Transcript Slide 1

Pulmonary management
of the neuromuscular patient
Tim Short, MBA, BS, RRT
This program has been approved for 1 hour of continuing education credit.
Objectives
• Discuss management of patients with Amyotrophic Lateral Sclerosis
(ALS)
– Secretion removal
– Noninvasive ventilation
– American Academy of Neurology (AAN) practice parameters
• Review the mechanics of airway clearance
• Identify conditions that benefit from secretion mobilization and/or
secretion removal
– Intrinsic disease
– Neuromuscular disease
• Discuss techniques that may be used for airway clearance
Neuromuscular disease
ALS is often referred to as
"Lou Gehrig's Disease"
• Mucociliary transport is often normal
• Amyotrophic Lateral Sclerosis (ALS)
is a progressive neuromuscular
disease that affects nerve cells in
the brain and the spinal cord
• Patients with neuromuscular
disease have an impaired ability to
eliminate secretions
• It may be due to
• Lack of respiratory muscle
strength
• Impaired ability to cough
ALS statistics
• 50 percent die within three years of disease
onset
• 80 percent die within five years of diagnosis
• 10 percent live more than 10 years
NIV has prolonged the length of survival by treating the
respiratory insufficiency.
• ALS occurs in all races
• 1.5 to 1.0 ratio of men to women
ALS
Lung disease
When ALS affects the neurons that control the respiratory muscles,
breathing becomes strained or weak
Begins with shortness of breath during exercise or at night
15 percent never have a breathing problem
In the past, diminished breathing was the usual cause of death.
Now, there are options.
Living with ALS: Adapting to Breathing Changes, 1997, ALS Assoc.
Patient care strategy
Offer a comprehensive approach to the management of the
ALS patient in the home.
• Utilize a bi-level S/T ventilatory support system
• Utilize compliance reporting systems and the device report
• Provide additional therapies as needed
• This allows for identification of patients early in the disease
process, and for the provision of appropriate therapies for
patient management throughout the course of the disease
Lung disease
• Mucociliary transport is often compromised
• Increased sputum production is a result of intrinsic
lung disease
• Patient has intact muscle strength for strong
coughing
Groups at risk for retaining secretions
• Intrinsic lung disease
– Cystic Fibrosis (CF), COPD, bronchiectasis
• Neuromuscular disease
– ALS, muscular dystrophy, post polio, multiple
sclerosis, spinal muscular atrophy
– Spinal cord injury, stroke
Airway clearance cycle
Inhaled
irritant
Lung
damage
• Mucus production
Inflammatory
response
• Biochemical changes
Obstruction
Retained
secretions
Ineffective
airway
clearance
Impact of ineffective cough
Approximately 90% of episodes of respiratory
failure within patients with neuromuscular
disease occur during otherwise benign upper
respiratory infections because of the inability to
clear the airways.
Tzeng AC. Bach JR. Prevention of pulmonary Morbidity for Patients with Neuromuscular Disease. Chest. November 2000:Vol. 118, No. 5; 1390-6
AAN practice parameters
The Care of the Patient with Amyotrophic Lateral Sclerosis
(an evidence-based review)
American Academy of Neurology (1999)
Respiratory Work Group
• Deborah Gelinas, MD
• Edward A Oppenheimer, MD
AAN practice parameters
Five areas of investigation
• Breaking the news
• Symptomatic treatment
• Nutrition
• Respiratory insufficiency and mechanical ventilation
• Advance directives and palliative care
AAN practice parameters
Principles of ALS management
• High priority should be placed on patient autonomy
• Information is appropriately timed for decision-making
• Address the full continuum of care
• Advance directive discussions should be introduced
and re-evaluated by the physician
AAN practice parameters
Pulmonary measurements
• Erect sitting vital capacity
• Supine vital capacity
A decrease in VC to 50 percent is associated with
respiratory symptoms
• Nocturnal oximetry
• Polysomnogram
Measuring cough strength
• Maximum expiratory pressure
– Isolates cough muscle strength
– MEP of 60 cm H2O and higher has been shown to
correlate well with the ability to generate adequate cough
flows
• Peak cough flow
– Simple testing format
– Peak flow meter and mask
– Measure Peak Cough Flow (PCF)
– Normal: 6-12 l/s or 360–720 l/min
Ineffective cough
• Respiratory muscle strength can deteriorate
during respiratory infections
• PCF between 160 l/minute but less than 270
l/min are also at risk
• For this reason, a PCF of 270 l/min has been used
to identify patients who would benefit from
assisted cough techniques
Bach J, Ishikawa Y, et al. Prevention of pulmonary morbidity for patients with Duchenne muscular dystrophy. Chest
1997;112 (4):1024-28
Ineffective cough
• PCF < 160 l/min
– Increases risk of respiratory infection
– Introduces risk of chronic lung damage as a
result of recurring lung infection
– Increases risk of pneumonia and resulting
hospitalizations
Airway clearance therapies
What to use?
