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HLT-RESP80-05 · Lesson 7 · 28 clock hours · lab

Nasotracheal Intubation and Tube Management

Objective. Students will perform blind nasotracheal intubation on an airway trainer and correctly secure an endotracheal tube, measure and record cuff pressure within the accepted therapeutic range, and identify signs of tube displacement.

⚠ Pending professional review

This lesson, its worked examples and its practice questions has not yet been verified by a licensed clinician in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it to make decisions about any patient or medication. Always follow your instructor, your supervising professional, and current official references and regulations.

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Nasotracheal Intubation and Tube Management

Overview

Nasotracheal intubation (NTI) is a technique for placing an endotracheal tube (ETT) through the nostril, along the nasopharynx, through the glottis, and into the trachea. It is most often used when oral access is limited — for example, in patients with trismus, cervical spine precautions, or facial trauma — and in spontaneously breathing patients where the blind technique is feasible. As a respiratory therapist you are responsible not only for tube placement but also for ongoing tube management: securing the airway, monitoring cuff pressure, and recognizing displacement promptly.

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Anatomy Relevant to NTI

The nasal passage is lined with highly vascular mucosa. Trauma during intubation can cause significant bleeding. The right nostril is typically preferred because it offers a straighter path toward the glottis, though either nostril may be used. The tube passes through the nasopharynx, past the epiglottis, and between the vocal cords into the trachea. Correct depth places the distal tip 3–5 cm above the carina.

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Blind NTI Technique

In the blind technique, breath sounds guide tube advancement. Spontaneous breathing is essential — the patient must be moving air for this method to work safely.

1. Prepare the patient. Explain the procedure. Pre-oxygenate as clinically indicated. Apply topical vasoconstrictor and anesthetic to the nasal mucosa per institutional protocol to reduce bleeding and discomfort.

2. Select tube size. For adults, a tube smaller than used orally is typical; consult current references for size ranges, as patient anatomy varies.

3. Lubricate the tube. Use a water-soluble lubricant on the distal portion of the tube.

4. Insert through the nostril. Direct the tube perpendicular to the face (not upward) along the floor of the nasal cavity, advancing gently to avoid turbinate trauma.

5. Listen for breath sounds. Hold the proximal end of the tube near your ear or use a device designed for this purpose. As the tip approaches the glottis, breath sounds become louder and more turbulent.

6. Advance on inspiration. The cords open widest during inspiration. Time the advancement so the tube enters the trachea as the patient inhales. A sudden increase then muffling of sounds and resistance often signals entry through the cords.

7. Confirm placement. Use capnography (end-tidal CO₂ detection) as the primary confirmation method. Also auscultate bilaterally at the lung bases and apices, and observe chest rise. Absence of sounds over the epigastrium supports tracheal — not esophageal — placement.

8. Note depth. Record the centimeter marking at the nostril once correct placement is confirmed.

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Securing the Endotracheal Tube

An unsecured or poorly secured tube is a patient safety hazard. Two common methods are:

After securing, re-verify the centimeter marking at the nostril and document it. Bite blocks or oral airways may be needed for orally intubated patients to prevent biting; they are generally unnecessary for nasal routes.

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Cuff Pressure Management

The ETT cuff seals the airway to allow positive-pressure ventilation and reduce aspiration of oral secretions. Both under-inflation and over-inflation cause harm.

Current evidence-based guidelines recommend maintaining cuff pressure within a range that provides an adequate seal while preserving mucosal perfusion. The generally accepted therapeutic range is 20–30 cmH₂O. Measure cuff pressure with a calibrated aneroid manometer (cuff manometer) at regular intervals and after any position change or suspected leak. Document every measurement.

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Identifying Tube Displacement

Three common displacement problems require immediate recognition and action:

Right mainstem intubation: The tube is advanced too far and enters the right main bronchus. Findings: diminished or absent breath sounds on the left, decreased oxygen saturation, asymmetric chest rise. Action: deflate cuff, withdraw tube slowly while auscultating until bilateral breath sounds are equal, re-inflate cuff and re-confirm depth.

Accidental extubation: The tube is no longer in the trachea. Findings: sudden loss of waveform on capnography, no chest rise, patient phonating, severe desaturation. Action: remove the tube, provide manual ventilation with bag-mask device, and reintubate when the patient is stabilized.

Cuff leak: Air escapes around the cuff. Findings: audible gurgling or hissing, lower delivered tidal volumes, patient may phonate around the tube, cuff pressure below target. Action: add air to the cuff and remeasure pressure; if the cuff will not hold pressure, prepare for tube exchange.

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Safety Reminders

Key terms8

Blind nasotracheal intubation (NTI)Placement of an endotracheal tube through the nostril and into the trachea without direct visualization of the glottis, using breath sounds to guide timing of advancement.
Cuff pressureThe pressure inside the inflatable balloon (cuff) of an endotracheal tube, measured in cmH₂O; the accepted therapeutic range is 20–30 cmH₂O.
Cuff manometerA calibrated handheld gauge used to measure and adjust endotracheal or tracheostomy tube cuff pressure.
Right mainstem intubationA form of tube displacement in which the ETT tip has advanced into the right main bronchus, ventilating only the right lung and causing absent or diminished breath sounds on the left.
CapnographyContinuous measurement and waveform display of exhaled carbon dioxide; the primary method for confirming and monitoring endotracheal tube placement.
TracheomalaciaWeakening and collapse of the tracheal wall cartilage, a potential long-term complication of sustained excessive ETT cuff pressure.
Vasoconstrictor (topical)A medication applied to the nasal mucosa before NTI to constrict blood vessels and reduce the risk of bleeding during tube passage.
Accidental extubationUnplanned removal of the endotracheal tube from the trachea, a life-threatening emergency requiring immediate bag-mask ventilation and reintubation.

