Nasogastric (NG) Tube Insertion

by | Sep 11, 2024 | Nurse Article | 0 comments

Nasogastric (NG) Tube Insertion – Correct insertion techniques, verifying tube placement, troubleshooting blockages, and preventing aspiration.

Nasogastric (NG) Tube Insertion

Nasogastric (NG) tube insertion is a common procedure used for feeding, medication administration, or gastric decompression. Proper insertion techniques, verification of tube placement, troubleshooting blockages, and preventing aspiration are crucial for patient safety and comfort.

1. Correct Insertion Technique

a. Indications for NG Tube Insertion

  • Nutritional support (for patients unable to eat by mouth).
  • Gastric decompression (to remove stomach contents in patients with bowel obstruction or post-surgery).
  • Administration of medications or fluids when oral intake is not possible.

b. Equipment

  • NG tube (appropriate size, usually 12-16 French for adults).
  • Water-soluble lubricant.
  • Glass of water with straw (if patient is able to swallow).
  • 60 mL syringe (for air insufflation or aspiration).
  • pH paper (for gastric content testing).
  • Stethoscope.
  • Tape or tube securement device.
  • Gloves and protective equipment (gown, mask).
  • Suction setup (if decompression is needed).

c. Steps for NG Tube Insertion

  1. Explain the Procedure: Inform the patient about the steps involved, the purpose of the NG tube, and potential discomfort during insertion.
  2. Patient Positioning:
    • The patient should be in a high Fowler’s position (sitting up at 45-90 degrees) to minimize the risk of aspiration.
    • The head should be slightly extended, and once the tube is advanced past the throat, the patient’s chin should be tilted toward the chest to facilitate passage into the esophagus.
  3. Measure the Tube:
    • Measure the tube from the tip of the patient’s nose to the earlobe and then from the earlobe to the xiphoid process (bottom of the sternum).
    • Mark this length with a piece of tape or a marker.
  4. Lubricate the Tube:
    • Apply water-soluble lubricant to the first 4-6 inches of the tube.
  5. Insert the Tube:
    • Insert the tube gently through the nostril and direct it downward toward the throat.
    • Ask the patient to swallow (if possible) as the tube reaches the throat. Sips of water may help with this.
    • Advance the tube to the pre-measured length. If resistance is met, withdraw the tube slightly and attempt to insert again. Do not force the tube.
  6. Secure the Tube:
    • Once the tube is fully inserted, secure it to the patient’s nose with tape or a tube holder to prevent dislodgement.

2. Verifying Tube Placement

Ensuring the NG tube is in the stomach and not the lungs is critical to prevent complications such as aspiration pneumonia.

a. Methods to Verify Placement:

  1. Aspirating Stomach Contents:
    • Attach a syringe to the tube and gently aspirate stomach contents.
    • Test the pH of the aspirate. A pH of 1-5.5 generally indicates gastric placement.
  2. Air Insufflation (Whoosh Test):
    • Inject 10-20 mL of air into the NG tube using a syringe while listening over the stomach with a stethoscope.
    • A “whooshing” sound in the stomach indicates correct placement. However, this method is less reliable and should be used with caution.
  3. Chest X-ray:
    • A chest X-ray is the gold standard for confirming NG tube placement, especially in cases where there is uncertainty.
  4. Observing for Signs of Misplacement:
    • If the patient coughs persistently, experiences respiratory distress, or if the tube does not advance easily, these may be signs of improper placement in the airway. The tube should be removed immediately, and placement should be reassessed.

3. Troubleshooting Blockages

NG tubes may become blocked due to thick feedings, medications, or dried secretions.

a. Steps to Address Blockages:

  1. Flush the Tube:
    • Flush the NG tube with 30-60 mL of warm water before and after feedings or medication administration to prevent blockages.
  2. Use a Syringe:
    • Attach a 60 mL syringe and gently attempt to aspirate the blockage or push water through the tube to dislodge it.
  3. Enzymatic or Bicarbonate Solutions:
    • If the tube remains blocked, enzymatic agents or sodium bicarbonate solutions may be used to dissolve blockages caused by medications.
  4. Replace the Tube:
    • If blockage persists and cannot be cleared, the NG tube may need to be replaced.

4. Preventing Aspiration

Aspiration is a serious complication of NG tube feeding and can lead to aspiration pneumonia. Proper precautions should be taken to prevent this.

a. Prevention Techniques:

  1. Elevate the Head of the Bed:
    • Keep the head of the bed elevated at 30-45 degrees during feeding and for at least 30-60 minutes after feeding. This reduces the risk of gastric contents flowing into the esophagus and being aspirated.
  2. Check Gastric Residual Volume:
    • Before each feeding, check the gastric residual volume (GRV) by aspirating stomach contents.
    • A high GRV (usually >200 mL) may indicate delayed gastric emptying and an increased risk of aspiration. In such cases, feeding should be held or slowed down, and the patient’s clinical status reassessed.
  3. Monitor for Coughing or Gagging:
    • Persistent coughing or gagging during feeding can be a sign that the NG tube is misplaced or that the patient is at risk of aspiration.
  4. Use Small, Frequent Feedings:
    • Providing smaller, more frequent feedings instead of large volumes can reduce the risk of aspiration, especially in patients with compromised swallowing or delayed gastric emptying.
  5. Verify Tube Placement Regularly:
    • Check tube placement regularly, especially before feedings, using pH testing or auscultation, to ensure it remains in the stomach.

Summary of Key Points:

  • Insertion Technique: Measure and insert the NG tube carefully, allowing the patient to swallow to aid in tube advancement.
  • Verification of Placement: Use a combination of aspirating stomach contents, air insufflation, and confirm with a chest X-ray if needed.
  • Troubleshooting Blockages: Flush the tube regularly, and if blockages occur, attempt to clear them with warm water or enzymatic solutions.
  • Preventing Aspiration: Keep the head of the bed elevated, check gastric residual volumes, and monitor the patient for signs of aspiration during and after feeding.

By following these guidelines, NG tube insertion and management can be performed safely and effectively, minimizing complications and ensuring patient comfort.