Nasogastric Tube

See Also

Indications

Reduces Stomach distention
Reduces risk of aspiration (but does not eliminate aspiration risk)
Prolonged Positive Pressure Ventilation

Precautions

Nasogastric Tube placement can induce Nausea and Vomiting
1. Functional equipment (e.g. yanker suction) for immediate suctioning should be available on NG placement
Thick or semisolid gastric contents will not be suctioned by a Nasogastric Tube (with risk of Emesis)

Contraindications

Cribriform plate Fracture (use Orogastric Tube instead)
Maxillofacial Trauma

Preparation
Tube Size

Size
1. Child: 10-14 French
2. Adult: 14-18 French
NEX Method of estimating length
1. Bridge of nose to earlobe to xyphoid process
2. Note centimeter mark at this point of tube (insertion may be a few cm beyond this point)
Scalzo method of estimating length
1. Nasal Insertion Length: (0.25 x height in cm) + 13

Preparation
Pre-medication

Topical Decongestant (decreases Epistaxis risk)
1. Oxymetazoline (Afrin) 0.05% nasal spray or
2. Phenylephrine (Neo-Synephrine) 0.5% nasal spray
Topical Anesthesia options
1. Lidocaine nasal spray 4% by atomizer
2. Preservative-free Lidocaine 10% by nebulizer
  1. Lidocaine 10% 4 ml (400 mg total)
  2. Nebulize by Face Mask
  3. Do not use if Asthma history
3. Combination 1: Lidocaine jelly, Cetacaine Spray
  1. Lidocaine 2% intranasal jelly
  2. Tetracaine-Benzocaine (Cetacaine) pharyngeal spray
4. Combination 2: Lidocaine atomizer and jelly
  1. Preservative-free Lidocaine 4% by atomizer
    1. Spray 4% once in nostril (1.5 ml)
    2. Spray 4% twice at posterior pharynx (3 ml)
  2. Lidocaine 2% Jelly
    1. Sniff 5 ml Lidocaine into nostril and swallow
5. References
  1. Gallagher (2004) Ann Emerg Med 44:138-41 [PubMed]
Anxiolysis
1. Midazolam 2 mg IV before procedure
  1. Significantly reduces pain with the procedure and eases placement
  2. Although 1 mg was also trialed in age over 60 years old, it was not effective
  3. Manning (2016) Acad Emerg Med 23(7):766-71 +PMID:26990304 [PubMed]

Technique

Don Personal Protective Equipment (gloves, gown, Eye Protection)
Position patient
1. Elevate the patient's head of bed to 45 to 90 degrees
2. Raise bed to appropriate height for the person performing the procedure
3. Identify the patient's most patent nare
4. Drape the patient's chest with an absorbent pad (e.g. chux pad)
Preparation of the tube
1. Select the proper tube size (see above)
2. Estimate the insertion length (see above)
  1. Consider taping the insertion distance on the tube
3. Lubricate the insertion tip of the NG tube (distal 2 to 4 cm)
4. Salem Sump Tube has 2 ports
  1. The shorter, clear port has an adapter for suction
  2. The longer, blue port is an air vent (entrains air and prevents vacuum effect)
    1. Keep the blue tubing above the level of the Stomach to prevent gastric fluid leakage
    2. Anti-reflux valve can be attached to the blue port
Tube insertion
1. Insert the tube into the nare and begin to advance
2. Patient flexes their neck forward as the tube enters the nasopharynx
3. As the tube enters the throat, have the patient attempt to swallow
  1. Consider having the patient take small sips of fluid during this time to facilitate Swallowing
4. Advance the tube carefully but steadily to avoid prolonging patient discomfort
  1. Never force the tube
  2. Consider twisting the tube during insertion
5. Stop the procedure and withdraw the tube if patient begins to cough or tube coils in the back of the throat
Secure the tube
1. Typically apply specific fabric tape over the tip of the nose to anchor the tube
Confirm correct placement
1. Chest XRay
  1. Confirm placement
2. Gastric Tube aspirate pH
  1. pH < 5.5 is an accurate confirmation of proper Gastric Tube placement
3. Auscultate over Stomach while insufflating
  1. Commonly used, but misses most tube misplacements
Resources
1. How To Insert a Nasogastric (NG) Tube | Measurement, Placement & Insertion (Lecturo)
  1. https://www.youtube.com/watch?v=ief6SBTHqrw

Protocol
Discontinuing in Resolving Ileus (Adults)

Instill Milk of Magnesia 3 ounces via NG tube
Clamp Nasogastric Tube for 8 hours
Unclamp tube and aspirate residual Stomach contents
1. Discontinue NG tube if Residual Volume <120 cc
2. Stomach normally secretes several liters in a day
3. Small Residual Volume suggests adeguate drainage

Causes
Blood in gastric aspirate

Upper gastrointestinal Hemorrhage
Oropharyngeal blood (swallowed)
Traumatic insertion
Upper Gastrointestinal Tract injury (from insertion)

Complications
Nasogastric or nasoduodenal Feeding Tubes

General
1. Self-Extubation (common)
2. Increased secretions and need for suctioning
3. Increased need for repositioning
4. Clogged or kinked Feeding Tube
5. Secondary mechanical obstruction from Feeding Tube (pylorus obstruction or Small Bowel Obstruction)
6. Increased Intracranial Pressure (gagging or Vomiting)
  1. Provide adequate anxiolysis and sedation
Nasopharyngeal Trauma
1. Epistaxis
2. Otitis Media
3. Sinusitis
4. Nasopharyngeal erosions
Trachea, Bronchi and lung
1. Post-cricoid perichondritis
2. Misdirected tube into airway (with risk of infusion directly into lung)
3. Tracheoesophageal fistula
4. Pneumothorax
5. Gastric aspiration with secondary pneumonitis
6. Lung Abscess
7. Tracheobronchial perforation
8. Airway obstruction
Esophagus
1. Esophageal bleeding
2. Esophageal or duodenal perforation
3. Esophageal Stricture
4. Esophagitis or Esophageal Reflux
5. Rupture of Esophageal Varices

References