Indications
- Gastric decompression (bowel obstruction, ileus, before/after some surgical procedures).
- Enteral feeding or medication administration where oral intake is unsafe or insufficient.
- Administration of activated charcoal or removal of gastric contents in selected poisoning presentations, per toxicology advice.
Contraindications & cautions
Avoid nasal route
- Suspected base-of-skull or significant mid-face fracture — risk of intracranial passage. Use the orogastric route instead.
- Severe facial trauma or recent nasal/skull-base surgery.
Caution
- Known oesophageal varices, strictures, or recent upper GI/oesophageal surgery — discuss with seniors/gastroenterology first.
- Reduced conscious level or absent gag/cough reflex — aspiration risk during insertion.
Measurement and insertion
NEX measurement
Estimate insertion length using the NEX method: tip of Nose → Earlobe → Xiphisternum, marking the tube at this length as a starting estimate (actual insertion is often slightly longer).
Position the patient
Sit upright where possible, neck slightly flexed ("sniffing" or chin-to-chest position) to help the tube pass into the oesophagus rather than the trachea.
Lubricate and insert
Lubricate the tube, pass along the floor of the nose (aiming backward, not upward), and advance steadily.
Encourage swallowing
If the patient can safely swallow, offer small sips of water as the tube passes the oropharynx — swallowing helps the tube pass into the oesophagus rather than the airway.
Watch for respiratory distress
Coughing, choking, cyanosis or inability to speak suggests tracheal passage — withdraw and reattempt.
Secure the tube
Once at the marked length, secure to the nose/cheek, and confirm position before any use.
Position confirmation is safety-critical
- First line — pH testing: aspirate fluid from the tube and test with pH indicator strips. A pH of 1–5.5 reliably indicates gastric placement and the tube may be used.
- If no aspirate is obtained, or pH is outside this range, do not use the tube — reposition, wait, or move to second-line confirmation.
- Second line — chest X-ray, interpreted by a clinician competent in NG position assessment. Confirm the tube: follows the oesophagus in the midline, does not follow the contours of a bronchus, bisects the carina, crosses the diaphragm in the midline, and has its tip clearly visible below the diaphragm.
- Never rely on the "whoosh test" (auscultating air insufflation) or visual/absence-of-cough assessment alone — these are not reliable and must not be used to confirm placement.
- Nothing — feed, water, or medication — goes down the tube until placement is confirmed and documented.
- Re-confirm position after vomiting, retching, forceful coughing, or any sign the tube may have moved, and before each feed/medication round per local policy.
Documentation
- Indication, contraindication screen, NEX measurement, insertion length at the nose, any difficulty/complications.
- pH result (and value), X-ray result if used and who reviewed it, and explicit sign-off that the tube is safe to use.
- Ongoing re-confirmation checks per local policy.
Supervision pointers
Generic ED skills entrustment levels — not a named curriculum DOPS:
| 1 | Observed only — describes contraindications and both confirmation methods. |
| 2a | Performs insertion with supervisor present; correctly measures NEX and obtains a valid pH result. |
| 2b | Performs with supervisor in department; manages difficult passage and interprets confirmation results correctly. |
| 3 | Indirect supervision; recognises when to escalate for X-ray confirmation or specialist placement. |
| 4 | Independent; teaches position-confirmation safety and audits practice. |
References
- NHS Improvement. Patient Safety Alert NHS/PSA/RE/2016/006 — Nasogastric tube misplacement: continuing risk of death and severe harm.
- National Patient Safety Agency. Patient Safety Alert NPSA/2011/PSA002 — Reducing the harm caused by misplaced nasogastric feeding tubes.
- X-ray checks of NG tube position: a case for guided tube placement. Br J Radiol 2021;94(1124):20210432.
- NHS England — Never Events list and framework.