WHAT PEOPLE WITH AMYOTROPHIC
LATERAL SCLEROSIS
(ALS) SHOULD KNOW ABOUT
NASAL VENTILATION
By Pamela A.
Cazzolli, R.N.
Amyotrophic lateral sclerosis (ALS) is a
degenerative disease of the motor nerves, occurring mostly in adults. Ultimately, this results in progressive
respiratory muscle weakness, causing progressive inability to move air in and
out of the lungs. This eventually leads
to breathing failure, unless respiratory weakness is effectively treated with
mechanical ventilation to maintain breathing.
In fact, when respiratory failure is prevented and treated, and other
treatable complications are avoided, ALS itself is not fatal. Until the 1990s, people with ALS used
tracheostomy positive pressure ventilation (TPPV), usually as a result of
emergency hospitalization, without advance decision making. A tracheostomy is a surgical opening made in
the neck; ventilation is provided through a tube inserted in the windpipe, the
trachea. Tracheostomy ventilation is
“invasive” life support, and through this alternative, people with ALS may
choose to prevent respiratory failure; this may allow life to continue as long
as five to ten or more years in some cases.
In the past decade, however, nasal positive pressure ventilation (NPPV)
has become the treatment of choice for ALS and often an alternative to
tracheostomy. Nasal ventilation can be
used successfully to treat respiratory symptoms, as well as to prevent and
treat respiratory failure in ALS, thus increasing survival in selected
individuals. Use of nasal ventilation
also provides experience and time for people with ALS to decide whether to have
a tracheostomy, if nasal ventilation fails.
Nasal ventilation is a noninvasive treatment in
which a portable ventilator delivers positive pressure air through the nose,
into the lungs; inflating the lungs. The ventilator uses air from the room and
delivers the air to the lungs, through a long plastic tubing attached to a
nasal interface. A nasal interface is
either a small silicone mask fitted around the nose, or “nasal pillows” that
are cushioned inserts that fit comfortably inside the nostrils. The nasal interface is anchored to the nose
by wearing special straps or headgear.
Some people can use a mouthpiece (straight, angled, or one with a lip
seal) in the daytime if their lip muscles can hold on to the mouthpiece without
air escaping from the mouth, or by using straps. Rotating from one interface to another can help promote comfort
and to avoid pressure to the same areas of skin.
People who have trouble keeping their mouth closed
may need to use a chin-strap to close the mouth. Full face masks are also
available to alleviate problems due to air leaks from the mouth or congested
nasal passages. These are not used
frequently because they impair the ability to talk, as well as increase the
risk of aspirating oral secretions.
The best candidates for nasal ventilation are people
who are “nonbulbar” (those who can talk and swallow and do not have excessive
oral secretions). In fact, people are nonbulbar are sometimes able to
successfully use nasal ventilation for up to 24 hours a day, unless bulbar
symptoms become advanced. Studies have shown that some nonbulbar ALS patients
who have used nasal ventilation have prolonged their survival for as long as
six years, until bulbar impairment became severe. Thus, nonbulbar users of NPPV
tend to live longer than those who are bulbar, unless tracheostomy is
used. Factors for successful NPPV use
include: the absence of excessive oral
secretions, effective airway clearance, properly fitting nasal or oral interfaces,
willingness to wear interfaces, the desire to live, and good caregiver support.
Initiating nasal ventilation at the appropriate time
is essential in order to treat early symptoms, prevent respiratory failure,
avoid emergency decision making, and prevent unwanted tracheostomy. Nasal
ventilation should be initiated when significant respiratory decline is
detected. Symptoms of respiratory
impairment vary widely; and may include: shortness of breath, the inability to
take a deep breath, a weak cough force, discomfort in breathing in any position
except sitting or standing upright and a low voice volume. Some people
experience headaches, particularly in the morning, daytime drowsiness or
restlessness. Because signs of respiratory muscle weakness may be overlooked,
careful and accurate monitoring of the
respiratory status is necessary. People
with ALS should have periodic pulmonary function tests (PFTs) and an evaluation
by a pulmonary physician. This will
help assess the degree of respiratory muscle involvement, the progression of
symptoms, early recognition of reversible complications, and pending
respiratory failure. Then a good
decision can be made as to when nasal ventilation should be started. One of the
simple tests that indicates significant respiratory impairment is a vital
capacity (VC) of 50% or less. People with ALS should know the results of their
pulmonary tests and what they mean.
This will allow ALS individuals and their families to participate
collaboratively in decision making with their doctors.
Noninvasive nasal or mouthpiece ventilation can be
provided with either a volume cycled or a bi-level ventilator. The volume ventilator delivers a preset
volume of air for each breath cycle.
The bi-level ventilator delivers two preset levels of pressure: one
level of air pressure is for inhalation, called the “IPAP” (inspiratory
positive airway pressure) and the other for exhalation, called the “EPAP”
(expiratory positive airway pressure). To
achieve and maintain adequate ventilation and relief of respiratory symptoms,
appropriate ventilator settings are essential. The IPAP setting should be set
high enough to
adequately inflate the lungs, while the EPAP should
be low, since the higher the EPAP, the more difficult it may be to exhale. To
maintain ventilation, people with ALS who use a bi-level ventilator should use
one that includes a Spontaneous / Timed (S/T) mode. The Spontaneous
mode assists the breath, each time you start to breathe in. While the Timed mode provides regular assisted breaths that do not require
your own effort, breaths are provided if you are unable to do so.
