Diaphragmatic Pacing

9th Annual Advocate Injury Institute Symposium
Trauma 2012: Prepare for the Worst and Hope for the Best!
Innovations in SCI Recovery: Diaphragmatic Pacing
Lisa F. Wolfe
Associate Professor of Medicine
Northwestern University Feinberg School of Medicine
Conflict of Interest Disclosures
SPEAKER
1. I do not have any potential conflicts of interest to disclose, OR
X
2. I wish to disclose the following potential conflicts of interest:
Type of Potential Conflict
Details of Potential Conflict
Grant/Research Support
ResMed
Consultant
Respironics, Hill-Rom
Speakers’ Bureaus
Financial support
Other
X
1. 2. 3. 3. The material presented in this lecture has no relationship with any of these potential conflicts, OR
4. This talk presents material that is related to one or more of these potential conflicts, and the following objective references are provided as support for this lecture:
Overview
• Respiratory challenges of Spinal Cord Injury
Respiratory challenges of Spinal Cord Injury
• History of Pacing
• What should health care providers know
Wh t h ld h lth
id k
–
–
–
–
–
–
–
What are the currently available devices
How do the devices work
Surgical issues
Anesthetic issues
Post op care
Post op care
Training
What to look for at a clinic visit
• How to choose pacing as the best option
– For your patient
– For our community
• QoL – Speech, Smell etc.
Cervical Spinal Cord Injury • Incidence of long‐term ventilator‐assisted SCI g
patients increased from 11 419 cases per year in 1990 to 43 700 cases per year in 1998
– No incidence studies of SCI in the U.S. since the 1990's
• 200–400 SCI per year (US) are vent dependent
• 8 Billion per year is spent on SCI care in the US
• After the first year of injury, respiratory After the first year of injury, respiratory
complications are the #1 cause of morbidity and y
mortality in SCI
Carter, R.E., 1987. Paraplegia 25, 86–91.
Chest 2005; 128: 3937–3954
SCI and Respiratory Function
SCI and Respiratory Function
Impact of Level of Injury
Winslow C, Am J Phys Med Rehabil 2003;82:803–814.
Goals:
Long term ventilation in the home
Long term ventilation in the home
Ventilator‐ Assisted Individual
Ventilator
Assisted Individual
The Goals of VAI
• VAI’s are a class of patients that have 1) To sustain and extend pulmonary disability but have a goal life
of living full and active lives in a 2) To enhance the community based setting.
quality of life
3) To reduce morbidity
3) To reduce morbidity
• VAI
VAI’ss utilize ventilators to liberate
utilize ventilators to liberate
them allowing a life where the patient 4) To improve or sustain physical and is more independent:
– Directing their own daily care – Directing their own healthcare choices
– Setting and achieving personal / life goals
g
gp
/
g
AARC GUIDELINE: LONG-TERM INVASIVE MECHANICAL VENTILATION IN
THE HOME
RESPIRATORY CARE • AUGUST 2007 VOL 52 NO 1
psychological psychological
function
5) To provide cost‐
effective care
effective care
Why is long term MV a failure in SCI ?
Why is long term MV a failure in SCI ?
Needing
ga
vent costs
up to100K a
year and 2-3
million over
a life time
The greatest impact on reduced life expectancy for this population is pneumonia
and septicemia
septicemia. The need for mechanical ventilation drives up the costs and drives
down life expectance.
Needing a
vent reduces
life
expectancy
Topics in Spinal Cord Injury Rehabilitation Volume 16 Number 4 in 2011.
SCI Challenges
SCI Challenges
•
•
•
•
Costs
Long Term Care
g
Communication
Quality of life
Quality of life
History/ Options
• May 1971 ‐ First clinical use phrenic pacing
• All devices require functional phrenic nerves
• There are two types of devices:
– Conventional Phrenic Nerve Pacing • Avery Laboratories(Commack, NY, USA)
– Phrenic Nerve Pacing with intramuscular diaphragm electrodes electrodes
• Synapse BioMedical (Oberlin, OH, USA)
– Intercostal muscle pacing
• Not clinically available in the US
Glen WW, Annals of Surgery. 183(5):566‐77, 1976 May.