Understanding airway clearance methods
• Secretion removal
Techniques that mobilize and remove secretions from
the lungs
• Secretion mobilization
Techniques designed to loosen and mobilize secretions
from the lower airway to the upper airway
Secretion clearing/removal techniques
– Suctioning
– Manually assisted cough (MAC)
– Mechanical insufflation-exsufflation (MI-E)
Secretion mobilization techniques
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Manual chest physiotherapy and postural drainage
External percussion and vibration devices
High frequency chest wall oscillation (HFCWO)
Aerosol therapy
Positive expiratory pressure devices (PEP)
Intrapulmonary percussive ventilation (IPV)
Effective cough needed to clear mobilized secretions
Secretion mobilization techniques
“...are effective in mobilizing retained mucous
secretions for patients with sick lungs (intrinsic),
such as CF and COPD, although these devices will
not help a patient whose main problem is impaired
cough clearance.”
Finder, JD. Review of Airway Clearance Technologies 2006. RT Magazine July 2006 22-25.
Mechanical insufflation-exsufflation (MI-E)
• Assists patients to clear retained secretions
noninvasively
• Applies a positive pressure to the airway
(insufflation) followed by a rapid shift to a negative
pressure (exsufflation) simulating a cough
• May be applied by mask or mouthpiece or
invasively via endotracheal or tracheostomy tube
Indications for use for Cough Assist
Any patient unable to cough or clear secretions
effectively due to reduced peak cough expiratory
flow < 270 l/min
Contraindications
• History of bullous emphysema
• Known susceptibility to pneumothorax or pneumomediastinum
• Recent barotrauma
Benefits of insufflation
 Neuromuscular disease - reduced VC and Vt
and an inability to sigh that result in
developing atelectasis and pneumonia1
 Provides normal hyperinflation - has been
shown to combat loss of chest wall
compliance and microatelectasis2
1 Estenne M. et al. Lung volume restriction in patients with chronic respiratory muscle weakness:
the role of microatelectasis. Thorax 1993:48(7):698-701
2 Estenne M. et al. Chest wall stiffness in patients with chronic respiratory muscle weakness.
Am Rev Respir Dis 1983;128(6):1002-1007
Benefits of exsufflation
• Flow simulates a natural expiratory cough flow (610 l/sec)
• More effective than invasive suctioning since
suctioning has been shown to miss the left
mainstem bronchus 90% of the time1
• Potentially eliminates the need for invasive
suctioning
1 Bach Jr. Room For Imagination:Inspiratory and expiratory muscle aids. Advance. April 2006: 58-60
MI-E treatment
Inhale + Exhale + Pause
=
Repeat cycle 4-6 times
Rest 20-30 seconds
Repeat sequence 4-6 times
Cycle
Typical MI-E settings
• Pressures (positive and negative)
– Start low, 10 to 15 cm H2O
– Get patient acclimated to device
– Increase pressures as tolerated, 35 to 45 cm H2O ideally1
• Times (inhale, exhale and pause)
– Small children: 1 to 2 sec
– Adults: 2 to 3 sec
1 Gomez-Marino E et al.Mechanical insufflation-exsufflation. Pressure,volume, and flow relationships and the adequacy
of the manufacturer’s guidelines. Am J Phys Rehabil 2002;81(8):579-583.
Settings
• The goal of inspiratory pressure is to give the
patient a good hyper-expansion
• The goal of expiratory pressure is to replace a
good expiratory cough flow
• Pressures and times vary with each patient
Settings
• Important to work with patient to find settings which
are both comfortable and effective
• Studies have shown that therapeutic PCF may not
be reached with MI-E expiratory pressures less
than -40 cm H2O
Clinical benefits
Mean peak cough expiratory flow rates of 21
patients with NMD studied
– Unassisted
1.81 ± 1.03 L/sec
– Assisted cough 4.27 ± 1.29 L/sec
– MI-E & MAC
7.47 ± 1.02 L/sec
(Normal PCF is 6-12 L/sec)
Conclusion: In-exsufflator cough machine
improved peak cough expiratory flow rates
Bach J. Chest 1993; 104:1553.