People with ALS should not use CPAP (continuous
positive airway pressure) machines because this increases the work of breathing
out. CPAP is used to treat obstructive
sleep apnea, rather than for neuromuscular disorders where “assisted
ventilation” is needed.4 Also, oxygen should not usually be used as
a substitute for positive pressure ventilation. Use of oxygen alone can result
in respiratory failure when assisted ventilation is needed to treat respiratory
muscle weakness. Sometimes oxygen will be needed in addition to assisted
ventilation if a person has pneumonia or a lung disease.
Nasal ventilation is usually initially used when
sleeping at night and during naps during the day. The amount of hours necessary to relieve symptoms and to maintain
optimal ventilation depends on each person’s changing respiratory status. Thus, NPPV is not needed “only” when
sleeping. The progression of
respiratory muscle weakness will gradually increase the need to use NPPV if
maintaining ventilation is desired.
Although the physician must prescribe the type of
ventilator and the settings, the respiratory therapist should work in conjunction
with the physician and patient to help evaluate and identify optimal settings.
The ventilator settings should be adjusted for the patient’s comfort and relief
of symptoms. Only the patient can
determine what is most comfortable. Patients who are not comfortable will not
use their ventilator. Initiation of
nasal ventilation requires sufficient time to adapt to the new equipment and to
make adjustments for the desired
outcome. Therefore, it is often ideal
for the respiratory care practitioner to initiate the treatment in the
patient’s home. Careful follow-up
visits are needed to be sure that the ventilator settings are adjusted as
needed. A simple pulse oximeter reading
should be done at each visit to be sure that oxygen saturation is 95% or greater,
without supplemental oxygen.
Initially, noninvasive NPPV was
developed using volume ventilators. The
bi-level ventilator was first introduced in 1990 by Respironics, Inc.
(Pittsburgh, PA) and their original model with the spontaneous / timed mode
was called, the Respironics BiPAPâ S/T, meaning “Bi” for the two levels of pressure, and
“PAP” for positive airway pressure. As the pioneer of bi-level ventilation, the Respironics “BiPAP” became
widely used; no other bi-level machine became available until later. Thus, when bi-level ventilation became more
prevalent, all the bi-level ventilators have been commonly referred to as the
“BiPAP.” However, “bi-level ventilator”
is the best general term. Although
other brands are available, the BiPAP should only be used to refer to the
Respironics bi-level ventilator. Other
leading bi-level models include: the
KnightStar 335 (Mallinkrodt Inc., Pleasanton, CA), the Sullivanâ VPAPâ II ST-A (ResMed Corp,
Poway, CA) and the Quantum PSV (Respironics, Inc.).
The bi-level and volume ventilators have advantages
and disadvantages. The bi-level
ventilators are simple to use, lighter weight (ranging 7.7 to 19 pounds), and
less expensive. They compensate for air
leaks. Although they have no built-in
battery, most are able to be adapted to run on an external battery that is kept
charged. The volume cycled ventilators
may be more complex to use, more expensive and weigh an average range of 28 to
35 pounds. However, they are more
powerful, have more safety features, and have an internal battery that
automatically works if there is a power failure. They are able to run a few hours without an external battery, but
are designed to attach easily to an external battery. One of the latest ventilator models is the Pulmonetic
Systems: LTV1000 (Colton, CA), a
ventilator that is both a pressure support and volume cycled unit. It is the size of a laptop computer, weighs
only 12.6 pounds, but is more expensive.
Whatever ventilator is used, people with ALS should
have the right to indicate their ventilator preference, know their prescribed ventilator settings
and what they mean. To assure on-going
and safe use, ventilator users should only use a ventilator that has an
external battery, as well as a cigarette lighter adapter to run on a vehicle
battery. Patients and families should
understand and be skilled in the use of their respiratory equipment. This includes knowing the ventilator settings
and sometimes how to change settings if needed (such as the IPAP pressure if necessary
within the parameters prescribed by the physician). Therefore, use of a ventilator with easy access to the controls
(note: some bi-level devices are designed so the user has no access to the
controls). The patient or family should
report immediately if the delivery of air no longer feels sufficient or
comfortable so their doctor, nurse and respiratory practitioner can quickly
respond. You need a clear contingency
plan, so you know what to do in case problems occur.
People with ALS, and their loved ones, have the
right to accurate, sufficient and understandable information for planning and
decision making. This will allow the
best choices, and avoid making hasty decisions. It is wiser to plan well ahead than to be one minute too
late. The objective is to achieve your
goals, to achieve optimal life satisfaction.
REFERENCES:
Special
thanks to Edward A. Oppenheimer, MD of Kaiser Permanente Medical Center, Los
Angeles for the review of this article.
Revised: August 2000
Ó 2000.
Pamela A. Cazzolli, R.N., Canton, Ohio USA. All Rights Reserved.
Reprinted with permission by Pamela A. Cazzolli,
R.N., ALS Nurse Consultant in Canton, OH.
During her practice, she has interacted with over 2000 people with
ALS. For many years, she served as the
Nurse Consultant of the ALS Association Eastern Ohio Chapter, including six
years as the Nurse Coordinator of the ALS Center at the Cleveland Clinic
Foundation. As a pioneer investigator
of the use of nasal ventilation in ALS patients, she was one of the first to
report that nasal ventilation prolongs survival in selected individuals with
ALS.