Nasogastric Tubes
Aim of the session
To demonstrate nasogastric tube insertion and explain how to care for patients with Ryles
tubes and feeding tubes.
Learning Objectives
For students to be able to:
Identify the equipment required.
Demonstrate how to pass a nasogastric tube on a manikin.
Explain how to test pH.
Discuss the possible complications associated with nasogastric tube feeding.
What is a Nasogastric Tube?
A Nasogastric tube is inserted through the nose and oesophagus into the stomach to either
remove gastric contents or deliver feed.
Contraindications
Never insert a nasogastric tube on a patient with nasal obstruction or severe head and
facial injuries if there is risk of basal skull fracture or causing further damage.
Cautions
Use caution in recent surgery on the face, oesophagus or stomach.
Upper gastrointestinal surgery with an anastomosis
Gastric stasis, reflux, stricture, nasal injuries and gastric varicies and coagulopathy.
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Types of tubes
Wide-bore Ryles tubes are used to remove gastric contents and relieve distension, nausea
and vomiting for example in bowel obstruction or surgery.
FG 10 to 16 are available but 14/16 are most suitable for aspiration of gastric content. They
can be used to administer short term feed however if not also needed for aspiration a
feeding tube should be used.
Narrow-bore feeding tubes with guide wires are used to feed for a period of up to 6 weeks
to deliver nutritional support when the GI tract is functioning or long-term nutritional support
when PEG tube insertion is not appropriate.
Feeding tubes are made of polyurethane and have a narrow bore usually FG 08 for adult’s
length 110cm and FG 06/08 for paediatrics length 58cm.
Potential risks
The National Patient Safety Agency (NPSA) reported 11 deaths in 2 years due to
misplaced tubes. There is a risk that the tube can be misplaced into the lungs during
insertion, or move out of the stomach at a later stage leading to aspiration.
Ensure you always test the position, document that you have tested and what the pH was.
Always test the pH prior to feeding or administering drugs and document the result.
Ensure the patient is next to oxygen and suction in case of vomiting or aspiration.
Patients who are comatose, have swallowing difficulties or recurrent vomiting are at risk of
the tube moving.
In comatose patients on ITU the tube is inserted using a laryngoscope.
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Enteral Feeding
Enteral feeding is delivery of nutritional products directly into the gut via a tube. The tube
can be placed into the stomach, duodenum or jejunum via the nose, mouth or
percutaneous route.
Nasoduodenal or nasojejunal tubes bypass problems of gastric reflux or delayed gastric
emptying and risk of aspiration.
Gastrostomy feeding involves placement of a tube through the abdominal wall directly into
the stomach (inserted endoscopically, radiologically or surgically). It is used for patients
who can not tolerate a nasogastric tube.
Jejunostomy tubes create a stoma tract between the jejunum and the abdominal surface
(inserted endoscopically, radiologically or surgically) it is used for patients requiring post
pyloric feeding following major GI, hepatobiliary surgery and severe gastro-oesophageal
reflux if gastric feeding has failed.
Feeding via a nasogastric tube
Used when a patient’s gut is functioning but they are unable to meet nutritional
requirements by diet alone and they are at risk of malnutrition.
Common reasons for feeding include:
The unconscious patient
Neuromuscular swallowing disorder i.e. MS, CVA
Physiological anorexia i.e. cancer, sepsis, liver disease
Upper GI obstruction i.e. stricture or tumour
GI dysfunction i.e. inflammatory bowel disease,
Increased nutritional requirements i.e. burns
Psychological problems i.e. anorexia
Specific treatment i.e. short term access during head and neck surgery
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Mental health i.e. people with dementia
Tubes need frequent flushes with water to avoid blockages because they are narrow and
the commercially prepared feeds delivered can adhere to the wall of the tube. Patients may
also need to be given additional water via the tube to maintain fluid balance.
Patient’s fluid balance and weight should be monitored while they are being fed and it is
crucial that mouth care is not neglected.