A.F. DiMarco / Respiratory Physiology &Neur obiology 147 (2005) 273–287 Conventional Phrenic Nerve Pacing • Phrenic nerve electrodes
– Cervical
• May get a smaller VT due to inability to get all roots
• Neck movement may Neck movement may
increase risk of nerve/ electrode injury
• May get shoulder or neck May get shoulder or neck
contraction
– Thorax
• Preferred approach
A.F. DiMarco / Respiratory Physiology &Neur obiology 147 (2005) 273–287 A.F. DiMarco / Respiratory Physiology & Neurobiology 169 (2009) 200–209
Conventional Phrenic Nerve Pacing • What equipment is needed?
– External • power supply and pulse l
d l
generator (D)
• radio‐frequency transmitter (C)
• antenna wires
– Internal
• Electrodes (A)
• Connectors
• Radio‐frequency Radio frequency
transmission receiver (B)
Journal of Pediatric Surgery (2008) 43, 792–796
Conventional Phrenic Nerve Pacing
Cardiology 2010;116:98–100
• How does it work?
– Transmitter generates a radio‐frequency signal, which is inductively coupled to the implanted receiver using antenna wires
– The radio‐frequency signal is converted by the receiver, to The radio frequency signal is converted by the receiver to
an electrical signal, which is transmitted to the electrode.
Phrenic Pacing:
intramuscular diaphragm electrodes
• Laparoscopic
Laparoscopic placement placement
• The phrenic nerve in diaphragm is mapped
• The Peterson Electrode is needles into the muscle
The Peterson Electrode is needles into the muscle
AJRCCM Vol 166. pp 1604–1606, 2002 and Surg Endosc (2009) 23:1433–1440
A.F. DiMarco / Respiratory Physiology &Neur obiology 147 (2005) 273–287
The Operation: Sti l ti th Di h
Stimulating the Diaphragm
•
Twitch versus burst stimulation patterns
Twitch versus burst stimulation patterns. –
–
Mapping diaphragms involves a single twitch stimulation with quantitative measurement of abdominal pressures and qualitative assessment of diaphragm contraction. If there is a partially denervated diaphragm a twitch will not give a consistent abdominal pressure pressure
• a burst of 1 s will allow a qualitative assessment of diaphragm contraction
Ondres, PR Surg Endosc (2009) 23:1433–1440
The Operation: Stimulating the Diaphragm
One electrode anterior diaphragm One electrode posterior diaphragm
Electrodes right diaphragm
Phrenic Pacing:
intramuscular diaphragm electrodes
• Anterior and posterior branches of the phrenic are isolated and fitted with electrodes.
• Four leads and a ground F
l d
d
d
wire are tunneled to a single point on the
single point on the abdomen to attach the electrical stimulator
AJRCCM Vol 166. pp 1604–1606, 2002
Placement of Pacer: Surgical issues
• Good safety record
– No reported mortality
N
d
li
– Surgery can be done on an out patient basis
– With DPS system and a laparoscopic approach less surgical time, and reduced risks
• Success
– Intra‐operative testing for the DPS device
– Early placement improves success
J Thorac Cardiovasc Surg 2011;142:378-83
Anaesth Intensive Care 2010; 38: 740-743
Placement of Pacer: Surgical issues
Placement of Pacer: Surgical issues
• The
The laparoscope for laparoscope for
pacing may incorporate other procedures:
– PEG take down
– Gastrostomy placement
• Challenges
– Adhesions can be a technical iss e
technical issue
– Pneumothorax is common but usually not y
significant because these are Capnothorax
Ondres, RP Surg Endosc (2009) 23:1433–1440
Placement of Pacer: Anesthesia
• Induction:
– Narcotic
Narcotic in combination in combination
with Propofol
– The addition of inhalational agents is OK
– No muscle relaxants
– Larger tidal volumes to L
id l l
avoid atalectasis ( 8‐10 cc/ kg) • Monitoring:
– Optimum placement of the stimulator best guided by the P/V loops ggenerated by modern y
anesthesia machine versus measuring intraperitoneal pressure
intraperitoneal pressure changes.
