Nasogastric Tube Insertion and Placement Checks: A Safe Practice Guide for Nurses

Nasogastric (NG) tubes are used for feeding, giving medicines, and draining the stomach. They are common and look simple, but a tube placed in the lungs instead of the stomach can kill if feed or medicine is given through it. In England, NHS Improvement classes feeding through a misplaced NG tube as a “Never Event”: a serious incident that should be wholly preventable. Safe practice comes down to correct placement checks every time.

Before insertion

• Confirm the indication and prescription, and check for contraindications such as facial fractures, base of skull fracture, recent nasal or oesophageal surgery, or oesophageal varices (seek senior advice).
• Explain and gain consent (or act in best interests if the patient lacks capacity).
• Choose the right tube: fine-bore tubes for feeding; wider-bore tubes for drainage.
• Gather equipment: tube, lubricant, pH indicator strips (CE-marked for human gastric aspirate), enteral (ENFit) syringe, securing tape, glass of water if the patient can swallow, gloves, apron, vomit bowl.

Insertion steps

1. Position the patient upright, head in a neutral position.
2. Measure the tube: from the tip of the nose to the earlobe, then to the xiphisternum (NEX). Note the mark.
3. Lubricate the tip and insert into the clearer nostril, advancing gently along the floor of the nose (backwards, not upwards).
4. When it reaches the back of the throat, ask the patient to swallow (sips of water if safe) while you advance the tube.
5. Stop immediately if the patient coughs persistently, becomes breathless, cyanosed, or cannot speak: the tube may be in the airway. Withdraw it.
6. Advance to the measured mark, then secure the tube and record the external length at the nostril.

Confirming placement

UK patient safety guidance sets out two accepted first-line methods:

1. pH testing of aspirate: draw back aspirate with an enteral syringe and test on a CE-marked pH strip. A pH of 1 to 5.5 indicates gastric placement and it is safe to proceed. A pH above 5.5 is not safe; do not feed and seek advice. Medicines such as antacids and proton pump inhibitors can raise gastric pH.
2. Chest X-ray, interpreted by a competent, trained practitioner, if aspirate cannot be obtained or pH is above 5.5. The interpretation and decision must be documented.

Methods you must NEVER rely on

• The “whoosh” test (auscultation of injected air). It is unreliable and has been linked to deaths.
• Blue litmus paper to test for acidity.
• Looking at the appearance of the aspirate.
• Placing the end of the tube in water to look for bubbles.
• Absence of coughing or distress (tubes can enter the lungs silently, especially in sedated or unconscious patients).

In many hospitals in low-resource settings, the whoosh test is still taught. If pH strips are not available, raise this with your managers: they are inexpensive and save lives.

Re-checking placement

Check placement (pH test, and the external length mark) before every feed, before giving medicines or flushes, at least once a day during continuous feeding, and after vomiting, retching, coughing fits or if the tube appears to have moved.

Feeding and medicines

• Keep the patient at 30–45 degrees during feeding and for 30–60 minutes after, to reduce aspiration risk.
• Use enteral (ENFit) syringes, not IV syringes, to avoid wrong-route errors.
• Flush with water before and after feeds and each medicine.
• Check with a pharmacist before crushing tablets: modified-release and enteric-coated tablets must not be crushed. Use liquid forms where available.
• Give medicines one at a time, flushing between each.
• Watch for diarrhoea, vomiting, abdominal distension and refeeding syndrome in malnourished patients (monitor phosphate, potassium and magnesium).

Documentation

Record the tube type and size, nostril, external length, method of confirming placement, pH result (or X-ray confirmation), and who confirmed it. Document every subsequent check.

Related: Rights of medication administration · Stroke and swallowing · Nursing documentation

Based on NHS England/NHS Improvement patient safety alerts on nasogastric tube placement and the British Association for Parenteral and Enteral Nutrition (BAPEN) guidance. Educational content: follow your local policy and training.