Nasal intubation is an approach to endotracheal intubation often used to increase intraoral exposure during head & neck surgery.

Indications

  • Transoral robotic surgery
  • Maxillofacial surgery
  • Dental surgery
  • Restricted mouth opening
  • Cervical spine instability
  • Lower facial trauma
  • Structural abnormalities that preclude oral intubation

Contraindications

  • Severe bleeding diathesis
  • Anticoagulation
  • Basilar skull fractures
    • Advancing a nasal tube in a patient with a basilar skull fracture risks penetration into the brain.[1]

Patient evaluation

A history of nasal septal deviation, polyps, and prior nasal surgery should be elicited. Patients with previous reconstructive orofacial surgery or nasal stenosis may have nasal anatomy that does not permit passage of an nasal endotracheal tube. In these cases, preoperative endoscopic airway examination (PEAE) and craniofacial CT imaging is helpful to determine feasibility of nasal intubation.[1]

Preparation of Nasal Mucosa

Topical anesthesia and vasoconstriction

Vasoconstriction of the nasal mucosa may be achieved using oxymetazoline 0.05%. If topical anesthesia is also desirable, lidocaine 3-4% (with phenylephrine 0.25-1%) or cocaine 4-10% may also be used.[1] Prepare for any potential hemodynamic effects from systemic absorption of the drugs and/or additives used.

Mechanical dilation

Serial mechanical dilation of the nares with nasal trumpets prior to nasal intubation is controversial and in some studies has been associated with higher rates of trauma and hemorrhage to friable nasal mucosa.[2] [3]

Selection of Endotracheal Tube

Tubes placed via the nasotracheal route must be of smaller diameter and increased length compared to tubes used for orotracheal intubation.

  • Nasal RAE tubes have a preformed bend at a set depth depending on the internal diameter of the tube
    • Must be sized appropriately by comparing them to the patient's profile in order to ensure that the cuff will lie at the appropriate depth
    • Most patients require a size 7.0 mm internal diameter nasal RAE or larger
  • Microlaryngeal tubes may be used if a smaller diameter is desirable
    • Typically 5.0 mm and 6.0 mm internal diameter are sufficiently long to be used for nasotracheal intubation

Complications

Epistaxis

  • Most common complication of nasal intubation epistaxis from nasal trauma
  • Causes include[1]
    • Inadequate vasoconstriction
    • Larger diameter endotracheal tubes
    • Excessive force
    • Repeated insertion attempts.
  • Softening the endotracheal tube in hot water may reduce risk[4]
  • If bleeding occurs, intubation should be completed quickly if possible.
    • If rapid intubation is not possible, the endotracheal tube should be withdrawn into the post-nasal space and the balloon inflated to tamponade bleeding[1]

Alar necrosis

  • Occurs due to pressure from the nasal tube
  • May occur quickly
    • Has been reported in nasal intubations of even short duration.[1]
  • Prevented by securing the tube such that pressure is avoided on the nasal ala

Other complications

Rarely, more serious complications occur such as avulsion of turbinates or nasal polyps, posterior pharyngeal wall laceration, and sinusitis.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Hall, C. E. J.; Shutt, L. E. (2003). "Nasotracheal intubation for head and neck surgery". Anaesthesia. 58 (3): 249–256. doi:10.1046/j.1365-2044.2003.03034.x. ISSN 0003-2409. PMID 12603455.
  2. Adamson, D. N.; Theisen, F. C.; Barrett, K. C. (1988). "Effect of mechanical dilation on nasotracheal intubation". Journal of Oral and Maxillofacial Surgery: Official Journal of the American Association of Oral and Maxillofacial Surgeons. 46 (5): 372–375. doi:10.1016/0278-2391(88)90220-0. ISSN 0278-2391. PMID 3163370.
  3. Folino, Thomas B.; Mckean, George; Parks, Lance J. (2022), "Nasotracheal Intubation", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 29763142, retrieved 2022-08-17
  4. Lu, P. P.; Liu, H. P.; Shyr, M. H.; Ho, A. C.; Wang, Y. L.; Tan, P. P.; Yang, C. H. (1998). "Softened endothracheal tube reduces the incidence and severity of epistaxis following nasotracheal intubation". Acta Anaesthesiologica Sinica. 36 (4): 193–197. ISSN 0254-1319. PMID 10399514.