Download Respiratory Muscle Performance in Normal Elderly Subjects and

Respiratory
Muscle Performance
in Normal
Elderly Subjects and Patients with COPD*
i:
Nancy
Morrison,
Lindsay
We studied
Judy
M.D.;t
Dunn,
M.Sc.;
and
the reproducibility
in normal
elderly
subjects
Richardson,
Richard
of tests
and
Dip.
L. Pardy,
PT;
MB.
of RM performance
compared
their
are
that
of patients
with COPD.
The RM strength
was
as MIP and MEP.
The RM endurance
was
measured
using a two-minute
incremental
threshold
loading
test. The max load, the average
Ppk as %MIP at max load
and the Pmean
at max load were taken as measures
of
respiratory
muscle endurance.
The MIP, but not MEP, was
less in COPD
patients
than in normal
subjects
(p<O.O5).
There
was a small increase
in between
visits, in MIP in the
normal subjects.
All measures
of RM endurance
were much
lower
in the COPD
group
than in the normal
elderly
with
measured
espiratory
terms
muscle
pressures
Black
muscle
of strength
and
Hyatt.’
RM
different
is
as well
it
subjects.
The
respiratory
those
most
frequently
reported
of RM
endurance
incorporates
loading
as the
devices.
time
pattern
and
pressure
muscles
may
substantially
load is tolerated.58
breathing
pattern
was
load
tolerated
indicate
was
tolerated
by
alter
the
It is apparent
and
fixing
the
pressure
generation
by resistive
complex
than
measured
for a specific
that variability
generation
endurance
test more
is
for
inspiratory
necessary
loading,9’0
previously
to
between
be
be
tolerated
exhausting
ability
to add
with
2-mm
resiseither
or as the
the
University
of
British
Columbia
in normal
we
determine
RM
strength
the
and their
performance
RM
times
the
duration
to establish
for 10 mm
if the test
of the
a load
which
was quite
long.
were
used
for
This
other
externally.
Martyn
et al’s started
loads.
This
reproducible
ance
with
diseases
affecting
are elderly.
Therefore,
normal
and
values
the
for
2-mm
respiratory
in this study
elderly
subjects
incremental
for
loading
test,
reproducibility.
In addition,
we compare
RM
in the normal
elderly
with RM perform-
in patients
who
have
COPD
15
this
METHODS
and
Research
who
normal
Laboratory
Vancouver,
tCanadian
and Physiotherapy
Department,
St. Pauls
Hospital,
British
Columbia,
Canada.
Lung Association
Research
Fellow
Supported
by British
Columbia
Health
Care Research
Foundation
and B.C. Lung Association.
Manuscript
received
February
16; revision
accepted
May 10.
Reprint
requests:
Dr Morrison,
Pulmonary
Research
Laboratory,
St. Thulc Hospital,
Vancouver,
B. C. , Canada
V6Z 116
90
the
rest
young
inspiratory
Pulmonary
at high loads
(requiring
near MIP),
and allowing
gies for managing
progressively
greater
test was found to be relatively
simple
and
Volunteers
*From
was
to an
taken
weights
a particular
makes
device.
muscles
applied
low inspiratory
loads
which
were
increased
at
intervals
so that subjects
could
develop
strate-
the
evaluate
of meas-
loading
inspiratory
of weight
of ten
time
Many
patients
muscle
function
which
reported.
on the
amount
loads
overall
a method
a threshold
than normal
subjects.”’2
In our laboratory,
Martyn
et al’s used
a device
similar
to that of Nickerson
and Keens”
but with the
assess-
that regulating
breath-by-breath
designed
using
load
by the
time.
However,
in breathing
time
Keens”
endurance
the
could
could
in normal
method
Endurance
a particular
maximum
load
recent
reports
obtained
and
RM
test,
reduced
airway
conductance
is a feature
is difficult
to compare
MSVC
results
in
with
time
periods
endur-
and endurance
and patients
decreased
RM
subjects
= maximum
sustainable
ventilatory
capacity;
max
maximum
weight
lifted for 2 mm; Ppk
peak inspiratory
pressure;
Pmean
mean
mouth
pressure;
Ttot
total
for each breath;
SIP
sustainable
inspiratory
pressure
intake
valve.