• Follow with ETCO2 to avoid over ventilation 1) Schmiesing, CA Journal of Clinical Anesthesia (2010) 22, 549–552
2) http://www.draeger.com/media/10/08/41/10084127/rsp_curves_and_loops_booklet_9097339_en.pdf
Electrode Characterization:
Assessment 4‐6 hours post op
h
• Setting optimized for each patient
• Caregiver trained in working system and recording data
• Control options for breathing
–
–
–
–
–
Amplitude
Frequency
Rate
Pulse Width
Pulse Modulation
• Programmed
Programmed to provide a stimulus that would provide a tidal to provide a stimulus that would provide a tidal
volume of 15% over basal needs.
• Initial applied stimulation is 20 (Hz). Inspiratory time = 1.1 seconds; RR = 10 ‐12 based on patient comfort and optimization of speech.
Onders, RP The Journal of Spinal Cord Medicine Volume 29 Number 2 2006
Maintaining the Exit Site
Maintaining the Exit Site
• Clean
Clean site with alcohol
site with alcohol
• Cover with guaze
Skin bandage changed
• Skin bandage changed weekly
http://www.kingswayrx.com/
Intramuscular Phrenic Pacing
Intramuscular Phrenic Pacing • Diaphragm conditioning is needed for all devices
for all devices
• Settings to augment Vt
– Stimulus amplitude (mA), Stimulus amplitude (mA)
– stimulus frequency (Hz),
– pulse width (ls), pulse width (ls),
• Typical Settings in SCI:
–
–
–
–
–
Stimulus amplitude: 25 m amps
St
u us a p tude 5 a ps
Pulse width: 150 m sec
Frequency: 20
BPM: 12
A.F. DiMarco Resp Phys &Neurobio
Ti : 1.0
147 (2005) 273–287
Type I (slow)
•
•
•
•
•
•
Smaller
M
More extensive vascular supply
t i
l
l
Large amounts of mitochondria (oxidative metabolism)
Large amounts of myoglobin (for oxygen bi di
binding and storage)
d t
)
Fatigue slowly
Stain dark with acid ATPase or NADH
Type II (fast)
•
•
•
•
•
•
Larger
Extensive sarcopalsmic reticulum (for rapid calcium release)
Large amounts of glycolytic enzymes (for rapid energy release)
(for rapid energy release)
Less extensive blood supply (anaerobic metabolism)
Fatigue quickly
Stains dark with alkaline ATPase
ATPase, pH 9.4: Type 1 fibers (light) and type 2 fibers
Type 1 fibers (light) and type 2 fibers (dark) are easily distinguished and have a random distribution
Thanks to Jeff Allen MD
http://missinglink.ucsf.edu/
Muscle Fibers:
Muscle Fibers: Model of a healthy diaphragm
y p g
• Eupneic breathing activates slow‐twitch fibers onlyy
• Sneezing and coughing activates fast‐twitch fatigable motor units • In neuromuscular disease the curve would be shifted to the left.
C.B. Mantilla, G.C. Sieck / Respiratory Physiology & Neurobiology 179 (2011) 57– 63
Skeletal
Muscle
Normal diaphragm
p g muscle:
1) Much larger size and # of
slow twitch fibers to help
support diaphragm nonfatigue ability
Diaphragm under stress:
1) Fast fibers are more
plentiful but smaller in size
Take home message:
1)
Cross-sectional areas of diaphragm muscle. From control and an
organ donor
2) Fibers from donor are smaller
smaller.
3) Fibers reacting with the antibody appear orange–red
4) open circle, slow-twitch fibers
5) open square, fast-twitch fibers.
Levine S, et al. N Engl J Med 2008, 358:1327-1335.
A diaphragm under stress will
have fewer slow fibers and
easily fatigue
– IE will be unable to
generate force after
repetitive stimulus.
Intramuscular Phrenic Pacing
Intramuscular Phrenic Pacing • A conditioning period is needed – esp. to avoid fatigue
• Adding anterior and posterior fascicles improves VT
q
g
• VT is adequate and after conditioning is better maintained.
