1. Naso-gastric tube insertion
Mem Van Beek
Clinical Educator
Bradford Teaching Hospitals

2. AIM
To enable the student to understand the principles of safe NG tube use.

3. Objectives By the end of this session students should be able to:
State:
Types of NG tubes & their uses
Indications for insertion
Complications
Legal aspect around NG tube insertion
Insert a naso-gastric tube safely and competently

4. Types of NG tubes Ryle’s tube for gastric drainage
Fine –bore feeding tube
Fine Bore – it is softer more pliable and can rot.
Ryles is made of plastic and is firmer
Feeding
Draining

5. INDICATIONS FINE BORE NG TUBE Short term enteral feeding (4-6 weeks)
Malnutrition
Head & neck surgery
Ca Head & neck / oesophagus
Inadequate intake
Oral cavity fistulae
To prolong & sustain life
If patient requires feeding for more than 4-6 weeks then consider either gastrostomy feeding tube, jejunostomy feeding tube, or an oesophagostomy feeding tube.

6. INDICATIONS cont RYLE NG TUBE To drain gastric contents
Abdominal distension
Unconscious pt
Major surgery
Intestinal obstruction
To stop vomiting & prevent aspiration

7. Contraindications Head injury – basilar skull # Rhinorrhea –CSF
Obstructing oesophageal ca
Epistaxis
Feeding above an obstruction
Recent gastro oesophageal anastomosis
Hx of nasal or sinus surgery
occlusions
Rhinorrhea –CSF from nose after basilar skull fracture

8. Cautions Neck & buccal flap repair Laryngectomy Oesophageal ca
Head & neck surgery
Uncooperative pts

9. Complications of NG feeding
Aspiration
due to feed regurgitation
or incorrect tube placement
Nausea & vomiting
due to rapid feeding
poor gastric emptying
Diarrhoea
Type of feed ie Jevity
Gut infection

10. Complications cont Constipation Blocked tube Unstable BMs
inadequate fluid intake
immobility
use of opiates
Blocked tube
inadequate or no flushing of tube
administering meds via tube
Unstable BMs
↑BMs esp with high carb feed
↓BMs esp if feed is stopped quickly or interupted

11. Complications cont Deranged electrolytes- re feeding syndrome
Fluid overload
Intestinal obstruction
Dislodged tube
Weight loss/ gain
Due to feed imbalances – poor regime
Excoriation of skin around tube
Phosphates, nitrates, Mg2+, K+ levels can be upset esp if pt was malnourished.
Excess protein in feed can cause damage to kidneys, elevating the BUN (Blood Urea Nitrogen)

12. Risks associated with NG tubes
Pneumothorax
Coiling of tube in the throat
Parotiditis
Retropharyngeal Abscess
Sinusitis
Acid reflux
Aspiration pneumonitis
Severe sepsis (the most serious risk)
Pneumothorax 2° tube accidentally entering the larynx & trachea leading to puncture/ rupture of the thin membrane lining the chest wall.
Parotiditis – infection of the parotid glands
Retropharyngeal abscess 2° to perforation of a sinus
Sinusitis - 2° damage to the ciliary epithelium
Aspiration pneumonitis – inflammation of the air sacs - 2° reflux of stomach content
Severe sepsis - 2° incorrect placement of the NG tube into the bronchial tree – can result in death of the pt.

13. Legal Aspect 2005 NPSA – 11 deaths due to misplaced NG feeding tubes
Correct & clear documentation
National & Local guidelines
Clinical Gov & DoH state that feeding tube position should be checked and a risk assessment carried out
On insertion
Before each feed or medication admin
Following vomiting/ coughing/ suction
At least once during continuous feed
If external length of tube changes
If ever there is a concern that tube is not in stomach.

14. Measuring length of feeding tube
From bridge of nose to ear lobe to bottom of xiphisternum
Research by Beckstrand et al (2007) in children showed that age specific methods for predicting the distance to the stomach based on the height of the patient gave highly accurate predictions of the internal distances,
And in the event that age specific methods can’t be used, the measurement from the tip of the nose to the measure midpoint btn tip of xiphoid & the upper edge of the umbilicus was the next best thing.
Infact the nose – ear – xiphoid above was found to give estimates that were either too short or too long for pt, up to 33% of the time.
* It’s not clear if the same results can be applied to adult patients.