Administering feeds
There are a number of different methods that can be used for feeding including using a
pump to deliver feed, bolus feeding by delivering a specified amount of feed slowly by
syringe at regular intervals during the day and gravity feeding.
The hospital dieticians will assess each patient and prescribe an individual regime. Out of
hours an emergency regime will be used.
Prescribing and administering medication
Administration of medicines via an enteral feeding tube is an unlicensed use of these
medicines in the UK.
If a patient is able to swallow or have the medication administered via an alternative route
this is the preferred option.
If there is no alternative route then prescription and administration of medication via an
enteral tube should be in line with the BAPEN (2003) guidelines.
Medication should be reviewed before administration to ensure they are available in a
format that is suitable for administration via the tube.
The medication must be prescribed for NG route not oral.
Tube position must be checked prior to administration of any medication.
The tube should be flushed at the start and end of administration with 50mls water.
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The tube should be flushed between medications with 20mls of water.
Drug administration must be clearly documented.
Blocked Tubes
If a tube is blocked it should be flushed with water, if this does not work warm water, if this
does not work carbonated water, if this fails remove and replace the tube. A 50ml syringe
should be used to avoid exerting excessive pressure on the tube.
Equipment required for nasogastric tube insertion
Apron
Gloves
Alcohol rub
Vomit bowl
Glass of water
Nasogastric tube
Lubricating jelly or water
Drainage bag
NG plaster or tape
50ml purple syringe
Ph testing strips
Tissues
Important first steps
If using a Ryles tube place it in the fridge for 30 minutes before use to make it rigid and
easier to use, this is not necessary for a feeding tube because of the guide wire.
Obtain informed consent – nasogastric tube insertion is unpleasant and the patient needs
to understand what you will be doing and why.
Wash your hands
Risk assess your patient
Assist the patient to sit upright if possible (unconscious patients should be supine, chin in
line with sternum)
Draw the curtains and maintain patient dignity
Check nostrils are patent
Reassure the patient
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The procedure
Wash hands and put apron on and clean trolley
Gather necessary equipment and take trolley to the patient
Open equipment onto the top of the trolley
Alcohol gel hands and put gloves on
Estimate length of tube to be inserted by measuring from the ear to the nose and from the
nose to the xiphisternum and then mark the tube.
Ask the patient to blow their nose
Lubricate the nasogastric tube with lubricating jelly or normasol
Give the patient a glass of water and vomit bowl
Insert the tube into the nostril guiding it gently downwards over the nasopharynx
Encourage the patient to take sips of water and advance the tube as the patient drinks.
This aids swallowing, suppresses vomiting and avoids hyper-extension of neck.
Insert the tube to the point marked at the start of the procedure and secure to the nose (for
feeding tubes the guide wire will need to be removed if an x-ray is not being performed
once the tube is in place).
Check tube position and attach drainage bag
Mark the tube at the exit point in case it moves
Document the procedure and evidence of correct placement
Checking tube position
Following insertion check the tube position using pH paper.
Always confirm tube position using pH paper immediately prior to any feeds.
Aspirate 1-10mls of stomach contents using a 50ml purple syringe
Test the contents on pH paper a reading below 5.5 indicates an acid reaction and means
that the tube is in the stomach.
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Be aware that patients on antacid medication are more likely to have pH levels of 6 and
above and milk can also increase the pH value obtained.
If you are unable to obtain any aspirate turn the patient on their side or ask them to take a
drink and then try again.
Commencing nasogastric feeds
Obtain informed consent
Wash hands, put on apron and gloves
Position the patient at a 30 degree angle to reduce the risk of aspiration
Flush 10ml air into the tube to remove water/feed and aspirate fluid from the stomach
Put a 1 – 10mls of aspirate on the pH strip and match with the colour code on the box
(below 5.5)
If unable to obtain aspirate change position or offer a drink and try again
Do not commence feed until pH reading is below 5.5
Check the feed is prescribed, correct type, within date and that you have the correct
patient.
