Indications for Nasotracheal Intubation
Nasotracheal intubation (NTI) is a common form of airway management [1]. During NTI, an endotracheal tube enters the patient’s trachea, following the pathway of the narrow nasal cavity [1]. Physicians need to be well aware of the indications and contradictions of NTI to ensure a favorable outcome for the patient [1]. According to those indications, special precautions or an alternate form of airway management may be necessary [1].
Multiple types of surgeries call for the use of nasotracheal intubation [1]. Often, NTI is used on patients undergoing oral and maxillofacial surgery, given the improved surgical field and mobility that it offers physicians during such operations [1]. More specifically, NTI can be appropriate for intranasal, oropharyngeal, mandible, dental, orthognathic, and rigid laryngoscope and orthognathic surgery [1, 2]. It can also be the airway management procedure of choice for patients receiving tonsillectomies, as well as for those undergoing “complex intra-oral procedures” that require mandibular reconstruction [2, 3].
Beyond certain types of surgery, other situations also benefit from the use of NTI. For one, patients who, due to trismus, have a limited mouth opening, should avoid orotracheal intubation and, therefore, turn to nasotracheal intubation [1]. Additionally, patients who suffer from either cervical spine degeneration or instability may benefit from NTI [1].
Anesthesia providers must also consider a variety of contraindications before deciding on nasotracheal intubation as their strategy of choice. Patients with basilar skull fractures, either with or without corresponding cerebrospinal fluid leakage, could experience severe trauma in their frontal lobes during NTI [1]. Coagulopathy can also place patients at risk of complication via severe epistaxis [1]. Other contraindications for NTI include midface instability, prosthetic heart valves, frequent epistaxis, epiglottitis, and nasal bone fracture [2]. If a patient has foreign bodies in their nasal passage, such as sizeable polyps, or has undergone recent nasal surgery, they may also not be a suitable candidate for NTI [2]. More recently, Zhu et al. found evidence to suggest that having a retropharyngeal internal carotid artery can narrow the pharyngeal cavity and even increase the risk of a tear during intubation [3]. Consequently, it may be beneficial for anesthesia providers to consider RICA before intubation to determine whether the nasotracheal technique is appropriate.
Technical and tube-related contraindications should also be considered. In terms of tube factors, physicians should carefully prevent the selection of too big of a tube, heightened cuff pressure, and the co-existing presence of a nasogastric tube [4]. As for technology, poor larynx visualization, several intubation attempts, and forceful intubation may also compromise the success of nasotracheal intubation [4].
To successfully identify indications and contraindications before deciding on NTI as the correct course of action, physicians should first engage in a meticulous pre-anesthesia evaluation within 48 hours of surgery [4]. During that time, it may become clear which side of the nose should be the one through which the endotracheal tube is passed [4]. However, if the physician remains undecided following the evaluation, a physical exam or an anterior rhinoscopy can be helpful [4]. To reduce the risk of complications, physicians can use a softened or smaller tube, as well as adrenaline to constrict the patient’s blood vessels, depending on the patient’s unique risk factors [5].
In the end, developing a patient-specific strategy that takes into account all relevant indications and contraindications, and applies techniques to meet those needs, is essential to successful nasotracheal intubation.
References
[1] D. H. Park et al., “Nasotracheal intubation for airway management during anesthesia,” Anesthesia and Pain Medicine, vol. 16, no. 3, p. 232-247, July 2021. [Online]. Available: https://doi.org/10.17085/apm.21040.
[2] T. B. Folino, G. McKean, and L. J. Parks et al., “Nasotracheal Intubation,” Treasure Island (FL): StatPearls Publishing, Updated January 19, 2021. [Online]. Available: https://www.ncbi.nlm.nih.gov/books/NBK499967/.
[3] W-P. Zhu et al., “Retropharyngeal internal carotid artery: a potential risk factor during nasotracheal intubation,” Surgical and Radiologic Anatomy, p. 1-8, June 2021. [Online]. Available: https://doi.org/10.1007/s00276-021-02784-9.
[4] D. Prasanna and S. Bhat, “Nasotracheal Intubation: An Overview,” Journal of Maxillofacial Oral Surgery, vol. 13, no. 4, p. 366-372, October-December 2014. [Online]. Available: https://doi.org/10.1007/s12663-013-0516-5.
[5] D. G. Canpolat and S. O. Yasli, “Does a Nasal Airway Facilitate Nasotracheal Intubation or Not? A Prospective, Randomized, and Controlled Study,” Journal of Oral and Maxillofacial Surgery, vol. 79, no. 1, p. 89.e.1-89.e.9, January 2021. [Online]. Available: https://doi.org/10.1016/j.joms.2020.08.029.