DiMarco, A. Am J Respir Crit Care Med Vol 166. pp 1604–1606, 2002
Conditioning the Diaphragm at Home
g
p g
• Diaphragm needs to regain strength
• Conversion of fast twitch glycolytic (Type IIb) to slow C
i
ff
i h l l i (T
IIb)
l
twitch oxidative (Type I) • Patient train at own pace
Patient train at own pace
• Increase length of sessions as tolerated
Passy‐Muir
Muir valve eating and sleeping
valve eating and sleeping
• Passy
• Using system continuously > 4 hrs then can use it at night
• Devices reprogrammed as needed
Phrenic Pacing:
L
Long term follow up
t
f ll
• What you need to know when a patient shows up with a pacer:
i
h
ih
– For routine clinic appointments:
• Measure
Measure FVC and wire integrity
FVC and wire integrity
• Find out how many hours a day the patient usually paces and try to stay on schedule
– In the acute care setting
• The device has a fixed MV so when needed switch to mechanical ventilation
• Turn the pacer OFF when MV is needed for ALI/ Sepsis
When is
Wh
i
pacing the
best
therapeutic
p
option?
E A Edwards Arch Dis Child 2004;89:251–255.
Pacing is not for everyone
•
•
•
•
•
•
Require 24 hour ventilation*
Intact phrenic nerves
h
Intact diaphragm
Normal lung function before injury
Good cognitive function
Good cognitive function
Supportive team – Enlightened insurance company
E li ht
di
– Personal care assistance
– Physicians
Oda T et al Surg Res 1981;30:142-53.
Phrenic Nerve Testing
Phrenic Nerve Testing
• Diaphragmatic
Diaphragmatic compound muscle potential versus MVV or compound muscle potential versus MVV or
FVC
• There was significant negative correlation between PFTs and latencies of DCMAP.
dl t i
f DCMAP
Sathyaprabha TN, Acta Neurol Scand. 2010 Jun;121(6):400-5. Epub 2010 Jan 12.
When to asses the need for pacing?
• No clear answer – Th
The issue not i
t
addressed in trials
• We
We know that pacing know that pacing
can be successful even many years after injury but there are costs
– Lost time to Rehab
– Ability to wean 24 hours?
Onders, RP J Spinal Cord Med. 2007;30:S25–S29
Making the decision to pace / SCI?
Making the decision to pace / SCI?
• Therapy for hypoventilation– What does hypoventilation look like clinically?
– Apnea awake and alert
• C1‐C3 injuries that have 24 hour vent dependence
C C3 ju es t at a e
ou e t depe de ce
– Hypercapnea
– Atelectasis
• Pacing
Pacing is more effective then NIV at recruitment of posterior and is more effective then NIV at recruitment of posterior and
basilar lung segments
– Frequent chest infections
• Augmentation
Augmentation of tidal breathing improves peak cough flow even if of tidal breathing improves peak cough flow even if
there is no assistance to expiratory muscle function
– Weak speech
• Dysfunctional for augmentative technology Dysfunctional for augmentative technology
• Call for help
R. Onders Surg Endosc (2007) 21: 475–479
D.R. Gater, Jr. et al. NeuroRehabilitation 28 (2011) 231–24
A Esclarín Paraplegia (1994) 32, 687–693
Costs
• Esclarin– Spain:
– Pacer patients left the hospital sooner 370 vs 569
– 4 hours per day less RT time
• Less suctioning and lower maintenance
– Pacer itself is more expensive then a vent (32,500 vs 16,456) BUT the recurring are less (438 vs 16 456) BUT h
i
l
(438
1200)
Costs
• Hirschfeld – Germany:
– Rehab stay the same for MV and PP (249 vs 290)
– For in‐patients less nursing time was needed • Savings of 10,950 euro/yr
– The higher cost of the first year was equaled by savings after year three
i
f
h
• This was based on supply and personnel costs only
• If the cost of admission for infection is counted in the If the cost of admission for infection is counted in the
cost difference is made up in one year
Spinal Cord (2008) 46, 738–742
Respiratory infections in SCI:
MV vs Pacing
• Spanish retrospective study AstroStim pacer.
