Chapter 22. Nasotracheal Intubation

Nasotracheal intubation is a relatively simple procedure that is performed rapidly without the aid or risks of neuromuscular blockade.1 This method of intubation is sometimes favored in difficult airway cases, especially when oral access is limited or impossible. Such conditions include trismus, oral injuries, and obstructive oral processes such as angioedema. Nasotracheal intubation is also the method of intubation preferred by some authors for acute epiglottitis.2

Nasotracheal intubation is well tolerated by most patients and produces less reflex salivation than orotracheal intubation, thus leading to fewer attempts at self-extubation. The nasotracheal tube is more easily stabilized and is generally easier to care for than an orotracheal tube. This method prevents biting of the tube by the patient and manipulation by the patient's tongue.2,3

Nasotracheal intubation is indicated in any patient with spontaneous respirations, especially those whose period of intubation is anticipated to be brief.1–3 It is indicated in patients who are unable to lie supine due to respiratory distress from severe asthma, chronic obstructive pulmonary disease (COPD), or congestive heart failure. It is also indicated in patients who are unable to open their mouths due to facial trauma, mandibular trauma, or trismus. Nasotracheal intubation can be performed in patients with limited airway patency due to obstruction from neoplasm or tongue swelling. Nasotracheal intubation is an appropriate method of intubation in patients who require neck immobilization for suspected cervical spine injuries as well as patients who are unable to move their necks due to cervical kyphosis, severe arthritis, or postradiation fibrosis. Because they are often intubated for a short time, patients with severe alcohol intoxication or drug overdose whose level of consciousness is decreased are good candidates for nasotracheal intubation.1–3 Nasotracheal intubation may be performed in patients who have contraindications to the use of succinylcholine (Table 11-2).

Nasotracheal intubation is contraindicated in patients with apnea, severe facial or maxillofacial fractures, basilar skull fractures, head injury with an elevated intracranial pressure, recent nasal surgery, nasal or nasopharyngeal obstruction (nasal polyps), patients receiving thrombolytics or parenteral anticoagulants, and in the presence of a coagulopathy.1–3

Nasotracheal intubation should not be performed in neonates, infants, or very young children. The more anterior and cephalic position of the airway in these age groups makes blind passage of an endotracheal (ET) tube almost impossible. A patient must provide a degree of cooperation during the procedure. A crying, kicking, and struggling child who must be restrained is not a candidate for nasotracheal intubation.

• Nasal mucosa vasoconstrictor (4% cocaine, 0.05% oxymetazoline, or 0.25% phenylephrine)
• Nasal mucosa anesthetic (viscous lidocaine, cocaine, benzocaine spray, or xylocaine spray)
• Nasopharyngeal airways, multiple sizes
• Laryngoscope handle
• Laryngoscope blades, various sizes and types
• ET tubes, various sizes (avg female 7.0–7.5 and avg male 7.5–8.0)
• Endotrol tubes, various sizes (Mallinckrodt Medical, St. Louis, MO)
• Magill forceps
• Suction apparatus
• Topical anesthetic (4% cocaine or 2% lidocaine with epinephrine)
• Gauze strips
• Water-soluble lubricant or anesthetic jelly
• Bag-valve device
• Face mask
• Oxygen source and tubing

Explain the risks, benefits, and potential complications of the procedure to the patient and/or their representative if time permits. All procedural steps should be clearly outlined, with the understanding that an orotracheal intubation may be necessary should the Emergency Physician fail to secure the airway nasotracheally. Since this is a lifesaving procedure, a signed consent may not be necessary, but a procedure note should be included in the medical record.

Prepare the patient with preoxygenation, hemodynamic monitoring, pulse oximetry, and intravenous access. Place the patient supine and in the “sniffing” position if there is no suspicion of a cervical spine injury. If the patient needs to remain sitting due to respiratory distress, also place them in the sniffing position.

Examine the patient's nostrils. Choose the larger and more patent nostril for the intubation. The choice of the nostril to use is not an exact science.11 Look into each nostril and determine which one is more patent. Estimate the airflow through each nostril. Occlude one nostril and instruct the patient to exhale with their mouth closed. Repeat the process with the other nostril. Ask the patient which nostril they feel is more patent. This test can be repeated after the application of a vasoconstrictor agent. There is no evidence suggesting one nostril is better than the other (i.e., left vs. right) for intubation in a patient with normal anatomy.

