Print Friendly, PDF & Email

Common nasogastric (NG) tube exam questions for medical finals, OSCEs and MRCP PACES



What three prerequisites for use of a nasogastric tube to feed are stipulated by NICE guidelines?

Malnourished or at risk of malnutrition; inadequate or unsafe oral intake; functional and accessible gastrointestinal tract.


What are the absolute contraindications to nasogastric tube placement?

Mid-face trauma and recent nasal surgery.


Name two possible complications of nasogastric tube placement.

Any two of gagging/vomiting; tissue trauma including nasal haemorrhage and oesophageal perforation; respiratory tree intubation leading to aspiration.


What are the landmarks for measuring the length of nasogastric tube needed to reach a patient's stomach?

Bridge of nose to earlobe to xiphisternum – usually approximately 55-65cm in an adult.

When should you stop advancing the nasogastric tube? (5 circumstances)
On reaching the measured distance; if the tube emerges in the oral cavity; if the patient experiences respiratory distress or inability to speak; nasal haemorrhage; significant resistance.

How can you confirm placement of the nasogastric tube?

Clinically, with pH testing of apirated fluid from the nasogastric tube – stomach contents have a pH of 0-5. If this is not possible or if the patient takes PPI medication or has had gastric surgery, chest radiograph is required.


What should you document in the patient's notes after insertion of a nasogastric tube?

Consent to procedure, size and length of tube inserted, any complications during insertion, volume and pH testing of fluid if successfully aspirated, need for chest radiograph if not.

What landmarks can you use on a chest radiograph to confirm correct placement of a nasogastric tube?

Bifurcation of the carina in the midline, travel past the diaphragm with subsequent deviation to the left, and a visible tube tip (radiographically) or suitable distance at the nasal tip (clinically) to suggest tube is in the stomach.

If used for feeding purposes, what is the maximum length of time a nasogastric tube should be left in situ?

NICE guidelines recommend using enteral tube feeding for no more than 4 weeks.