Nutritional support for children and young people: nasogastric tubes

Nutritional support may be required when children and young people (CYP) are unable to independently meet their own nutritional needs. This nutritional support can often be provided through a nasogastric tube (NGT)—a thin plastic tube, inserted through the nose and into the stomach, via the oesophagus (Figure 1). The ability to ‘insert, manage and remove’ NGTs is a standard of proficiency for registered nurses (Nursing and Midwifery Council (NMC), 2018a).

Figure 1. Nasogastric tube location

In 2006, the National Institute for Health and Care Excellence (NICE) published a guideline on nutritional support for adults (NICE, 2006). However, there is no NICE guideline specifically for paediatric patients, instead the only guidance available recommends NGT nutritional support to patients with individual conditions, such as diarrhoea and vomiting or bronchiolitis (NICE, 2009; 2015). The Guidelines and Audit Implementation Network (GAIN) recognised this lack of guidance on NGT use in CYP and published a resource in 2016, which offers useful advice for health professionals regarding NGT use in CYP. It also identifies training needs for patients, parents and/or carers and staff who use NGTs (GAIN, 2016).

Although the use of NGTs in CYP nursing is common, the risk of harm from incorrect placement and management has been a concern for the NHS for many years and has been the focus of a number of National Patient Safety Agency alerts (NPSA, 2005a; NPSA, 2005b; NPSA, 2011a; NPSA, 2012). The NHS has declared that the introduction of fluids into the respiratory tract from a misplaced NGT is a ‘never event’, which would require investigation under the Serious Incident framework if it were to occur (NHS Improvement, 2018).

In 2016, NHS Improvement published a resource set to advise health professionals of the necessary checks for NGT placement. It highlights that, although incorrect placement of an NGT into the respiratory tract will not normally cause the patient any pain or direct harm, the introduction of liquids into the respiratory tract via that NGT could be fatal (NHS Improvement, 2016). It is important for health professionals inserting NGTs to understand that patients who have liquids introduced into the respiratory tract via an incorrectly placed NGT would not usually display signs of coughing or choking, because these reflexes are stimulated by the sensation of fluids at the back of the throat, not lower down in the respiratory tract (NHS Improvement, 2016).

These safety concerns highlight the need for nurses using NGTs with CYP to have a sound understanding of when it is appropriate for an NGT to be inserted and how to manage a patient on an NGT.

There are numerous reasons why CYP may need nutritional support, and this support may not always occur through an NGT. It is important that nurses caring for patients requiring nutritional support are able to understand when an NGT would be appropriate and when other methods should be considered.

Indications

NGTs are usually inserted as a short- or medium-term method of feeding for CYP, as patients who require longer term support would often have a percutaneous endoscopic gastrostomy (PEG) inserted (NHS Improvement, 2016). Although NGTs can also be used for the purposes of aspirating from the stomach and delivery of medications (GAIN, 2016), this article will focus on the use of NGTs solely for nutritional support.

The British Association for Parenteral and Enteral Nutrition (BAPEN, 2012) provides guidance for health professionals on making the decision to insert an NGT. The guidance states that there are a number of contraindications to NGT insertion (Table 1); it identifies that the gastrointestinal tract must be functioning adequately in order to absorb nutrients, or alternatively other feeding methods, such as total parenteral nutrition (TPN), young person with any of the contraindications listed in Table 1, should seek expert specialist advice before inserting an NGT for nutritional support (BAPEN, 2012).

An NGT may be required for nutritional support if a patient is physically unable to swallow; this may be due to a physical condition such as a cerebrovascular accident (stroke) or loss of consciousness from trauma (NHS Improvement, 2016). An NGT may be used in the above conditions for short- or medium-term nutritional support as the patient may recover from this illness. Additionally, the short-term use of NGTs is recommended in conditions such as bronchiolitis, where the patient has a medical condition that affects their ability to take in nutrition orally, although the patient is still able to physically swallow. NGT insertion due to poor feeding is common in infants with bronchiolitis, because infants are often unable to co-ordinate swallowing milk alongside the increased work of breathing caused by the bronchiolitis, without compromising their efficacy of breathing (NICE, 2015). Conversely, long-term conditions such as Duchene muscular dystrophy, where a patient will not regain their swallow, are likely to be better managed through the insertion of a PEG (NHS Improvement, 2016). Table 2 shows the different methods of NGT feeding used in CYP, including the advantages and disadvantages of each method.

