE, unless there is evidence that it obviates the need for X-rays and pH testing.
Integrated real-time imaging system (IRIS) technology	The kangaroo feeding tube (Covidien Commercial ltd.) has an IRIS in the form of a 3 mm camera attached to the end of the feeding tube, which allows direct visualisation of anatomical landmarks. It has received FDA approval and is currently authorised for research use in the UK. A prospective study on 21 patients in a neurological ITU showed that 90% of patients were successfully intubated, and correct placement was confirmed in all, using abdominal X-ray with contrast [58]; ✔Real-time tracking; ✔ Scope for the camera to verify placement regularly, prior to enteral feeding, and reduce the need for check X-rays.; ✖ It is anticipated that outcomes will be operator-driven, but the training expertise required needs to be evaluated.; Further studies are needed to ascertain safety, accuracy, cost-efficiency, and camera visualisation performance and endurance.
Magnetic technology	A small magnet at the distal end of the nasogastric tube can be used to drag its placement infradiaphragmatically and through the transpyloric sphincter, using an external magnet.; Successful transpyloric placement has been demonstrated; ✖ Does not enable real-time localisation; ✖ Hand-held external magnets can be difficult to use in a ward environment with other magnetic sources contraindicated in patients with implantable cardiac devices
Passive magnetic localisation technology using magnetic sensors	The magnetic tip can be traced by the use of stationary electric sensors positioned externally on the body. An experimental study used a cervical device embedded with magnetic sensors to differentiate the trajectory of the nasogastric catheters in the cervical oesophagus from the trachea, ex vivo [59]. Improved sensitivity of magnetic sensors and improved cost-efficiency provide favourable incentive to develop this technology further