Therapy combination benefits
10
MI-E & MAC produced the
most effective cough flows
8
6
4
2
0
Unassisted
MI
MI + MAC MI-E+MAC
Bach et al: Chest, 1993; 104:1553-62.
Noninvasive ventilation
ALS
Lung disease during sleep
Weakened bulbar muscles can cause closing of the airway
Nerve and muscle functions relax during sleep causing underventilation
• With complaints of morning headaches, lethargy,
and SOB
Early recognition of weakening muscles during REM sleep by:
•
PSG
•
Overnight oximetry
Living with ALS: Adapting to Breathing Changes, 1997, ALS Assoc.
AAN practice parameters
Early indications of respiratory insufficiency
• Dyspnea on exertion
• Supine dyspnea
• Fatigue
• Disturbed sleep
• Morning headaches
Noninvasive ventilation should be initiated with the onset of symptoms
AAN practice parameters
NIV benefits to the patient
• Improves the symptoms of hypoventilation
• Improves quality of life
• Increases survival by treating the respiratory
insufficiency
Allows for decision making on more advanced care
AAN practice parameters
Recommendations
• Be vigilant for hypoventilation symptoms
• Offer noninvasive ventilatory support
• Offer invasive ventilatory support
• Respect the right of the patient to refuse therapy
• When withdrawing ventilation, relieve dyspnea and
anxiety
• The committee strongly supports the use of mechanical
insufflation-exsufflation in patients with DMD
• Patients with DMD should be taught strategies to improve
airway clearance and how to employ those techniques early and
aggressively
• Use assisted cough technologies in patients whose clinical
history suggests difficulty in airway clearance, or whose peak
cough flow is < 270 l/min and/or whose maximal expiratory
pressures are < 60 cm H2O
Quality of life
Study aim
Initiation of NIV earlier than current “standard of care” may provide
additional benefits in terms of respiratory function and quality of
life.
Jackson et al. A Prospective Evaluation of Pulmonary Function Studies and Symptoms of Hypoventilation in ALS/MND
Patients. J Neurol Sci 2002;1610
Quality of life
13 patients
7 received early NIV intervention, 6 received NIV per
existing standard of care
FVC was done in sitting or supine position
Pulse oximetry was performed
Quality of life
Conclusions
• To detect respiratory insufficiency, O2 saturation of
less than 90 percent is a more sensitive indicator than
FVC of 70 percent
• Early intervention with NIV increased “vitality”
subscale of the SF-36
• NIV earlier than current practice may result in
improved QOL
BiPAP in OSA with other co morbidities – AVAPS
NeuroMuscular
Disorders
AVAPS
OSA
COPD –
Overlap
Obesity HypoVentilation
AVAPS
AVAPS
• AVAPS is the treatment of choice for
patients presenting with chronic
respiratory disease as well as a
mixed SDB pathology.
• AVAPS automatic ventilation modality
allows normalizing ventilation with a
target exhale Vt whereas the EPAP
level maintains the UA open (treating
OA).
• The settable backup rate and the rise
time allows better control and
adaptation to different types of
patients.
AVAPS Algorithm
BiPAP Synchrony AVAPS
10 PM
IPAP
Max.
IPAP
Min.
EPAP
Target
Vt
7 AM
• AVAPS is a ventilation device for
patients with respiratory insufficiency
• ST-T-CP modes can treat central
apneas
• AVAPS: Pressure Support adjustment
looking at average tidal volume
– PS increase or decrease maximum
speed is 1 cm H2O/minute
– AVAPS allow maintaining a target
tidal volume
Patient tracing over time
• Automatically adjusts IPAP to guarantee a target tidal volume
S/T compared to S/T + AVAPS
Pressure support is progressively decreasing:
• AVAPS follows patient’s needs and disease progression
• The patient is getting better
Clinical benefits of AVAPS
• Guarantee of ventilatory support during progressive
ventilatory changes of the patient
• Guarantee of ventilatory support during positional
changes during sleep
• Provides the assurance of a tidal volume within a
bilevel system
• Alarms to indicate that tidal volume is not being
maintained
Summary
• Secretion mobilization techniques assist the
mucociliary escalator, but they do not assist
cough
• Cough is the principle mechanism for clearing the
airways
• Patients who have an impaired cough mechanism
require secretions to be removed
• Initiation of NIV may improve quality of life and
symptoms of hypoventilation in patients with
neuromuscular disease