9
THE NASOPHARYNGEAL TUBE AND OBSTRUCTIVE SLEEP APNEA
TREATMENT
By Regina Patrick, RST, RPSGT
C
ontinuous positive airway pressure (CPAP) treatment has
the greatest success in treating obstructive sleep apnea
(OSA). Surgical treatment for OSA is less successful. For
example, uvulopalatopharyngoplasty (UPPP) successfully treats
OSA in approximately 50 percent of patients.1 A possible
explanation for the decreased success rate with the UPPP
surgery is that it primarily focuses on the oropharynx. However,
episodes of apnea can persist if an obstruction occurs in the
glossopharyngeal airspace (i.e., the portion of the airway by
the base of the tongue), even if the oropharynx is sufficiently
open. Conventional examinations (e.g., endoscopy) of the
upper airway can give some clues about where an obstruction
may be occurring. However, conventional examinations are
performed in a patient who is awake, and what happens in
the airway during sleep can not be assessed. The inability
to assess the airway during sleep makes it difficult to
diagnose glossopharyngeal obstruction. A simple tool, the
nasopharyngeal tube, which is typically used to create an
emergency airway, may be able to counteract this difficulty
by allowing sleep workers to indirectly determine whether an
obstruction is taking place in the glossopharyngeal airway.
Knowing this distinction may improve surgical treatment for
patients with OSA.
In a person with OSA, the upper airway muscles relax excessively
during sleep. As a consequence, tissues such as the tonsils and
adenoids that are supported by the muscles are drawn into the
airway and block airflow. The oxygen saturation in the blood
falls, which ultimately triggers a brief arousal. On arousing,
the upper airway muscle tone is restored and the airway opens.
This allows a person to take a few deep quick breaths to restore
the oxygen level. Once the oxygen level is restored, the person
resumes sleep. However, once asleep, another apnea can occur.
The most common approach to treat OSA is to prevent the
collapse of the upper airway. CPAP accomplishes this by blowing
pressurized air into the airway through the nose or nose and
mouth. The pressure of the air pushes against the wall of the
airway, thereby preventing the collapse of the airway during
sleep.
Regina Patrick, RST, RPSGT, has been
in sleep field for more than 20 years
and works as a sleep technologist at
the Wolverine Sleep Disorders Center in
Tecumseh, Mich.
Tonsillectomy and adenoidectomy. The tonsils and
adenoids are removed by radiofrequency waves (i.e.,
radiofrequency ablation), electrocautery, surgical scalpels
or snares or laser device.
UPPP. The uvula, tonsils and adenoids and excess fatty
tissue in the oropharyngeal airway are removed by electrocautery or laser device.
Laser-assisted uvulopharyngoplasty. By using a laser
device, the soft palate is reshaped and the tip of the
uvula is removed to form a smaller uvula. Unlike UPPP,
the tonsils and adenoids are not removed.
Uvulopalatal flap. In the uvulopalatal flap procedure,
the tip of the uvula is removed. The remaining portion
of the uvula is folded forward (i.e., toward the teeth)
and sutured in place on the soft palate.
Radiofrequency ablation of the tongue base. Radiofrequency energy is used to remove a portion of the base of
the tongue. This procedure is used to treat mild OSA.
In 1977, Kravath and colleagues2 inserted nasopharyngeal tubes
in infants who had OSA and chronically enlarged tonsils and
adenoids. Kravath found that the number of OSA episodes
decreased once the nasopharyngeal tube was inserted. The tonsils
and adenoids were later removed. Based on this experience,
Kravath encouraged researchers to investigate using the
nasopharyngeal tube to treat OSA.
Other researchers soon began to investigate using the
nasopharyngeal tube to treat OSA. In 1985, Monroe Karetzky
and colleagues3 reported successfully treating OSA with a
nasopharyngeal tube in six of seven patients. In 1988, Jeffrey
Nahmias4 (who had been on the Karetzky team) and colleagues
used the nasopharyngeal tube in a larger number of patients, and
demonstrated a reduction in the number of apneas in most (66.7
percent) patients. In 2010, Huo and colleagues5 reported that
the nasopharyngeal tube was feasible for treating OSA. In two
different studies (one in 2013 and another in 2014), Shuhua Li6,7
demonstrated that the nasopharyngeal tube could be used as a
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REGINA PATRICK, RST, RPSGT
Another approach is to widen the upper airway by surgically
removing tissues that are drawn into the airway during an OSA
episode. With these tissues removed, there is less crowding in the
upper airway and airflow is not obstructed during sleep, even as
the upper airway muscles relax. Surgeries that enlarge the airway
in people with OSA are tonsillectomy and adenoidectomy,
UPPP, laser-assisted uvulopalatoplasty, uvulopalatal flap, and
radiofrequency ablation of the tongue base. Each procedure is
briefly described below.
 Continued from Page 9
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screening tool to determine whether an obstruction is occurring
in the glossopharyngeal airway during an OSA episode.
In the Nahmias study,4 24 patients with OSA underwent
a baseline polysomnographic (PSG) study without a
nasopharyngeal tube. When they were later restudied by PSG
with the nasopharyngeal tube inserted, Nahmias found that
the number of apneas per hour and the number of disordered
breathing events per hour decreased by 62.3 percent and by 39.2
percent, respectively. Patients for whom the nasopharyngeal tube
was not successful had a higher baseline apnea-hypopnea index
(AHI; approximately 76.1 respiratory events per hour), compared
to that of patients who were treatment successes (AHI was 44.1
percent).
