Nasogastric (NG) Tube Insertion – OSCE Guide

Nasogastric (NG) tube insertion is an important skill you’ll be required to demonstrate in your OSCE exams. The procedure requires excellent procedural and communication skills to perform the task effectively whilst reassuring the patient.

Check out the nasogastric tube (NGT) insertion mark scheme here.

If you want to learn more about how to confirm an NG tube is placed safely, check out our guide here.


Wash hands

Introduce yourself

Confirm patient details – name / DOB


Explain procedure

“At the moment you’re having trouble swallowing food in the normal way and therefore we need to place a fine tube through the nose going into the stomach to enable you to receive nutrition in the meantime.”

“The procedure will be uncomfortable, but shouldn’t be painful. It won’t take very long. If at any point it becomes too uncomfortable and you want me to stop,  just let me know. You can tap my arm if you are unable to talk.”


Gain consent – “Are you ok to go ahead with the procedure?”

Insertion of an NG tube is contraindicated in cases of head trauma where there are concerns regarding base of skull fractures compromising the cribriform plate (as the tube could potentially enter the intracranial space).

Gather equipment

  • NG Tubefine bore
  • Disposable gloves
  • Lubricant and gauze – to lubricate NG tube tip
  • Disposable bowl – in the event of vomiting
  • Paper towels – to allow patient to wipe around their mouth if needed
  • Large syringe – to obtain an aspirate
  • pH testing strips – to assess pH of aspirate
  • Tape / dressing to secure NG tube
  • Glass of water for the patient (if swallow is deemed safe)
  • Local anaesthetic spray – if available
  • NG tube equipment
    Gather equipment


1. Position the patient sitting upright with their neck straight

2. Don gloves

3. Measure the desired length of NG tube to be inserted:

  • Measured from the bridge of the nose to the ear lobe
  • Then down to 5cm below the xiphisternum
  • NG tube insertion
    Position the patient sitting upright

Insertion of NG tube

1. Lubricate the tip of the NG tube

2. If available, a local anaesthetic spray can be used on the back of the throat

3. Insert the NG tube in through a nostril – warn the patient prior


4. Gently advance the NG tube through the nasopharynx

  • This is often the most uncomfortable part for the patient, so don’t go too slowly
  • If resistance is met, rotating the NG tube can help, however DO NOT force the NG tube
  • If the patient is becoming distressed or gagging, pause to allow the patient to relax
  • It’s useful to look inside the patient’s mouth intermittently to ensure the NG isn’t coiling in there


5. Continue to advance the NG tube down the oesophagus

  • Ask the patient to take some sips of their water and swallow
  • This can help facilitate the advancement of the NG tube
  • However avoid giving patients a drink if their swallow is deemed unsafe


6. Once you reach the desired insertion length, fix the NG tube to the nose with a dressing

  • NG tube insertion
    Lubricate the tip of the NG tube

Aspiration of NG tube

1. Attempt to aspirate gastric contents:

  • If aspiration is successful, test the pH (if pH is <4 this suggests correct placement)
  • If aspiration is unsuccessful or the pH is >4 the patient will require a chest x-ray (CXR)
  • Some hospitals require a CXR regardless of pH, so check your local guidelines
  • Acceptable pH ranges also vary between hospitals, so consult local guidelines


2. Once NG tube is deemed safe for feeding (or other uses), the guidewire can be removed

3. Dispose of used equipment into a clinical waste bin

4. Wash hands

  • Aspirate NG tube
    Attempt to aspirate gastric contents & assess pH

To complete the procedure

1. Explain to the patient that the procedure is over

2. Reassure that the NG tube will become more comfortable over the next few hours

3. Offer patient paper towels to clean their face and nose


4. Document clearly the procedure of NG tube placement:

  • Your full name and medical grade
  • Procedural details and any complications
  • Aspirate pH (if you were able to aspirate anything)
  • CXR details if used – e.g. NG tube visible dissecting the carina and sitting below the left hemidiaphragm 
  • Outcome – e.g. “SAFE to commence feeding”
  • Your signature, bleep / phone number and registration number

5. Inform nursing staff that the NG tube is inserted and safely positioned


Dr Ally Speight

Consultant Gastroenterologist


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