Attach the administration set to the bottle of feed and run the feed through the line to prime
it (change set every 24 hours)
Put the administration set in the pump and programme the rate and volume to be delivered
Flush the nasogastric tube with 50mls of sterile/tap water before and after each feed (10mls
for paediatric patients).
Attach the administration set to the nasogastric tube and commence the feed
Document procedure and make patient comfortable
Wash hands and dispose of waste
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Refeeding Syndrome
Refeeding syndrome occurs when malnourished patients undergo refeeding the symptoms
include muscular weakness, cardiac insufficiency, convulsion, coma and death.
It is characterised by severe fluid and electrolyte shifts, which have metabolic
consequences such as:
 Hypophosphataemia
 Hypokalaemia
 Hypomagneseaemia
 Altered glucose metabolism
 Fluid balance abnormalities
 Vitamin deficiency
In starvation, insulin concentration decreases and glucagons levels rise. This results in
glucose being produced from the breakdown of protein and fat. Fatty acids and ketones
replace glucose as the major source of energy. In the starved state the breakdown and
utilisation of fat and muscle leads to loss of lean body mass, water and minerals.
During refeeding there is a switch in metabolism from fat back to carbohydrate. As a
consequence insulin is released, which stimulates the uptake of glucose into the cells and
promotes protein synthesis. As glucose is taken into the cells so are phosphorus,
potassium and magnesium and this leads to an extracellular depletion.
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Patients at risk of Refeeding syndrome include:
1. Chronic alcoholics
2. Chronic malnutrition
3. Anorexia nervosa
4. Classic maramus (protein/energy malnutrition)
5. Patients unfed for 7-10 days with evidence of stress and depletion (e.g. muscle
wasting)
6. Hyperglycaemia (e.g. diabetic patients)
7. Chronic antacid users – these bind the minerals, thereby causing low levels.
8. Chronic diuretic users
9. Patients receiving chemotherapy
10. Patients with chronic diseases (e.g. COPD or CRF)
If the patient is at risk of refeeding syndrome the following should be checked for:
K+
<2.5mmol/l
PO4-
<0.5mmol/l
Mg2+
<0.5mmol/l
If these are present they should be corrected before feeding commences.
All patients at risk should be prescribed:
100mg oral thiamine or 1 pair of IV High Potency vitamin B and C (Pabrinex) Ampoules
administered over 10 minutes, half hour before feed commences for 3 days.
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References
BAPEN (2003) Administering drugs via enteral feeding tubes. A practical guide. London: BAPEN
Best C (2005) Caring for the patient with a nasogastric tube. Nursing Standard. 20, 3, 59-65
Earley T (2005) Using pH testing to confirm nasogastric tube position. Nursing Times.101, 38.
Halstead, E. (2009) Enteral Feeding Guidelines. George Eliot Hospital NHS Trust: Nuneaton
National Patient Safety Agency (2005) Reducing the harm caused by misplaced nasogastric feeding tubes.
Alert. www.npsa.nhs.uk
National Institute for Health and Clinical Excellence (2006) Nutrition support in adults. London: NICE.
Naysmith MR, Nicholson J. (1998) Nasogastric drug administration. Prof Nurse; 13, 424-7.
Pearce, C., Duncan, H. ( 2002) Enteral feeding. Nasogastric. Naso-jejunal, percutaneous endoscopic
gastrostomy or jejunostomy. Its indications and limitations. Postgraduate Medical Journal; 78; 918, 198-204.
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Confirming the position of NG enteral feeding tubes
1.
2.
3.
4.
Check if on acid inhibiting medication
Check for signs of tube displacement and measure tube length
Reposition or re-pass tube if required
Aspirate using 50ml syringe and gentle suction
Aspirate not obtained
aspirate
obtained
DO NOT FEED
1. If possible, turn onto one side
2. Inject 1-5ml (infants and children)/10-20ml(adults) air
into the tube using syringe
3. Wait for 15-30 minutes
4. Try aspirating again
Aspirate
obtained
Aspirate not obtained
DO NOT FEED
1. Advance the tube by 1-2cm
(infants and children)/10-20cm
(adults) as tube may only be in
the oesophagus.