By starting
generation
of pressures
conduc-
muscle
MSVC
load
mouth
The
pressure
determined
of RM
airway
elderly
94)
Nickerson
to
test
that (1) RM strength
normal
in
COPD,
(2) that COPD
subjects
have
strength
and endurance
compared
with normal
elderly
subjects,
and (3) that in COPD
subjects
RM endurance
is
compromised
more than RM strength.
(Chest
1989; 95:90-
uring
MSVC
is the highest
for 15 mm.2 However
reduced
as by reduced
of patients
group
by
measure
reproducible
with
in
of methods
that
they
likely
RM . One
of the
is decreased
this
tive
a variety
is the MSVC.
The
that can be sustained
ance.
Since
of COPD,
ment
are
It
capacities
MSVC
tance
There
endurance.2
endurance
ventilation
the
performance
is measured
and endurance.
Respiratory
strength
can be measured
using MIP and MEP
at the mouth,
according
to the method
of
assess
We conclude
(p<OO5).
performance
who
had
had
Each
tests
had
Respiratory
formed
gave
the
with
COPD
Paul’s
history
patients
Hospital,
no previous
Muscle Performance
of respiratory
or cardiac
examination,
normal
physical
the
informed
of respiratory
experience
The
no
a normal
spirometry
subjects.
St.
had
study
consent.
muscle
weighted
were
plunger
recruited
experience
in Normal
with
and
and
elderly
subjects
had
never
had
had
prior
not
apparatus.
from
Canada.
The
tests
of RM
Subjects
of normal
All eight
function
Vancouver,
Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21587/ on 05/13/2017
population
disease
ECG
the
and COPD
respiratory
eight
patients
performance.
Patients
clinic
at
chosen
Results
(Morrison et a!)
B
A
STOPPER,
TURBINE
FLOW
TRANSDUCER
PLUNGER,
TO PRESSURE
TRANSDUCER
WEIGHTS
FIGURE
ofstudies
on
All
subjects
and
FVC
Morris
these
Diagram
patients
and
were
1.
ofthreshold
previously
patients
measured
had
and
have
loading
been
spirometry
device.
published.’
measured.
expressed
as percent
pressure
The
FEy,
predicted
Peak
(from
recorded.
et alh6).
In each
group,
measured.
respiratory
The
after
maximal
near
TIC,
Hyatt.’
at the
near
RV, and
pressure
voluntary
taken
transducer
endurance
were
were
measured
maximal
the
method
was
the
and
of several
was
1400).
(Alpha
through
inspired
volume
to
Technologies,
110-500,
were
Laguna
Hills,
not
full
The
%MIP),
Predicted
imetry
Lindall
et al’
The
was
loading
plunger
and
Increased
weights
on
minute
inspiratory
transducer
were
measured
the
and
shown
Table
et al’
when
for
men
were
1-Anthropometric
Elderly
Normal
Figure
with
and
from
B of Figure
with
a
incremental
1 illustrates
an
orifice
was
using
the
cm
turbine
flow
pressures
H2O
differential
and Spirometric
Data
and COPD
Patients*
Subjects
and
max
passing
the
pass
filter
with
subjects
began
every
2 mm
which
over
load
were
the
load
until
the
could
tolerate
VT,
Vi,
for
results.
and
Ti
values
as measures
(50
subject
maximum
maximum
taken
recorded
France).
subjects
The
mouth
a time
at a low
six breaths),
weight.
were
Villiers,
in calculating
(generated
each
by
low
were
Ttot
of Ppk
(as
of respiratory
endurance.
subjects
were
monitored
Technology,
test.
