Total laryngectomy has a wide range of
adverse effects, mainly as a result of the
permanent disconnection of the upper and lower
airways. Not only is the natural voice lost, but
other physiological systems, which require a
more or less normal nasal airflow, are disrupted
and/or hampered as well. This
change in anatomy often leads to
deterioration in pulmonary function, with an
associated range of physical and psychosocial
problems, and a loss (or at least a serious
decrease) of the sense of smell and taste.
Olfaction is either a passive process that
occurs during normal nasal breathing (so-called
passive smelling) or an active process
(so-called active-smelling or sniffing). Total
laryngectomy inevitably results in the loss of
passive smelling, and only a minority of
patients are still able to actively smell
anything.
In a recent study of 63 laryngectomees, we
found that about two thirds of the patients were
anosmic and that the rest had difficulty in
smelling. Several techniques have been described
that might generate an airflow in the nose and
thereby restore olfactory function. However,
these techniques have not been incorporated into
routine rehabilitation methods, and their
effectiveness has not yet been evaluated
either.
Recently, we developed a technique that
makes use of a simple physical mechanism by
creating an "underpressure" in the oral cavity,
which then generates a flow of air through the
nose. Patients are instructed to make an
extended yawning movement while keeping
their lips securely closed and simultaneously
lowering theirjaw, floor of the mouth, tongue,
base of the tongue, and soft palate. The
underpressure thus created in the oral cavity
results in an airflow through the nose. This
technique, which is easily mastered by the
patient, is taught by explaining that this
movement resembles what one does when yawning
with the mouth closed, ie, so-called
polite yawning. This polite yawning
maneuver bas to be repeated rapidly to increase
its effectiveness. In an intervention study, we
were able to show that after only one 30-minute
training session, 25 (57%) of the 44
laryngectomees were able to smell using this
technique.
Although this polite yawning technique is
potentially an important adjunct to the
rehabilitation process, no data are available on
the long-term use of this technique; eg, do
patients continue to apply this method aftersome
months or years and do they apply it in daily
life? Therefore, a followup study was conducted
to study long-term results. Also, because our
original studies used complicated techniques to
assess olfacton, function,in the prescrit study
we also assessed whether a new simple odor
detection test (ODT) could replace our previous
method of odor testing.
[...] Comment : The
correlation between the ODT-POPS combination and
the SDT seems sufficient to justify our decision
to replace this laborious combination (used in
our previous study) with the much simpler SDT.
The results with the combination are slightly
better (54% vs 46%), however, which could mean
that the threshold for being classified as a
smeller might be somewhat lower with the
combination ODT-POPS than with the SDT. This
outcome might be attributable to the strict
criterion of separating normosmia on the one
hand from hyposmia/anosmia on the other. The SDT
has a proven validity and reliability and for
routine clinical practice the use of a single
objective measure has clear advantages. Similar
results were recently reported using the Sniffin
Sticks odor test in a series of
laryngectomees.This latter test, however,
consists of more odors and uses different
concentrations and is therefore much more time
consuming. The simple SDT requires only a few
minutes to be completed.
The main aim of the study was to establish
whether a single training session in the past
had a permanent effect on the use of the NAIM in
daily life. The majority of the patients who
participated in the original intervention study
also took part in the present study (31
[63%] of 49 patients). Because only 4
patients refused to participate (one of them
being a smeller), selection bias concerning the
long-term results is probably minor.
It is remarkable that the percentage of
smellers in this follow-up study is very similar
to that found in the earlier intervention study
(54% vs 57%, respectively). The effectiveness of
the NAIM could be confirmed: there is a
relationship between the correct execution of
the NAIM, as judged on the video recording, and
whether the laryngectomee was a smeller or a
nonsmeller. However, the small number of
patients (16) who are still performing the NAIM
correctly indicates that a single training
session may be insufficient to achieve effective
long-term results. On the other hand, 2 patients
made use of the NAIM an automatism whenever
something in the environment urged them to do
so.
In this way, they compensated for the loss
of passive smelling, which is a "bonus" of
normal nasal breathing and an important aspect
of natural olfaction. As with other
speech-language pathology problems, behavioral
changes are difficult to achieve and repetition
of the training is often a key to success. More
intense training, focusing on the important
movements (lowering of the floor of the mouth
and the jaw while simultaneously avoiding
breathing in) and the fast repetition of the
NAIM is needed to restore olfaction in a higher
percentage of patients and to make the NAIM into
an automatism that may allow passive smelling to
occur again. Two other aims are to perform the
maneuver as discreetly as possible by trying to
lower only the floor of the mouth and to reduce
the movement of the jaw. This attempt to make
the NAIM more inconspicuous is relevant, because
one of the reasons reported by patients for no
longer using the maneuver was that it was too
noticeable.
Whether the patency of the nose and the
volume of air that can be moved with the polite
yawning maneuver have an influence on olfaction
acuity is a question that cannot be answered by
the findings of the present study. Although none
of our patients had overt nasal obstruction,
which was more or less ruled out by nasal
endoscopy, it remains unclear whether
improvement of nasal patency would have a
beneficial effect on the olfactory end result,
as recently has been suggested. ` Along with
studies on the volume of air that can be moved
with the NAIM, rhinometry could maybe provide
more insight in this respect.
Some of the older literature suggests that
there is a positive correlation between the
quality of the esophageal voice and the
olfaction acuity of the patient.We were not able
to evaluate this aspect because all but 2 of the
patients were using a voice prosthesis.
Nevertheless, the afore mentioned relationship
might be merely a result of the better control
of the oropharyngeal musculature in good
esophageal speakers, enabling them to pump air
into the nasal cavity retronasally, as bas been
advocated in the past.' However, we think that
this retronasal route is not very important and
that in the majority of cases the oropharyngeal
movements result in an anteronasal flow of
air.
It should also be noted that the SDT
criterion of a normal sense of smell was
strictly followed, ie, 7 or 8 of the odors
scored correctly. Some of the patients scored
fewer than 7 odors correctly and could be
considered to be to some extent hyposmic and
probably not totally anosmic, which might lead
to an underestimation of the results of the
olfaction rehabilitation. However, by applying
the cutoff scores of the SDT, the norms of
"normal" smelling can be used to compare the
results of laryngectornecs.
Recently, Miwa et al reconfirmed the effects
of olfactory impairment on the quality-of-life
and level of disability. Patients reporting
persistent olfactory impairment after previously
documented olfactory loss indicate a higher
level of disability and a lower quality of life
than those with perceived resolution of
olfactory compromise. These observations are in
agreement with our carlier finding that
laryngectomees who were able to smell reported
having a better taste and appetite. They
emphasize the benefits that can be gained from
olfaction rehabilitation in
laryngectomees.
Conclusions : Odor testing in
individuals who have undergone a total
laryngectoiny is now possible in a relatively
simple way using the easily applied SDT. The
NAIM (best explained to the laryngectomee as a
polite yawning technique) is a patient-friendly
method that can restore the sense of smell.
However, a single training session is probably
insufficient, and most patients may need more
training. This intensified training may then
serve to rehabilitate olfaction in a higher
percentage of patients and to make this maneuver
an automatism to compensate for the loss of
passive smelling after total laryngectomy. In
view of this reconfirmation that it is possible
to restore olfaction in individuals after total
laryngectomy, reliabilitation of the sense of
smell should forni an integral part of the
multidisciplinary postlaryngectomy
rehabilitation program.
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