2. Try aspirating again
Aspirate
obtained
Aspirate not obtained
Test on pH strip or paper
pH >5.5
pH <5.5
DO NOT FEED
1. Leave for up to one hour
2. Try aspirating again
NOTE. If not on any acid reducing medication it may be
necessary to withdraw the tube by 5 – 10cm (adults) if
aspirate has been obtained and re test aspirate.
Proceed to feed
pH >5.5
DO NOT FEED
1. Call for advice
Ph
2. >5.5
Consider replacement / re-passing of tube and / or
checking position by X-ray
The following methods MUST NOT be used:
 Auscultation of air insufflated through the feeding tube ('whoosh
test')
 Testing acidity / alkalinity of aspirate using blue litmus paper
 Interpreting absence of respiratory distress as an indicator of
correct positioning
 Monitor bubbling at the end of the tube
 Observing appearance of feeding tube aspirate
pH<5.5
Additional tip
If the patient is alert, has an intact swallow
and is perhaps on supplementary feeding
and is thus eating and drinking during the
day, ask them to sip a coloured drink e.g.
diluted blackcurrant cordial and aspirate
the tube. If you get the coloured fluid back
then you know the tube is in the stomach
Caution - if there is any query about position and / or the clarity of the
colour change on the pH strip then feeding should not commence
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ADULT EMERGENCY NG/PEG ENTERAL FEEDING REGIME
NO
Is patient at risk of refeeding syndrome?
(see overleaf)
Flush tube with 50ml water and then
commence feed of nutrison multifibre
at 30ml/hour for 6 hours.
YES
Doctors to:
 Check K+, Mg2+, PO4 levels daily and
supplement as required.
 Prescribe oral thiamine 200mg daily to
be given 30minutes before starting feed.
 Prescribe paediatric seravit od (20g for
women, 25g for men.
Increase rate to nutrison multifibre at
50ml/hour for 14 hours rest for 4 hours.
Flush tube with 50ml water and then commence
feed of nutrison multifibre at 20ml/hour for 20
hours with 4 hours rest.
This provides only 500ml fluid therefore
additional IV fluid/ NG flushes will be required.
Day 1 provides approx 1000ml fluid
therefore patient will require extra fluid via
IV/NG flushes to prevent dehydration.
YES
NO
Are K+, Mg2+, PO4 levels low today?
Doctors to review results
and supplement as
required.
Provide nutrison multifibre at 75ml/hour
over 20 hours with 4 hours rest period.
Continue with this regime until patient
is reviewed by Dietitian.
Provide nutrison multifibre at 35ml/hour over
20 hours with 4 hours rest period.
This provides 700ml fluid therefore additional
IV fluids/NG flushes will be required.
Continue with this regime until patient is
reviewed by Dietitian.




Key points
Ensure tube position is confirmed before using tube.
Flush tube with at least 50ml tap water pre and post each feed and each medication given via
NG tube.
Ensure patients head and shoulders are elevated to at least 30 degrees during and 1 hour post
feeding to reduce aspiration risk.
Only increase feed rate if patient tolerated the previous rate.
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NASOGASTRIC FEEDING REGIMEN
Name……………………………………………………………………… Ward…………………….………………..……………………
CHECKLIST
1.
2.
3.
4.
5.
6.
7.
DATE
Wash hands.
Check tube position with pH paper. pH 5.5 or less indicates gastric placement.
Flush tube with …….. of freshly drawn tap water before and after feed.
Flush tube with …….. of freshly drawn tap water before, after and between medications.
Do not hang feed for more than 24 hours.
Change giving set every 24 hours.
Patient MUST be elevated to at least 30º whilst feed is in progress.
