Equipment
Equipment required for nasotracheal intubation includes the following:
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Endotracheal tube - Nasal RAE (Ring-Adair-Elwyn) tube (see the first image below) or regular endotracheal tube
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Lidocaine jelly or any other water-soluble lubricant
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Magill forceps (see the second image below)
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Afrin spray (oxymetazoline 0.05%)
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Nasal trumpets
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Syringe to inflate the cuff
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Suction
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Intubation equipment - Laryngoscope, GlideScope, fiberoptic scope
Commercial airway device adjuncts are available. The GlideScope Video Laryngoscope (GVL, Verathon Medical Inc., Bothell, WA) intubation system has an established role in routine and difficult orotracheal intubation not only by experienced handlers but also by novices. [6, 7, 8]
Patient Preparation
Anesthesia
If, on the basis of the physical examination or prior history of intubation, no difficulties are expected in securing the airway, general anesthesia and neuromuscular blockade can be induced. General anesthesia is routinely induced using rapid-acting hypnotic or induction agents (eg, propofol, etomidate, thiopental, ketamine).
After anesthesia induction, assess the ability to carry out mask ventilation before giving neuromuscular blockers (except in the case of rapid sequence induction, when mask ventilation is not attempted, and succinylcholine or rocuronium is administered simultaneous to the hypnotic agent). After the neuromuscular blocker drug is administered and given time to achieve maximal effect, perform direct laryngoscopy or blind intubation.
Lubricants and vasoconstrictors are commonly applied to the nasal passages before the introduction of an endotracheal tube. Various vasoconstrictors are available (eg, cocaine 4% solution [not to exceed 1.5 mg/kg], oxymetazoline 0.05% nasal spray, or phenylephrine nose drops 0.25-1%). The choice of vasoconstrictor usually depends on the anesthetist's preference. Applying lidocaine jelly or water-soluble lubricant allows for smoother advance, as well as better transfer of rotation along the endotracheal tube's length during directional manipulation.
If awake fiberoptic intubation is necessary, prepare the nasal passages as described above. Additionally, in awake or sedated patients, topical anesthesia to the larynx and pharynx is also required. This can be accomplished with a number of techniques, such as transoral application of a local anesthetic agent or use of superior laryngeal nerve block with 4% lidocaine (up to 3 mg/kg) administered transtracheally or sprayed down the fiberscope's lumen intermittently in advance of the scope's passage. Incomplete topical anesthesia not only causes patient discomfort but also makes the procedure much more difficult and may lead to morbidity.
An antisialagogue drug (eg, glycopyrrolate 0.2-0.3 mg IV) is administered to improve the visualization of the field. Small amounts of sedation are advocated as well, with the caveat that sedation is not a substitute for a well-anesthetized airway. [9]
Positioning
For the induction of general anesthesia, the patient should be in the supine position.
If awake fiberoptic intubation (or any other awake intubation) is pursued, often the most practical position may be sitting (on the operating room table), in that this will prevent the larynx from falling posteriorly as it does in the supine position.
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Nasal RAE (Ring-Adair-Elwyn) endotracheal tube.
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Magill forceps.
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Inserting nasal trumpet. Note that insertion angle is almost perpendicular to face.
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Nasal trumpet insertion (continued).
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Direct laryngoscopy with Miller blade. Insert nasal RAE endotracheal tube, and advance it a little before putting laryngoscope in mouth.
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Once vocal cords are seen, endotracheal tube is advanced by laryngoscopist or assistant.
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Endotracheal tube is advanced with Magill forceps by laryngoscopist. Assistant helps advance tube by slowly pushing it in.
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Magill forceps directing endotracheal tube (above cuff) for its advance through vocal cords.
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Nasotracheal intubation (blind and unblinded). Video courtesy of Therese Canares, MD, and Jonathan Valente, MD, Rhode Island Hospital, Brown University.