Each
times
in the
Data
Analysis
to
Inspired
1 . Inspiratory
± 100
cm2.
pressure
in place.
weights
included
for
line
pressure)
Pmean
mc),
normal
with
wore
subject
morning
ear
nose
and
on separate
eximetry
clips
and
COPD
days,
(Biox
were
patient
was
week
between
one
IV, Biox-
seated
during
tested
three
tests.
the
of 6.6
increased
stopper
measured
mouth
a 2-mm
required
the
in Section
of
port
plunger
VT
at the
using
A
inspiratory
port
ventilation
measured
Section
13
weighted
the
Kory
the
endurance
threshold
from
Ppk
Pmean
The
for women.
RM
open
taken
Only
were
and
Ballain
added
CA).
breath
volume,
test,
were
continue.
recorded
muscle
were
incremental
2 mm
on
(time,
Co. , Northridge,
each
obtained
Instruments,
weights
average
CA). Maximum
ventilation
over 15 s was measured
and the highest
volume
for 12 s was used
and
expressed
as liters
per
minute.
values
2-mm
Validyne
with
a second-order
(Gould
g) and
could
measured
through
chart
the
100
a one-way
was
was
of 20 s. All signals
the
measured
The
Pmean
constant
For
Black
highest
The
45-32;
pressure
signal
inspiration,
of
(model
mouth
pressure
on a strip
of 1 s.
ventilation
No.
and
mouth
after
to
for a minimum
(Hans-Rudolph
by a turbine
strength
MEP
according
maximum
Maximal
muscle
the
expiration,
sustained
valve
and
respectively,
The
attempts
MIP
transducer
inspiratory
on
An
analysis
multiple
of variance
comparison
interactions,
groups.
for
differences
Evidence
procedures
Bonferroni
small
number
in tables
between
of group
to learn
The
repeated
procedure
used
visits
and
differences
which
visits
procedure
were
was
ofcomparisons.
and
measures
were
led
and
to
between
to multiple
are
comparison
to the differences.
as most
All values
statistical
differences
contributing
chosen
a Bonferroni
examine
appropriate
reported
for
as mean
a
± SD
figures.
RESULTS
Normal
Elderly
Subjects
Age(yr)
COPD
(n=8)
(n8)
67±4
67±8
5:3
Sex(M:F)
(cm)
(kg)
169 ± 8
71 ± 10
(% pred)
Height
Weight
6:2
171
± 7
78±13
121 ± 10
33 ± 14t
FVC
(% pred)
108 ± 9
66 ± 23t
MVV
(L/min)
121 ± 36
46 ± 18t
FEV,
MVV(%pred)
108±13
...
...
RV (% pred)
TLC(%pred)
*&Jl
values
tp<0.001.
are
mean
±
SD.
There
Patients
39±16t
204 ± 22
125±6
was no difference
subjects
weight
airflow
1). The
either
FVC
FEy,,
group
The
subjects
not
between
and COPD
patients
(Table
1). The
COPD
limitation
and markedly
MIP
from
was
less
(p<O.O5,
different
and
visit
in the
MW
were
1 to visit
3.
in COPD
Fig
the normal
patients
visit
groups
at any
increased
at visits 2 and 3 (compared
1) in normal
subjects
(polynominal
but
no difference
in COPD
in MIP
patients.
was
Although
CHEST
Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21587/ on 05/13/2017
not
2) at each
two
elderly
in age, sex, height
or
patients
had
severe
reduced
MVV (Table
than
while
visit.
in
normal
MEP
was
The
MIP
with that at visit
contrasts,
p<O.O5)
observed
in Figure
I 95
different
between
visits
2 it appears
I 1 I JANUARY,
1989
91
MEP
MIP
iTT
0
C,’
I
E
U
4)
E
2O
I
COPO
Normal
FIu’RE
2.
COPD
patients
visit
Respiratory
patients.