FEED TYPE
VOLUME
RATE
Signed…………………………………………………………………...(Dietitian)
HOURS
Contact ……………….. Dietitian on
ext. or bleep . . . . . if you have any
queries.
COMMENTS
Date………………………………
Administering drugs
Is the drug prescribed via the NG/PEG route?
May wish to consider alternative routes of administration
Is there a commercially available liquid preparation?
Yes
Is the sorbitol content and osmolarity of the liquid
suitable for PEG/NG administration, are there no
known interactions/incompatibilities with feed
Yes
No
No
Yes
Use liquid
Is there a commercially available
soluble/dispersible tablet
No
Can the tablet be dispersed
No
Is the drug
available in
tablet form
Do not crush if: Enteric coated, slow/modified release
Seek pharmacy advice if
Cytotoxic, Hormone, Prostaglandin analogue
No
Yes
Can the capsule contents
be flushed down the tube
with water or other
specific dilutents
Can the tablet be crushed
Is the drug
available in
capsule
form
No
Yes
Is it a hard gelatin capsule
that can be opened
No
No
No
Can capsule
contents be
removed with
syringe & needle
No Can the pharmacy prepare a solution/suspension
No
Can the injection be used
No
Consider alternative drug
Naysmith &
Nicholson 1998
ADULT FEED TYPES AND ALTERNATIVES
All the feeds below are not suitable for use in children under 6 years of age.
Feed Type
Description
Nutritionally
complete in
Alternative feed
Nutritison
Multifibre
Whole protein feed 1kcal/ml with
1.5g/100ml fibre.
Gluten and lactose free
Whole protein feed 1kcal/ml. Gluten,
lactose and fibre free.
Whole protein feed 1.5kcal/ml with
1.5g/100ml fibre. Gluten and lactose
free
Whole protein feed 1.5kcal/ml. Gluten,
lactose and fibre free
Whole protein feed 1kcal/ml with
2g/100ml fibre. Gluten and lactose free
1500ml
Nutrison Standard
1500ml
Nutrison multifibre
1000ml
Nutrison energy
1000ml
Nutrison
energy
multifibre
Nutrison Multifibre
Whole protein feed 1.2kcal/ml with
2g/100ml fibre. Gluten and lactose free
1000ml
Nutrison
1000
complete multifibre
Whole protein feed 1.25kcal/ml with
1.5g/100ml fibre. Gluten and lactose
free
Whole protein feed 1.25kcal/ml.
Gluten, lactose and fibre free
Whole protein feed 2kcal/ml. Reduced
electrolyte/fluid provision. Gluten and
lactose free.
Whole protein feed 1kcal/ml. Reduced
sodium content. Gluten and lactose
free.
1200ml
Nutrison Protein Plus
1200ml
Nutrison Protein Plus
Multifibre
Nutrison Energy
Low fat semi-elemental (pre-digested)
feed based on short chain peptides that
are readily absorbed 1kcal/ml. This
feed is mainly used for malabsorption
or maldigestion conditions. Gluten
free.
1kcal/ml feed for those intolerant to
cow’s milk protein. Gluten, lactose and
milk protein free.
As above, also contains 1.5g/100ml
fibre.
1kcal/ml MCT rich feed, for use in fat
malabsorption/ maldigestion. Gluten
and lactose free.
1500ml
Nutrison Standard
Nutrison Energy
multifibre
Nutrison energy
Nutrison
1000
Complete
Multifibre
Nutrison
1200
Complete
Multifibre
Nutrison Protein
Plus Multifibre
Nutrison Protein
Plus
Nutrison
Concentrated
Nutrison
Sodium
Low
Peptisorb
Nutrison Soya
Nutrison
Soya
Multifibre
Nutrison MCT
1000ml
750ml
1500ml
Nutrison
Standard
(will increase Na input
by
3.2mmol/100mlplease discuss with
doctor)
NO REPLACEMENT
1500ml
Nutrison
Multifibre
Soya
1500ml
Nutrison Soya
1500ml
NO REPLACEMENT
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