Chapter 126

CHAPTER 126 ■ Dental Procedures: Anesthetic Considerations 2085
Figure 126-1. Red rubber catheter placed over the distal end of
the preformed nasotracheal tube.
A
become dislodged during laryngoscopy and potentially be
aspirated. Methods of relatively atraumatic intubation can reduce
these complications of nasal intubation. One of the more common
difficulties encountered is once the ETT has passed the
vocal cords, there is obstruction at the level of the cricoid cartilage.
This is easily overcome by turning the tube at the nose to redirect
the distal end. A variety of other techniques have been
proposed to aide in atraumatic intubation. The following are some
methods that have been suggested: Various tube guides, precurving
the ETT, thermosoftening the ETT, and topical nasal
vasoconstrictors.
The use of a red rubber catheter as a guide for the nasotracheal
tube was shown to reduce the severity of bleeding. 23 The flared
end of the #10–12 French red rubber catheter is placed over the tip
of the tube (Figure 126–1). After lubricating the catheter with
water-soluble lubricant, the distal end of the catheter is placed into
the patient’s nasal cavity. The tip of the catheter is then retrieved
from the oral cavity with a Magill forceps and disconnected from
the nasotracheal tube, which is then advanced into the trachea. 24
For nasal passages through which it is difficult to pass the
nasotracheal tube, a suction catheter can be used as a guide. The
suction catheter is placed inside the tube prior to insertion into
the chosen nares (Figure 126–2). The catheter will help navigate
Figure 126-2. Suction catheter placed inside a 5.0 nasal RAE tube.
B
Figure 126-3. Stylet placed in the distal end of the preformed
nasotracheal tube to form a pigtail.
through the nasal passage first and then the nasotracheal tube can
follow over it similar to the Seldinger technique
Precurving the nasal tube can also aid the intubation process.
A stylet can be inserted into the end of a nasotracheal tube which
can then be bent to resemble a pigtail 5 to 10 minutes before the
beginning of the case (Figures 126–3, 126–4, and 126–5). Just
before using the tube, the stylet is withdrawn from the tube. As a
result the tube will have a slight curve to it. This will help facilitate
the passage of the tube as it is less likely to be caught up in the
bulge of the posterior nasopharynx at the level of C2. Additionally,
with the tip of the tube pointing ventrally, guiding the tube into the
trachea may be accomplished without need for a Magill forceps,
although one should always be available.
One of the most common methods to allow atraumatic
nasotracheal intubation is thermosoftening of the tube. When the
distal 2 to 3 centimeters of the tube is placed in sterile water, heated
to at least 450°C for several seconds immediately before insertion,
ETT passage through the nasal cavity is similar to a soft nasophyarngeal
tube, thus reducing the incidence of epistaxis. 25 It
should be noted that heating of too much length of the ETT can
make it difficult to “turn the tube” to allow passage past the cricoid
cartilage, as the ETT may be so soft that it twists on itself.