In the Huo study,5 29 patients with OSA were assessed by
PSG studies performed before and after the insertion of the
nasopharyngeal tube. When the tube was in place, the AHI
decreased on average by 67.3 percent (from 44.7 events per hour
to 14.6 events per hour), the average time of the longest apnea
decreased by 32.05 percent (from 44.3 seconds to 30.1 seconds),
and the average lowest arterial oxygen saturation increased
by19.2 percent (from 72.2 percent to 86.10 percent). The 29
patients subjectively reported that symptoms improved on the
treatment night and that the improvement was maintained on
the following day. The therapeutic success rate was 65.5 percent,
and was defined as a reduction in the AHI of at least 50 percent
and an AHI of less than 20 events per hour. Among the patients
for whom the treatment was not successful may have been
because obstructions occurred at the tongue base (i.e., in the
glossopharynx airway). Based on these results, Huo suggested
developing the nasopharyngeal tube as a new treatment approach
and using it to evaluate the level of obstruction.
In the 2013 Li study,6 the patients underwent a PSG study
with and without the nasopharyngeal tube inserted. Patients
whose AHI remained 15 events or more per hour with the
tube inserted were evaluated for glossopharyngeal surgery.
Forty-one percent of the patients were treated by UPPP and
glossopharyngeal surgery and 59 percent of the patients were
treated by UPPP alone. The overall treatment success rate was
82.3 percent. In the 2014 study, Li7 used the same procedure
as in the 2013 study. The patients were treated by UPPP and
glossopharyngeal surgery (i.e., the AHI was 15 events or more
per hour) or UPPP alone (i.e., the AHI was less than 15 events
per hour). The success rates of the surgeries were 39.1 percent
and 86.0 percent, respectively. From these two studies, they
concluded that combining glossopharyngeal surgery and UPPP
can significantly improve surgical outcomes in people with OSA;
a nasopharyngeal tube can be used as a diagnostic tool to localize
airway obstruction in patients with OSA; and surgical treatment
based on the results of a PSG with the nasopharyngeal tube in
place has good treatment efficacy.
The nasopharyngeal tube is inserted in only one nostril. The
tube is hollow and straight on one end and flared on the other
end. Before insertion, the straight end of the tube is wiped with
a lubricant to ease insertion. The tube is inserted into the nostril
and pushed gently until the end is at the oropharynx level (i.e.,
at the level of the soft palate). The other end of the tube is flared
to prevent this end from entering the nasal passage. The tube
is inserted until the flared portion reaches the nostril. Once
properly inserted, the tube can be taped to help hold it in place.
The nasopharyngeal tube provides a pathway for air to flow from
the nostril to the oropharyngeal space. If an obstruction is below
the oropharyngeal level (i.e., in the glossopharyngeal airway then
nasopharyngeal intubation will be ineffective in reducing OSA
episodes).5-7
How the nasopharyngeal tube reduces apneic events is unclear.
One conjecture is that the nasopharyngeal tube acts as the sole
conduit for airflow when the upper airway collapses around the
tube.4 Supporting this conjecture is the finding that plugging
the nasopharyngeal tube returns the number of OSA events to
pretreatment levels. 4
The nasopharyngeal tube appears to be a promising tool that
can be used to determine whether obstruction is occurring in the
glossopharyngeal airway or that can be an alternative to CPAP
treatment for some people with OSA who are unwilling to use
CPAP therapy or unable to use CPAP therapy. As a screening
tool, the nasopharyngeal tube may help physicians plan OSA
surgery by identifying patients who have obstruction in the
glossopharyngeal airway and may need to have glossopharyngeal
surgery in addition to or instead of oropharyngeal surgery (e.g.,
tonsillectomy, adenoidectomy, UPPP). This distinction could
thereby improve surgical outcomes.7 Other possible uses for the
nasopharyngeal tube are as a temporary tool to reduce respiratory
events while a patient is losing weight or while a patient is
awaiting to undergo OSA surgery (e.g., tonsillectomy); it could
also be used temporarily when traveling if a person does not
want to carry a CPAP machine on a trip.4
More studies are needed to learn exactly how a nasopharyngeal
tube improves respiratory events in people with OSA and to
determine who most benefits from the therapy. Current research
findings suggest that morbidly obese patients with severe OSA
should ideally be treated by CPAP, whereas patients with mild
to moderate OSA who are not severely obese may benefit from
nasopharyngeal tube treatment.4
REFERENCES
1.
Conway W, Fujita S, Zorick F, et al.
Uvulopalatopharyngoplasty. One-year followup. Chest.
1985;88:385-387.
2.
Kravath RE, Pollak CP, Borowiecki B. Hypoventilation
during sleep in children who have lymphoid airway
obstruction treated by nasopharyngeal tube and T and
A. Pediatrics. 1977;59:865-871.
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3.
Karetzky M, Scoles V, Fourre J, et al. Use of a
nasopharyngeal tube in the treatment ofobstructive
sleep apnea. Sleep Research. 1985;14:176.
4.
Nahmias JS, Karetzky MS. Treatment of the obstructive
sleep apnea syndrome using a nasopharyngeal tube.
Chest. 1988;94:1142-1147.
5.
Huo H, Li WY, Shen P, et al. One night treatment of
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Li SH, Wu DH, Bao JM, et al. Outcomes of upper
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7.
Li S, Wu D, Bao J, et al. The nasopharyngeal tube:
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uvulopalatopharyngoplasty. Journal of Clinical Sleep
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