🩺 Nasogastric Tube Placement

Nasogastric (NG) tube placement involves passing a flexible tube through the nasal passage, into the oesophagus, and into the stomach. It is crucial for providing nutrition, administering medication, or decompressing the stomach in bowel obstruction. Because of the risk of inadvertent pulmonary placement, strict safety protocols must be followed to confirm the tip's location before use. pH testing of gastric aspirate is the primary bedside check, with radiography as the definitive secondary check.

Enteral nutrition for patients with a functioning GI tract but inadequate oral intake (e.g., stroke, dysphagia, or critical illness). Decompression of the stomach in cases of intestinal obstruction or ileum. Administration of medications in patients who are 'nil by mouth'. Management of upper GI bleeding to clear the stomach for endoscopy or to assess the rate of bleeding (though less common now). Warm gastric lavage in severe hypothermia.

Suspected or confirmed base of skull fracture (risk of intracranial insertion). Oesophageal varices or recent oesophageal banding (relative, requires senior input). Severe facial or nasal trauma. Known oesophageal strictures or recent upper GI surgery (especially oesophagectomy). If a patient has a total laryngectomy, NG tubes should only be placed by specialists or via the surgical stoma if appropriate.

Fine-bore or wide-bore NG tube (size dependent on indication: feeding vs. decompression). pH indicator paper (must be CE marked and for human use). 60ml catheter-tip syringe. Lubricant (water-soluble). Securement device or hypoallergenic tape. Cup of water (if patient is safe to swallow). Personal protective equipment and a 'Never Event' checklist. Bowl for emesis and a pen torch.

Confirm patient identity and explain the procedure, ensuring a 'Never Event' checklist is ready. Position the patient upright (high-Fowler's). Measure the required length using the NEX method and mark the tube. Lubricate the tip of the tube and gently insert through a nostril, following the nasal floor. Pass the tube back and down; when the patient gags, encourage swallowing (or sips of water) to advance the tube. Advance until the mark is reached at the nostril. Secure the tube to the nose. Aspirate gastric contents using a 60ml syringe and test on pH paper. If pH is ≤5.5, the tube is safe. If pH is >5.5 or no aspirate is obtained, follow local protocols for X-ray confirmation.

The gold standard for confirmation is a pH of aspirate between 1 and 5.5, indicating gastric acidity. If the pH is 6 or above, the tube cannot be used for feeding and requires a chest X-ray for confirmation. X-rays must show the tube following the midline, bisecting the carina, crossing the diaphragm, and the tip sitting below the left hemidiaphragm (ideally 10cm beyond the gastro-oesophageal junction). If the tube follows the line of a bronchus, it must be removed immediately. If no aspirate can be obtained, reposition the patient or inject a small volume of air and try again.

Assuming the 'whoosh' test (auscultating the epigastrium while injecting air) is a reliable confirmation of placement; this is obsolete and dangerous. Testing the pH of an aspirate that was recently contaminated by medication or recent enteral feeding, which may falsely elevate the pH. Not advancing the tube far enough, resulting in the tip sitting in the oesophagus, which poses a significant aspiration risk. Advancing the tube against resistance, which can cause trauma or lead to intracranial placement in cases of unrecognised skull base fractures.

Explain the procedure clearly, warning that it will be uncomfortable and may cause gagging. Measure the tube accurately from the tip of the nose, to the earlobe, then down to the xiphisternum (NEX measurement). If the patient starts coughing, becomes cyanosed, or loses their voice during insertion, remove the tube immediately as it likely entered the trachea. Ask the patient to take small sips of water or 'mimic swallowing' as the tube passes the oropharynx to help guide it into the oesophagus. Always check the pH before anything is administered, and document this clearly in the notes.

Aligned with MLA 'Clinical Skills' (Procedural): Nasogastric tube insertion. This procedure is heavily audited due to 'Never Events' associated with misplacement into the lungs. Students must understand the NPSA (National Patient Safety Agency) safety framework, including the hierarchy of confirmation tests. Knowledge of the NEX (Nose-Ear-Xiphoid) measurement method is fundamental for the MLA.