Prepare the mucous membranes. Apply a topical vasoconstrictor to shrink the nasal mucosa followed by a topical anesthetic to the nasal mucosa. Cocaine is preferred if not contraindicated, because it is a single agent that acts as both a vasoconstrictor and an anesthetic. Dilate the nasal passage by serial dilation. Liberally lubricate a series of increasingly larger-size nasopharyngeal airways. Insert and then remove the smallest nasopharyngeal airway. Continue to insert and remove each successively larger nasopharyngeal airway until the nasal passage is dilated. This procedure can take 2 to 3 minutes. If time is an issue, insert a gloved and lubricated pinky finger into the nostril to dilate it. For routine nasotracheal intubations of healthy adults, serial dilation of the nasal passages can be bypassed in patients with large nostrils.6 Next, apply a topical anesthetic spray to the palate and oropharynx.

Choose an ET tube. The proper size tube should be at least 0.5 to 1.0 mm smaller than the size chosen for orotracheal intubation of the same patient. If possible, soften the ET tube by placing it in warm saline or warm water before use to reduce epistaxis and nasal damage.7 Apply a 10 mL syringe to the inflation port and inflate the cuff. Check the integrity of the cuff. Deflate the cuff and leave the syringe attached. Lubricate the ET tube.

Blind Placement of an ET Tube

The technique of blind nasotracheal intubation was first described by Magill in 1930. The technique essentially remains the same with some modifications to increase the success rate and limit complications. This technique is technically more difficult than the placement under direct vision described below. Its major advantages are that the patient's mouth does not have to be opened and minimal to no cervical spine movement is required. This procedure may be performed while the patient is sitting or supine. Prepare the patient as mentioned previously.

Stand to the right side of the patient's bed and facing them. Insert the ET tube into the nostril with the bevel facing the septum (Figures 22-1 and 22-2A). If the patient's right nostril is being used, insert the ET tube concave side down (Figure 22-1A). If the patient's left nostril is being used, insert the ET tube concave side up (Figure 22-1B). Advance the ET tube with gentle pressure along the nasal floor to pass it through the nasal cavity (Figure 22-2B). If any resistance is felt, slightly withdraw the ET tube. Readvance the tube with a slight twisting motion to bypass the obstruction. If resistance is still met, withdraw the ET tube, prepare the other nostril, and insert the tube into the other nostril.

When the ET tube is inserted approximately 5 to 7 cm, the tip will be past the choana and in the nasopharynx (Figure 22-2B). Continue advancing the ET tube as resistance is met while the tube makes a 90° change of direction into the oropharynx. A slight twisting motion may be required to advance the ET tube. A loss of resistance signifies that the ET tube has made the curve. Stop advancing the ET tube and rotate it so that the tube's natural curve is concave upward and in the same curvature of the airway. If the ET tube will not curve from the nasopharynx into the oropharynx, several options are available. These include trying the other nostril, using an ET tube 0.5 mm smaller and reattempting intubation through the original nostril, or using an Endotrol tube (described in the next section).

Advance the ET tube through the oropharynx and into the laryngopharynx (Figure 22-2C). Listen for breath sounds through the proximal end of the ET tube while advancing it. The breath sounds and air movement will be maximal when the tip of the ET tube is just above the glottis. As soon as an exhalation is heard, the patient will take a breath and advance the ET tube. The vocal cords are opened their widest during inspiration, and this will facilitate passage of the ET tube.

The patient will often cough or gag as the ET tube traverses the vocal cords. At this point, breath sounds should be audible from the proximal end of the ET tube and it should fog with each breath. If the patient is able to groan or speak, the esophagus has been intubated. Withdraw the ET tube and reinsert it during inspiration. The application of posteriorly applied pressure on the trachea (Sellick's maneuver) will occlude the esophagus and may allow easier ET intubation.

If resistance to the advancement of the ET tube is felt, it may be caught in the hypopharynx. Common sites for the tip of the ET tube to get caught are the arytenoid cartilage, piriform sinus, vallecula, and the vocal cords. Withdraw the ET tube 3 to 4 cm, slightly rotate the ET tube, and readvance it.

Inflate the ET tube cuff. Confirmation of ET tube placement should be assessed by auscultating both lungs while ventilating the patient with a bag-valve device through the nasotracheal tube. Adjust the position of the tube until both lungs are being ventilated equally and secure the tube (Figure 22-2D). Continue to ventilate the patient.