• MV –SCI patients 190‐2000 days (630)
MV SCI patients 190 2000 days (630)
• Pace –SCI patients 185‐3348 days (1100)
Costs
• Intramuscular Pacing on the cheap:
– Pacer placed as part of a single out patient Pacer placed as part of a single out patient
procedure
– Home based diaphragm training can begin after Home based diaphragm training can begin after
two weeks of usual home care
– With the use of home based pulse oximetry and p
y
nursing aids, home based weaning has been shown to be safe and effective.
– The cost of the device and the parts is less for intramuscular as compared to traditional phrenic nerve pacing
J Spinal Cord Med. 2007;30:S25–S29
Costs: My Assessment
Costs: My Assessment
Things that are of low impact
g
p
Trach
Speaking valve
HME
Battery
T bi Ci i
Tubing Circuits
Chair adapters
Electrical Power
Electrical Power
Pace
MV
Yes
Yes
No
Yes
No
Yes
None
Two
O /12
One/12 mo
12/12 mo
12/12
None
Yes
None
High
12/12
Yes
Yes
No
One
12/12
12/12 mo
Yes
Medium
Costs: My Assessment
Things that are of high impact
P
Pace
MV
12/12
Ventilator
One
Two
One
DME Costs
DME Costs
None
High
High
Care Givers
Care Givers
Anyone RT/RN
RT/RN** RT/RN
RT/RN**
After the critical care component of SCI:
Living
g well, improving
p
gq
quality
y of life with a SCI
Mortality benefit of pacing in SCI
• Prospective follow up of 32 pt’s in each grp.
Spinal Cord (2008) 46, 738–742
Qol in Pacing for SCI
Qol in Pacing for SCI
• Breathing feels more comfortable
Breathing feels more comfortable
• Reduces sound
– Blower
– Alarms
• Improved confidence in public
p
p
– No tubing
– No trach
– No obvious device
Brown, R. 2006. Respir. Care 51, 853–870.
Speech: on mechanical ventilation
• Challenge of leak speech
– Speaking during inhalation
– Unstable ventilation
– Failure to provide speech p
options
– Volume to low
CHEST 2003; 124:1512–1521
Cuffless Inhalation
Cuffless Exhalation
Cuffed
Speaking valve/
fenestration
Speech: with pacing
Speech: with pacing
• Speech during expiration while pacing
Speech during expiration while pacing
– Trach capped and negative pressure = “normal” speech
• In one study there was no difference between Pacing and MV for the “ability”
Pacing and MV for the ability to talk to talk
• The quality of speech significantly better with P i (P 0 0005)
Pacing (P= 0.0005)
Spinal Cord (2008) 46, 738–742
Speech with pacing in SCI
Speech with pacing in SCI
• Speech
Speech is present in is present in
those with MV and Pacing • Speech is more intelligible for those using pacers
Pacer rating:
Lowest score 3
Average score 6 (5.25–6)
MV ratings
Lowest score 1
Average score2 (3.5 (2–5.75))
Pacing improves sense of smell
Pacing improves sense of smell
• The
The use of negative use of negative
pressure ventilation combined with the ability to cap the trachesotomy allows air fl t
flow to return to the t
t th
nose
• The return of sense of The return of sense of
smell improves quality of life
of life
Eur Respir J 2009; 34: 365–370
1: anosmia; 2: severe microsmia; 3: moderate microsmia;
4: mild microsmia; and 5: normosmia.
Can the trach to come out?
When keeping the trach in:
• PSG with trach closed
– Always keep cuffless or with the balloon down for
the balloon down for safety/communication
– Trach can be opened to treat upper air way obstruction
upper air way obstruction
– Trach can be opened if need for hydration
• PSG
PSG to confirm adequate t
fi
d
t
ventilation
When to take out trach?
When to take out trach?
•
•
•
•
•
•
Alert and no sedating medications
Afebrile with normal wbc
PaCO2 40 mmHg or less
Oxyhemoglobin saturation baseline (SpO2) ≥95% over 12 hours in ambient air
All oxyhemoglobin desaturations below 95% reversed by MAC
CPF, unassisted or assisted, exceed 2 7 l/s with the fenestrated
2.7 l/s with the fenestrated tracheostomy tube capped or the tube out and the stoma covered
– After “conditioning” this may confirm adequate stability Bolikal et al The Journal of Spinal Cord Medicine 2012 VOL. 35 NO. 3
Qol in C‐2
Qol in C
2 SCI Pacing vs MV
SCI Pacing vs MV
• Patients with Pacers appear more likely to remain active.