The decision to insert an NGT must be made taking into account the wishes of the child or young person and their parent and/or carer, ensuring that consent is gained (NMC, 2018b). Nir et al (2013) demonstrated that parents are often averse to the idea of their child having an NGT inserted. Although oral rehydration is the treatment recommended by NICE (2009) for mild dehydration, Nir et al (2013) found that 75% of parents would refuse an NGT as a treatment option for dehydration. This therefore necessitates that the nurse who is caring for CYP requiring nutritional support is able to justify the recommendation to insert an NGT over other treatment options.

Safety considerations

There are many important safety considerations for CYP with NGTs, which are identified below. Some potential complications associated with NGT feeding are identified in Table 3, alongside strategies to resolve them.

Important practices

Always use pH test paper to test an NGT

To check for gastric placement of an NGT an aspirate should be tested for pH. Blue litmus paper, however, is not sensitive enough to distinguish between bronchial and gastric secretions and so cannot confirm correct placement on its own; therefore, nurses must use pH paper to test the acidity of secretions. Stomach pH is approximately 1-3 when empty and approximately 4-5 after the consumption of food, whereas the pH in healthy lungs is between 7.38 and 7.42.

A pH in the ‘safe range’ of 1-5.5 must be established as the first-line test to exclude placement of the NGT in the respiratory tract. To improve the reliability of test results falling between a pH of 5 and 6, a second competent nurse should independently check the result (NPSA, 2011a). Box 1 identifies when an NGT should be tested.

Box 1.When to test an nasogastric tube in a child or young person

• Following insertion of the nasogastric tube
• Before the administration of each feed
• Before giving medication (If feed is not already in progress)
• At least once a day during continuous feeding and prior to changing syringe feeds in infants and neonates
• Following episodes of vomiting, retching or coughing
• Following evidence of tube displacement (eg visible external tube length is longer/shorter/kinked than previously recorded, loose tapes)

Do not use the ‘whoosh test’

The whoosh test, whereby air is inserted into an NGT while a nurse listens to the chest with a stethoscope, is an unsafe method of determining whether an NGT is correctly positioned in the stomach (NPSA, 2011a). The test is unsafe because it is unable to precisely locate the origin of the ‘whoosh’ sound, due to the proximity of the lungs and stomach.

The absence of respiratory distress is not an indicator of correct positioning

Some children, due to their diagnosis, might not show respiratory distress when they have a misplaced NGT. NGTs can enter the respiratory tract without causing any symptoms and the introduction of fluid through these in any volume can be harmful (NHS Improvement, 2016).

Know the patient's medication/feeding regimen

A child or young person's medication and feeding routine may have an impact on the pH reading. If the patient is receiving medication, which is known to alter pH readings, it is important to identify the patient's unique care requirements in their care plan, to notify those involved in their care.

Do not introduce any type of fluid through the tube until placement is confirmed

pH testing for gastric placement relies on collecting aspirate via the NGT tube; any fluid introduced down the tube before placement is confirmed will contaminate this aspirate, potentially leading to false positive pH readings. Any flush in an NGT could cause aspiration pneumonia if the tube is misplaced in the lungs.

If the NGT will not test

Inability to aspirate an NGT can indicate displacement; however, it is worth considering whether the tip of the NGT is incorrectly placed in relation to gastric contents. Assisting the child or young person to lie on his or her side may allow the tip of the tube to become immersed in gastric contents and facilitate an accurate test (NPSA, 2011b).

If this is unsuccessful, it is recommended to measure the patient (using a new NGT) to establish whether the NGT is of the correct length. Advancing the NGT could help reach any gastric fluid present as the tip of the tube could be sitting in the oesophagus instead of the stomach. Additionally, if the tube is inserted too far, it could be placed in the duodenum where pH values are higher (pH 6-8) and aspiration is more difficult. This can be resolved by withdrawing the tube 10-20cm.

