Nasal intubation
Introduction
Nasal intubation is often used to increase intraoral exposure during head & neck surgery. Indications include:
- transoral robotic surgery
- maxillofacial surgery
- dental surgery
- restricted mouth opening
- cervical spine instability
- lower facial trauma
- structural abnormalities that preclude oral intubation
Contraindications to nasal intubation include severe bleeding diathesis, anticoagulation, and base of skull fractures. Advancing a nasal tube of any kind in a patient with a base of skull fracture risks penetration into the brain.[1]
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
Vasoconstriction of the nasal mucosa may be achieved using oxymetazoline 0.05%, lidocaine 3-4% with phenylephrine 0.25-1%, or cocaine 4-10%.[1] The hemodynamic effects of cocaine and phenylephrine should be anticipated and planned for accordingly.
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]
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. Therefore, they 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. Alternatively, microlaryngeal tubes may be used as smaller sizes (5.0 mm and 6.0 mm internal diameter) are sufficiently long to be used for nasotracheal intubation.
Complications
The most common complication of nasal intubation is mucosal trauma leading to epistaxis. This most commonly occurs in the setting of inadequate vasoconstriction, larger diameter endotracheal tubes, excessive force, and repeated insertion attempts.[1] Softening the endotracheal tube in hot water may reduce the risk of epistaxis.[3] 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, in an attempt to tamponade bleeding.[1]
Another possible serious complication is necrosis of the nasal ala, which occurs due to pressure from the nasal tube. Alar necrosis may occur quickly: it has been reported in nasal intubations of even short duration.[1] Careful securement of the nasal tube that avoid pressure on the nasal ala is essential for preventing this complication.
Rarely, more serious complications occur such as avulsion of turbinates or nasal polyps, posterior pharyngeal wall laceration, and sinusitis.
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Hall, C. E. J.; Shutt, L. E. (2003-03). "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. Check date values in:
|date=(help) - ↑ Adamson, D. N.; Theisen, F. C.; Barrett, K. C. (1988-05). "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. Check date values in:
|date=(help) - ↑ Lu, P. P.; Liu, H. P.; Shyr, M. H.; Ho, A. C.; Wang, Y. L.; Tan, P. P.; Yang, C. H. (1998-12). "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. Check date values in:
|date=(help)