Spinal Cord (2008) 46, 738–742
Pacing and quality of life
Pacing and quality of life
• Patients & Caregivers agree they prefer Pacing vs MV.
P ti t & C
i
th
f P i
MV
Qol in Pacing for SCI
Qol in Pacing for SCI
• Mobility:
– Easier transfers
• Including toileting options
– Increases option for daily activities
• Rehab
• Employment
Elefteriades, J.A., et l 2002. Pacing Clin. Electrophysiol. 25, 897–906.
The Hurricanes of 2005 and Ventilators: The Benefits of the DPS System
h
fi f h
SS
• Loss of electricity alone no longer a concern
Loss of electricity alone no longer a concern
• Evacuation easier
•
•
•
•
Less packing
Less
packing
Transportation Easier
Temporary Housing
Temporary Housing Less noise and space in crowded facilities
Lets put a real face on the problem
Lets put a real face on the problem
A travel “Story”
A travel Story
• Goal
Goal since injury was to since injury was to
solo sail again
• Developed sip and puff p
p
p
sailboat
• Cannot sail on ventilator‐ extension cord problem
Thanks to MaryJo Elmo Case Western University
MaryJo.Elmo@UHhospitals.org
Easier to Get Married off the Ventilator
l
Thanks to MaryJo Elmo Case Western University
MaryJo.Elmo@UHhospitals.org
Transferring is easier with a Pacer
Transferring is easier with a Pacer
Thanks to MaryJo Elmo Case Western University
MaryJo.Elmo@UHhospitals.org
You cannot skydive on a ventilator!
You cannot skydive on a ventilator!
Thanks to MaryJo Elmo Case Western University
MaryJo.Elmo@UHhospitals.org
Summary
• Treatment of C
Treatment of C‐SCI
SCI with a Pacer instead of MV
with a Pacer instead of MV
– Significantly reduces airway infections,
– Reduces costs for single use airway equipment,
Reduces costs for single use airway equipment
– Improves the quality of speech and olifaction
– Improves patients and care giver quality of life,
I
ti t
d
i
lit f lif
– Probably reduces mortality and prolongs life,
Spinal Cord (2008), 1–5
Phrenic Pacing
Phrenic Pacing
•
•
•
•
Indications
Spinal Cord Injury
Amyotrophic Lateral Sclerosis
Amyotrophic Lateral Sclerosis
Central Congenital Hypoventilation Syndrome
Newer possibilities:
– Post operative phrenic injury
– Idiopathic phrenic paralysis
Idiopathic phrenic paralysis
• Parsonage Turner
– Prevent disuse atrophy of the diaphragm during prolonged mechanical ventilation
prolonged mechanical ventilation
FDA approved indications
Requirements
• Intact Phrenic Nerve
• Good Good
cognitive function
• Good family support
ALS: Background
ALS: Background
• Jean-Martin
Jean Martin Charcot described ALS in
1869.
• Most are between 40 and 70 years of
age although the disease can strike at
age,
any age.
/
• Incidence/Prevalence
– More than 5,600 Americans are diagnosed
with ALS each year
– 2 new ALS cases per 100,000 people
– Approximately 35,000 people at any given
time are living with ALS in the United
States
– 6-8 people per 100,000 population
Data from the Les Turner ALS foundation
Cystic Cystic
Fibrosis:
‐1000 new 1000
diagnosis/yr
‐1 in 3000 European descent
‐30,000 A
American i
living with CF
ALS: Definition
ALS: Definition
Criteria For the Diagnosis of ALS
El Escorial World Federation of Neurology
El Escorial World Federation of Neurology
Criteria for the diagnosis of Amyotrophic Lateral Sclerosis
The diagnoses of ALS requires the presence of:
1) Signs of lower motor neuron (LMN) degeneration by clinical, electrophysiological or 1)
Signs of lower motor neuron (LMN) degeneration by clinical electrophysiological or
neuropathologic examination,
2) Signs of upper motor neuron (UMN) degeneration by clinical examination
3) Progressive
3)
P
i spread of signs within a region or to other regions, together with the absence of
d f i
ithi
i
t th
i
t th
ith th b
f
A) Electrophysiological evidence of other disease processes that might explain the signs of LMN and/or UMN degenerations
B) Neuroimaging evidence of other disease processes that might explain the observed clinical and electrophysiological signs.