Worked examples3

1. After securing an ETT following nasotracheal intubation, you connect the cuff manometer and read 36 cmH₂O. What action is needed, and how much pressure must be removed to reach the midpoint of the therapeutic range?
  1. Identify the accepted therapeutic range: 20–30 cmH₂O.
  2. Calculate the midpoint of the range: (20 + 30) ÷ 2 = 25 cmH₂O.
  3. Determine the excess pressure: 36 − 25 = 11 cmH₂O above the midpoint target.
  4. Action: slowly release air from the cuff using the manometer until the gauge reads 25 cmH₂O, then verify the seal by checking for air leak around the cuff during a ventilator breath.
Answer: Remove 11 cmH₂O of pressure to reach the midpoint of 25 cmH₂O. Current pressure of 36 cmH₂O exceeds the safe upper limit and risks tracheal mucosal ischemia.
2. You measure cuff pressure at 14 cmH₂O. The patient is on a ventilator and you hear an audible gurgle around the tube on each breath. How far below the minimum acceptable pressure are you, and what are two clinical consequences of leaving this uncorrected?
  1. Identify the minimum acceptable cuff pressure: 20 cmH₂O.
  2. Calculate the deficit: 20 − 14 = 6 cmH₂O below the minimum.
  3. Identify clinical consequence 1: Inadequate seal allows ventilator gas to escape, reducing delivered tidal volume and potentially causing hypoventilation.
  4. Identify clinical consequence 2: The gap between the cuff and tracheal wall allows oral and pharyngeal secretions to migrate past the cuff, increasing aspiration risk.
Answer: Cuff pressure is 6 cmH₂O below the minimum. Add air until the manometer reads 20–30 cmH₂O. Consequences of under-inflation include inadequate ventilation and increased aspiration risk.
3. A patient is nasally intubated with the tube secured at 26 cm at the right nostril. After repositioning the patient to the left lateral decubitus position, you re-check and find the tube is now at 23 cm at the nostril, oxygen saturation is dropping, and there are no breath sounds on the left. What has occurred and what is the corrective depth adjustment needed to return to the original position?
  1. Compare the current depth (23 cm) with the original secured depth (26 cm): the tube has advanced 3 cm deeper.
  2. A tube advanced too far in an adult typically enters the right mainstem bronchus, explaining absent left-sided breath sounds.
  3. Needed adjustment: withdraw the tube 3 cm (from 23 cm back to 26 cm at the nostril) to restore the original position.
  4. After withdrawing, deflate cuff slightly during withdrawal if resistance is felt, then re-inflate, re-confirm bilateral breath sounds, recheck cuff pressure, and re-secure the tube.
Answer: Right mainstem intubation has occurred. Withdraw the tube 3 cm to return to the 26 cm mark, then confirm bilateral breath sounds and re-secure.
In class: Demonstrate nasotracheal intubation technique on the adult airway trainer using breath-sound guidance to time tube advancement, repeating until consistent technique is achieved. · Practice endotracheal tube securing using both tape and a commercial tube holder; measure cuff pressure with a manometer after each attempt and record whether pressure falls within the acceptable range per current evidence-based guidelines. · Work through three written displacement scenarios — right main-stem intubation, accidental extubation, cuff leak — and write the assessment findings and corrective actions for each.
Materials: Adult airway trainer, nasotracheal tubes in multiple sizes, commercial tube holder, adhesive tape, cuff pressure manometer, stethoscope, gloves, lubricant, displacement scenario worksheets
Check: Skills checklist: student advances tube on breath sounds, secures tube without critical error, and records cuff pressure within the accepted therapeutic range on two observed attempts; pass = zero critical errors.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

Patient Assessment and Disease Management
1. During blind nasotracheal intubation, at which phase of the respiratory cycle should the tube be advanced through the vocal cords?
Therapeutic Procedures
2. What is the accepted therapeutic range for endotracheal tube cuff pressure?
Emergency and Critical Care
3. A ventilated patient suddenly shows absence of a capnography waveform, no chest wall rise, audible phonation, and rapidly falling SpO₂. The most likely cause is:
Therapeutic Procedures
4. After nasotracheal intubation, auscultation reveals diminished breath sounds over the left lung and the SpO₂ is declining. The tube is at 32 cm at the nostril. What is the most appropriate immediate action?
Patient Assessment and Disease Management
5. Which finding is the gold standard for confirming endotracheal tube placement in the trachea?
Patient Assessment and Disease Management
6. A patient's ETT cuff manometer reads 38 cmH₂O on two consecutive checks. The most serious long-term risk of leaving this uncorrected is:
Therapeutic Procedures
7. When inserting a nasotracheal tube through the nasal passage, the therapist meets firm resistance before the tube reaches the nasopharynx. The correct response is to:
Emergency and Critical Care
8. A patient has an audible gurgle on each ventilator breath, and the measured cuff pressure is 12 cmH₂O. After adding air to the cuff, the manometer will not maintain pressure above 10 cmH₂O despite repeated attempts. The most appropriate next action is to:
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