NG Tube Placement Summary

Indications

  • Feeding for malnutrition risk
  • Medication delivery
  • Gastric decompression
  • GI bleeding assessment
  • Toxic material aspiration

Contraindications

  • Basal skull fractures
  • Unstable cervical injuries
  • Nasal/pharyngeal obstruction
  • Esophageal abnormalities
  • Bleeding varices
  • Coagulation disorders

Complications

  • Bronchial placement
  • Pleural space placement
  • Intracranial insertion
  • Nasal trauma
  • Perforation
  • Variceal bleeding

Measurement

  • Nose to earlobe
  • Then to 5cm below xiphisternum

Placement Confirmation

  • pH testing (0-5.5 safe range)
  • Chest X-ray verification
  • Observe for signs of distress

Procedure Tips

  • Upright position with neutral head
  • Lubricate tube tip
  • Advance during swallowing
  • Rotate if resistance met
  • Check for coiling in mouth

Nasogastric Tube Placement

Comprehensive guide to NG tube insertion, confirmation, and management

Indications

Feeding Purposes

  • In people who are malnourished or at risk of malnutrition
  • Inadequate or unsafe oral intake with functional, accessible gastrointestinal tract
  • Examples: stroke, coma, pre- or post-gastrointestinal surgery

Medication Delivery

  • NG tubes can deliver certain medications directly into the stomach
  • Same stipulations as for feeding

Removal of Gastric Content

  • Initial and continued gastric decompression in intubated patients
  • Symptom relief and bowel rest in bowel obstruction
  • Aspiration of toxic material

Diagnostic Uses

  • Assessment of presence or volume of upper gastrointestinal bleeding
  • Administration of radiographic contrast

Contraindications

Healthcare professionals will have varying levels of experience in placing nasogastric tubes therefore some contraindications are relative. Advice should be sought and consideration should be made of the following, which is not an exhaustive list:

Absolute Contraindications

  • Basal skull fractures
  • Unstable cervical spinal injuries
  • Choanal atresia
  • Tracheoesophageal fistula
  • Actively bleeding oesophageal or gastric varices

Relative Contraindications

  • Nasal/pharyngeal/oesophageal obstruction or ulceration
  • Oesophageal/pharyngeal pouch
  • Oesophageal stricture or other abnormalities
  • Oesophageal or oropharyngeal tumors or surgery
  • Post laryngectomy
  • Gastric outflow obstruction
  • Intestinal obstruction
  • Clotting disorders

Complications

The patient should be fully assessed to identify any history of previous nasal fractures, surgery, polyps or other blockages which may complicate nasogastric tube insertion.

Insertion Complications

  • Bronchial placement
  • Pleural space placement
  • Intracranial insertion
  • Gastro-oesophageal junction placement of the tip
  • Nasal trauma
  • Pharyngeal or oesophageal pouch perforation
  • Precipitation of variceal bleeding

Post-Insertion Complications

  • Sinusitis
  • Tube dislodgement
  • Tube obstruction
  • Mucosal erosion
  • Aspiration
  • Reflux esophagitis

Procedure

Step-by-Step Procedure
  1. Position the patient sitting upright with their head in a neutral position
  2. Estimate how far the NG tube will need to be inserted by measuring from the bridge of the nose to the ear lobe and then down to 5 cm below the xiphisternum
  3. If available, a local anaesthetic should be sprayed towards the back of the patient's throat
  4. Lubricate the tip of the NG tube, insert the NG tube through one of the patient's nostrils and advance posteriorly along the floor of the nose to the nasopharynx
  5. Gently advance the NG tube through the nasopharynx; if resistance is met, rotating the NG tube can aid insertion
  6. Intermittently inspect the patient's mouth to ensure the NG tube isn't coiling within the oral cavity and if any resistance is felt throughout passage of tube, do not force the tube
  7. Continue to advance the NG tube down the oesophagus, you can ask the patient to take some sips of water (if safe) and then swallow as this can facilitate the advancement of the NG tube
  8. Once you reach the desired nasogastric tube insertion length, fix the NG tube to the nose with a dressing
  9. Throughout passage of the nasogastric tube the patient should be observed for signs of distress, coughing, cyanosis, gasping etc - any of these may indicate malposition of tube and the tube should be withdrawn
  10. Once the NG tube is deemed safe for use, the radiopaque guidewire can be removed
NG TUBE PLACEMENT DIAGRAM

Proper measurement and placement technique for nasogastric tube insertion

Confirming NG Tube Placement

When inserting an NG tube for feeding and/or administration of medication you need to confirm the safe placement of the tube prior to its use. The incorrect placement of an NG tube can result in life-threatening complications (e.g. aspiration pneumonia).

The position of the nasogastric tube tip must be confirmed prior to use by a competent practitioner and the method of confirmation documented.

Testing pH of NG Aspirate

Confirmation of safe NG tube placement can be achieved by testing the pH of NG tube aspirate. Gastric content has a low pH (1.5-3.5) whereas respiratory tract secretions have a much higher pH. This difference makes it possible to confidently confirm the safe placement of an NG tube using pH testing alone if the pH is within a safe range (typically 0 – 5.5).

Limitations of pH Testing

Confirming Position Using a Chest X-ray

To confirm an NG tube is positioned safely, all of the following criteria should be met:

An NG tube can be positioned in the left or right main bronchus but to still appear in the midline. An NG tube can curl up on itself, meaning the tip is placed higher than it should be which can result in reflux and aspiration of NG tube contents. This demonstrates the importance of confirming you can see the NG tube tip clearly.