4) Not included:
A) Cognitive issues common but not included
Fronto Temporal Dementia
http://www.alsa.org/
NIV in ALS: Benefits
NIV in ALS: Benefits
• Survival
– Best RCT
– Median survival benefit of 205 days y
(p=0∙006)
– The use of NIV improves survival but is a challenge for those with bulbar disease.
– The improvement in survival is greater then that seen with Ril l
Riluzole
Total Group
Total Group
Limb Limb
Onset
Bulbar
Bourke, SC Lancet Neurol 2006; 5: 140–47
Pacing in ALS
Pacing in ALS
The Trial
Why use pacing in ALS?
Why use pacing in ALS?
• Inclusion:
– FVC >50%
• Design cross over
– Every pt serves as their own control
– An FVC needed to stay >45% after 3 An FVC needed to stay >45% after 3
months to allow for implantation
• Methods
– Pacer use 5 times a day for 30 mins
• Assessment
– Lung
Lung function etc measured every 3 function etc measured every 3
months
Onder, R. Surg Endosc (2009) 23:1433–1440
• Mortality is due to respiratory failure
• Electrical stimulation can help to over
can help to over come the deficits from UMN disease
• The greatest failure in NIV is from bulbar disease. Pacing
disease. Pacing avoids the upper airway
Pacing in ALS
Pacing in ALS
The Trial
• Results:
– DPS can convert fast‐twitch glycolytic (IIb) to functional slow‐twitch oxidative muscle (I) u ct o a s o t tc o dat e usc e ( )
fibers; – DPS improves posterior lobe lung ventilation; – DPS increases lung compliance, leading to decreased work of breathing; – DPS to improve nighttime ventilation. The ALS diaphragm is The
ALS diaphragm is
much weaker ; the
denervated areas can be seen as the pale radial bands
• It has been found that ALS patients develop central hypoventilation that can be overcome with night DPS
hypoventilation that can be overcome with night DPS use.
– Average rate of decline in FVC of 0.9% per month from the pre‐implantation decline of 2.4% a month, – Extrapolates to an additional 24 months of ventilator‐free survival.
Onder, R. Surg Endosc (2009)
23:1433–1440
NIV + DPS in ALS: Benefits
•
Adding NIV to nocturnal Pacing increases survival in ALS patients from:
– NIV + DPS vs NIV alone (months) 20.9 ± 4.9 VS. 11.9 ± 2.2 p < 0.001
Onders, RP. Amyotrophic Lateral Sclerosis 2010;11:137
NIV + DPS in ALS: How to’s
• How to make it work
How to make it work
• How to monitor
How to monitor
– Set the NIV as a slave to the pacer
• Use a standard ST device
• Set the rate 1‐2 less then the back up rate of the pacer (12 BPM)
• Set the Ti time equal to the pacer (1.1 sec)
– The download soft ware from the NIV will allow for adequate monitoring
– Augment Tidal volume with increases in IPAP
with increases in IPAP
– Augment rate by turning up the rate of the pacer
– Occasional additional overnight oximetry may be helpful
be helpful
Onders, RP. Amyotrophic Lateral Sclerosis 2010;11:137
NIV + DPS in ALS: How to’ss
NIV + DPS in ALS: How to
Slide thanks to Dr. onder
Summaryy
• Respiratory pacing systems can be used to:
– A
Augment ventilation in the setting of il i i h
i
f
neuromuscular disorders
– Augment diaphragm muscle strength –
A
t di h
l t
th IE training IE t i i
effect
• The
The use of pacing devices is most well se of pacing de ices is most ell
accepted and addressed in SCI but new indications such as ALS are on the horizon
indications such as ALS are on the horizon
Thank‐You