The tip of NGTs can sometimes sit against the gastric mucosa causing occlusion on aspiration. Gently injecting 1-5 ml of air can help clear debris (Newcastle upon Tyne Hospitals NHS Trust, 2017) and move the tube move away to allow aspiration (NPSA, 2005). This technique is not the whoosh test. Caution, however, should be exercised when injecting air into a newly inserted nasogastric tube because this may damage the pleura.

Record every pH test in the patient notes

To assist investigation in the event of respiratory feeding following initial placement of an NGT, an aspirate pH test should be recorded in the patient's notes (NPSA, 2011a).

X-ray can be used to confirm placement

An X-ray on an NGT is required if aspirate in the ‘safe range’ cannot be obtained to verify that the NGT is correctly inserted in the stomach (NPSA, 2011a). However, it is not routine practice due to exposure to radiation.

Therapeutic holding

Young children may need to be ‘swaddled’ during the process of NGT insertion to ensure correct positioning of the patient and ease of insertion. Guidelines for therapeutic holding should be followed in these circumstances and parents/carers can be involved if they are comfortable and able. Play can also be a useful distraction technique and should be used if appropriate (Drape and Greenshields, 2020).

Infection control

It has been demonstrated that poor feed preparation, storage and administration can be causative factors in feed contamination (Best, 2008; NICE, 2012; Malhi, 2017). Using aseptic non-touch technique, effective hand decontamination and the wearing of personal protective equipment (PPE), such as non-sterile gloves and aprons are key infection control measures (Best, 2008; NICE, 2012; GAIN, 2016). Pre-packaged, sterile ready-to-use feeds should be favoured over reconstituted feeds (NICE, 2012). Hang time for ready-to-use feeds is a maximum of 24 hours and no more than 4 hours for reconstituted feeds.

Oral hygiene

If the CYP is not having any oral fluids, then additional oral hygiene maybe required to keep the mouth moist, to prevent gum disease and stimulate saliva and gastric secretions (GAIN, 2016). Tooth brushing should be encouraged twice daily in all patients to ensure optimum oral hygiene (Greenshields, 2019).

Nasogastric tube insertion during the COVID-19 pandemic

NGT insertion is not currently listed as an aerosol generating procedure on Public Health England's (PHE) most recent list of COVID-19 Infection Prevention and Control Guidance: Aerosol Generating Procedures (PHE, 2020a). As such, standard PPE for health professionals inserting NGTs should include gloves, an apron and a fluid-resistant surgical facemask (FRSM Type IIR) as a minimum (PHE, 2020b).

BAPEN (2020) unsuccessfully lobbied for the insertion of NGTs to be recognised as an aerosol-generating procedure with the recommendation that health professionals wear gloves, a full body gown or fluid repellent coveralls, eye or face protection (including full-face visors) and a fluid resistant surgical face mask (FRSM Type IIR), as per PHE's guidance for aerosol-generating procedures (Public Health England, 2020b). However, because PHE does not define NGT insertion as being an aerosol generating procedure, as a minimum, health professionals should ensure that they are appropriately protected with the minimum PPE outlined by PHE guidance while also practising in accordance with their local policies and procedures.

Conclusion

Caring for CYP who require nutritional support through an NGT requires the health professional to have a clear understanding of the benefits and risks of this method of feeding. Liquid, which is introduced to the lungs through a misplaced NGT, could be fatal so it is imperative that health professionals ensure they are proficient in caring for NGTs to prevent this ‘never event’ from occurring.

KEY POINTS

• Nasogastric tubes (NGTs) may be inserted into the stomach as a short- or medium-term method of feeding for children and young people
• Health professionals need to have a clear understanding of the benefits and risks of NGT feeding
• Liquid is introduced to the lungs through a misplaced NGT could be fatal
• Feeding into the lungs via a misplaced NGT is a ‘never event’, according to NHS Improvement (2018)
• Patients who have liquids introduced into the respiratory tract via an incorrectly placed NGT would not usually display signs of coughing or choking, because these reflexes are stimulated by the sensation of fluids at the back of the throat
• Health professionals must use pH test paper to check an NGT before every feed

CPD reflective questions

• What indications for nasogastric tube (NGT) feeding are you likely to come across in your own practice?
• What complications, if any, to NGT feeding have you come across in practice?
• Now that you have read the article, what changes might you consider making in your practice?