Kiesselbach plexus (Little area) is a vascular network located on the anterior aspect of the septum in each nostril. Epistaxis most often originates from this area. Vasoconstrictors may help limit epistaxis and have the added benefit of increasing the caliber of the nasal chamber. Many vasoconstrictors exist including topical cocaine, oxymetazoline, and neosynephrine. During the act of inserting a nasal trumpet or a nasotracheal tube (NTT), it is generally recommended that the device be inserted in the nostril such that the leading edge of the bevel (the pointed tip) is away from the septum. The goal is to minimize the chances of trauma and bleeding from this very vascular area. This means that the device is inserted “upside down” in the left nostril and rotated 180 degrees after the tip has proceeded beyond the cartilaginous septum. Although some authors have recommended the opposite (i.e., that the bevel tip approximate the nasal septum to minimize the risk of damage and bleeding from the turbinates), the bevel away from the septum approach makes more sense and is the recommended method.

The major nasal airway is between the laterally placed inferior turbinate, the septum, and the floor of the nose. The floor of the nose is tilted slightly downward front to back, approximately 10 degrees to 15 degrees. Thus, when a nasal tube, trumpet, or fiberscope is inserted through the nose, it should not be directed upward or even straight back. Instead, it should be directed slightly inferiorly to follow this major channel. Before nasal intubation of an unconscious adult patient, this author recommends gently but fully inserting one’s gloved and lubricated little finger into the nostril to ensure patency and to maximally dilate this channel before the insertion of the nasal tube. In addition, placing the endotracheal tube (ETT; preferably an Endotrol tube) in a warm bottle of saline or water softens the tube and attenuates its damaging properties.

The nasal mucosa is exquisitely sensitive to topically applied vasoconstricting medications such as phenylephrine, epinephrine, or oxymetazoline. Shrinking the nasal mucosa with a vasoconstricting agent can increase the caliber of the nasal airway by as much
as 50% to 75% and may reduce epistaxis incited by nasotracheal intubation, although there is little evidence to support the latter. Cocaine has been implicated in coronary vasoconstriction when applied to the nasal mucosa; so it should be used with caution in patients with coronary artery disease or avoided altogether.^1,2 Evidence suggests that topical vasoconstrictor and local anesthetic agents are not necessary to perform flexible nasoendoscopy.

The nasal cavities are bounded posteriorly by the nasopharynx. The adenoids are located posteriorly in the nasopharynx just above the nasal surface of the soft palate and partially surround a depression in the mucosal membrane where the eustachian tube enters the nasopharynx. During insertion, the NTT often enters this depression, and resistance is encountered. Continued aggressive insertion can cause the NTT to penetrate the mucosa and pass submucosally deep to the naso- and oropharyngeal mucous membranes (Fig. 2.2). Although it is alarming when one recognizes that this has occurred, no specific treatment is indicated, except withdrawing the tube and trying the opposite nostril should nasal intubation be deemed appropriate. Despite the theoretical risk of infection, there is no literature to suggest that this occurs.^3,4,5 Documentation of the complication and communication to the accepting team on admission is important.

The soft palate rests on the base of the tongue during quiet nasal respiration, sealing the oral cavity anteriorly.

The contiguity of the paranasal sinuses with the nasal cavity is believed to be responsible for the infections of the paranasal sinuses that may be associated with prolonged nasotracheal intubation.⁶ Although this fact has led some physicians to condemn nasotracheal intubation, fear of infection should not deter the clinician from performing nasotracheal intubation when required. Securing the airway takes precedence over possible later infective complications, and in any case, the intubation can always be changed to an oral tube or tracheostomy, if necessary.

A nasotracheal intubation is relatively contraindicated in patients with basal skull fractures (i.e., when the maxilla is fractured away from its attachment to the base of the skull) because of the risk of penetration into the cranial vault (usually through the cribriform plate) with the ETT.⁷ Careful technique avoids this complication: the cribriform plate is located cephalad of the nares, and tube insertion should be directed slightly caudad (see previous discussion). Maxillary fractures (e.g., LeFort fractures) may disrupt the continuity of the nasal cavities and are a relative contraindication to blind nasal intubation. Again, cautious insertion, especially if guided by a fiberscope, can mitigate the risk.