15. Position of pt during insertion
Patient should sit in high fowler (upright) with head slightly flexed forward to partially occlude the trachea, preventing the tube from being inserted into the airway.

16. Equipment required Tray Fine bore with introducer / Ryle’s tube
Receiver
Sterile water
Glass of water
20ml syringe
Tape (hypoallergenic)
Lubricating jelly
Indicator strips ( pH fix, 0-6, Fisher scientific)
Cetacaine hydrochloride may also be sprayed towards the back of the pt’s throat before tube insertion to depress the gag reflex.

17. Procedure Clinically clean procedure Wash hands Introduce self
ID patient
Gain informed consent
Arrange a signal of communication
Pt to sit in high Fowler’s position
Prepare equipment
Measure tube (as previously stated) & mark with tape.

18. Procedure Lubricate tube Check for nostril patency
Insert the rounded end of tube into the clearer nostril & slide it backwards & inwards along the floor of the nose to the nasopharynx.
When tube reaches nasopharynx (back of throat), ask pt to sip & swallow some water using a straw.
Advance the tube through the pharynx (as pt continues to swallow) till the predetermined mark has been reached
If at any point pt shows signs of distress/ cyanosis – remove tube.
Lubricate tube – the Fine bore only needs to be placed in a receiver with sterile water and the tube will automatically lubricate its self
- the Ryle’s tube will require a drop of aqua gel to lubricate before insertion
Nostril patency can be checked by asking the patient to close each nostril in turn and sniff with the open one. Use the one that sounds the clearest. If both are the same, just choose any.
If there is some Resistance during insertion, reposition the pt’s head slightly or gently twist the tube as you advance it.

19. Procedure Secure the tube to nostril & cheek with tape
Check the position of the tube to confirm that it is in the stomach by
Check pH
Do X-ray of chest & upper abdomen
NO OTHER METHODS ARE ACCEPTED (NPSA 2005)
If position is correct;
Mark the tube at the exit site & record the tube length in the notes
remove guide wire from fine-bore tube & start feeding per regime
Connect drainage bag to Ryle’s tube for free drainage or spigot for prn aspiration.

20. Checking pH
Flush the NG tube with 20ml of air – to clear any substance already in tube
Aspirate 2ml of stomach content and test on pH strip. (blue litmus paper should not be used)
pH should be ≤5.5 (acidic)
If checking pH in tube already in place, wait 1hour after feed or medication as these can affect pH reading.
If pH of >5.5 is obtained – & pt is asymptomatic send for X-ray
It is also good practice to check the back of the pt’s throat with a pen torch and tongue depressor to see if tube is coiled up in the pharynx especially in patients who struggled to cooperate i.e elderly, very ill.
Remember Any condition that alters the pH in GI tract or tracheobronchial tree will render pH testing unreliable. Examples include
Pt taking antacids or acid-inhibitors
Gastric reflux
Pernicious anaemia
Visceral neuropathy
Never use pH testing in place of CXR which is still the Gold standard.

21. REMEMBER DO NOT use the ‘whoosh’ test DO NOT use blue litmus paper
DO NOT use absence of respiratory distress
DO NOT monitor bubbling at end of tube
DO NOT use appearance of fluid aspirate
‘Whoosh’ test – Auscultation of air insufflated through the feeding tube – a method banned by the NPSA after reports of disastrous results on feeding after confirming tube position using the method
Blue Litmus Paper – tests if aspirate is acidic or alkaline – should not be used because Blue litmus paper is not sensitive enough to distinguish between bronchial and gastric secretions
Observing for signs of respiratory distress is ineffective as tubes can enter the respiratory tract with few if any symptoms especially with fine bore tubes used to feed pts.
Observing for bubbling at the proximal end of the tube is unreliable because the stomach also contains air & could falsely indicate respiratory placement.
Gastric contents can look similar to respiratory secretions so you can not make a judgement based on appearance.
NPSA 2005

22. Document Date Time Type of tube inserted Reason
Length inserted & how it is marked
pH of aspirate
Nursing instructions