Blind Placement of the Endotrol Tube

The indications, contraindications, and patient preparation are the same as described above. The Endotrol tube is an ET tube whose tip can be controlled. It looks like a cuffed ET tube but has a plastic ligature along the inner side that is connected to a ring on the proximal end of the ET tube (Figure 22-3). Pulling of the ring exerts tension on the plastic ligature, leading to an increase in the curvature of the tip of the ET tube. This will project the tip anteriorly and inferiorly (Figure 22-4). The procedure for inserting the Endotrol tube is the same as that for inserting an ET tube. Changing the curvature of the tip will aid in passage of the tube from the nasopharynx to the oropharynx and from the hypopharynx into the trachea. If the ring is sitting firmly against the nares after intubation, the tip of the tube may be exerting continuous pressure on the anterior tracheal mucosa. Cut the ligature and remove the ring.

Placement under Direct Vision

The technique begins with nasotracheal intubation, followed by direct laryngoscopy. The placement of a nasotracheal tube using direct visualization must be performed with the patient supine. The indications and precautions are similar to those for orotracheal intubation (Chapter 11). This method should be considered in the event of an oral injury that renders an orotracheal tube a nuisance or if blind nasal intubation is unsuccessful.

This procedure is initially performed as previously described. Once the tube is inserted into the hypopharynx, direct laryngoscopy is performed. Using the left hand, grasp the laryngoscope and insert the blade. Visualize the patient's epiglottis and vocal cords as well as the ET tube. Using a Magill forceps with the right hand, grasp the ET tube just above the cuff (Figure 22-5). Never grasp the cuff, as it is delicate and can easily be damaged by the Magill forceps. Have an assistant grasp the proximal end of the ET tube and gently advance it while the physician simultaneously guides the tip through the vocal cords (Figure 22-5). Remove the Magill forceps and the laryngoscope. Inflate the cuff, secure the tube, and ventilate the patient.

Blind Digital Nasotracheal Intubation

A technique was developed that combines blind nasotracheal intubation and digital orotracheal intubation.12 This technique starts with the procedure of blind nasotracheal intubation. If not successful, insert the index and middle fingers of the nondominant hand into the patient's mouth. Slide these fingers posteriorly over the tongue to palpate the epiglottis. Grasp the tip of the ET tube between the two fingers (Figure 22-6A). Pull the ET tube anteriorly and behind the epiglottis (Figure 22-6A). Use the nondominant hand to advance the ET tube further into the patient's nose, thus advancing the tip into the trachea (Figure 22-6B).

The position of the ET tube should be confirmed by end-tidal CO2 monitoring, fogging in the ET tube for at least six ventilations, loss of voice, auscultation over the chest and the epigastrium, and a chest X-ray. Please refer to Chapter 12 for a more detailed discussion regarding confirmation of endotracheal intubation.

The ongoing care of the patient should proceed as with any other intubation technique.

The immediate complications of nasotracheal intubation include epistaxis, laryngeal and tracheal trauma, mucosal avulsion, retropharyngeal laceration, turbinate avulsion, intracranial placement, bacteremia, esophageal intubation, and prolonged attempts to place the tube.4,5 Many of these can be prevented by choosing the appropriate size ET tube, ensuring adequate nasal mucosal vasoconstriction, and applying a liberal amount of lubricant to the ET tube. Risk factors for epistaxis should be assessed on every patient prior to nasotracheal intubation.8 Long-term complications include maxillary sinusitis, retropharyngeal abscess, mediastinitis, nasal mucosal necrosis, and cellulitis.4,5

Very little literature is available regarding nasotracheal intubation on children. In the past, this approach was an option for patients with epiglottitis and acute laryngotracheobronchitis.9 The most recent data reserve nasotracheal intubation for children with congenital facial anomalies.10 This technique cannot be recommended for children in the Emergency Department. Their small nostrils limit ET tube size. Large adenoids may make passage of the ET tube difficult and increases the risk of bleeding.

Nasotracheal intubation is an alternative to orotracheal intubation to secure an airway in the spontaneously breathing patient. It allows awake intubations while the patient maintains protective airway reflexes, and it avoids the risks of paralytic agents. It is a fairly simple procedure that should be considered in patients in whom an oral airway is considered difficult and in those with an anticipated short intubation period.