VIsit
I
muscle
Asterisks
compared
2
strength
indicate
with
COPD
Normal
in
that
for
a lower
normal
Visit
‘
normal
Li
3
and
in COPD
each
visit
subjects
value
of MIP
subjects
for
1’
(p<0.05).
that
the
MIP
ofCOPD
to visit 2, seven
very little from
patient
visit
the
to
64
tended
of the eight
visit to visit.
MIP increased
cm H20
on
that
1
from 30 crnH2O
on the first
visit 2. This
patient’s
values
between
visits.
For
MEP,
in either
group.
of the data for
subjects
groups
subject
the first
visit
COPD
patients
changed
However,
in one COPD
effect
was found
the consistency
in both
from
except
no definite
This
visits
for one
elderly
eO
to
all
endurance
in Figure
max
04
I
load, Ppk/
3. All three
U
0
25
x
20
0
the
at each
measures
addition,
either
The
elderly
in COPD
visit
patients
(p<O.O5).
of endurance
there
was
no
The
in either
difference
group
for VT, Vi or Ti.
02 saturation
was higher
group
compared
with
than
mean
group
(Fig
between
0
E
0
in
0’
(p<O.O5)
in the normal
that in COPD
patients
at the
start of the endurance
test (97
94 ± 2 percent)
and at the termination
(95 ± 2 percent
vs 92 ± 3 percent).
± 1 percent
of the
Normal
-
cs
test
FIGURE
2-mm
study
strength
incremental
in naive
subjects
distribution.
MIP were
92
COPD
matched
showed
and
subjects
that
measures
of inspiratory
endurance
(as measured
by the
loading
test)
were
significantly
patients
than
in the normal
for age,
height,
weight
The
MEP,
reproducible
max load,
on repeated
3.
COPD
visiti
Respiratory
Ei
Vlslt2
muscle
endurance
for
normal
subjects
and
COPD
patients.
The top panel shows
max load in graIns;
the middle
panel,
Ppk/MIP
at iiax
load;
and the bottom
/znel,
Pmean
at max
load in cm H20.
The asterisks
indicate
that
all measures
of RM
endurance
were
less
in the
COPD
patients
than
in the normal
DiscussioN
This
muscle
15
C
0
3). In
visits
30
0
max load and Pmean
in the COPD
group
were only
40 percent
ofthose
in the normal
elderly
group.
There
was no difference
between
the three
visits for any of
subjects
less
uF,
E
-a
were
ITT
4oi.
0
in normal
values
of
measures
cOPD
normal
on visit 3.
of RM
Normal
0’
whom
MEP
increased
from 66 cmH2O
on
visit to 96 cmH2O
on visit 2 and 112 cmHO
- are shown
*
4O
in
Three
measures
MIP and
Pmean
JLTT
3o
ao
a.
visit
may be due
1 to 3 for
0
-J
x
::
the
at visit
difference
increased
mean MIP for visit 1 compared
2 but overall
there
was no statistical
to decrease
with
patients
at each
less
groups.
The
elderly
and sex
normal
elderly
visit
(p<O.O5).
MIP
increased
group
COPD
subjects.
Our results
for MIP
to previously
published
Pmean
and Ppk/
testing
in both
Respiratory
Muscle
Performance
in Normal
Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21587/ on 05/13/2017
but
on
did
in both
data.
Subjects
repeat
not
groups
For the
and COPD
visits
change
in
in
the
naive
are comparable
normal
elderly,
Patients
(Morrison
at a!)
MIP
102
was 91
29 percent
±
ofBlack
was 60
±
± 28
cmH2O
and Hyatt’).
19 cmH2O
similar
mean
subjects
to
can
other
values
in COPD
patients.
Expiratory
patients
in the
(90
to RM
This
result
muscle
percent
been
unable
similar
group.
was
MIP
The
154
mean
Braun
and Hyatt.2’
Since
percent
predicted,
but
less
than
MEP
TLC in COPD
the expiratory
to RM
The
COPD
group.
was on average
This suggests
weakness.
RM
endurance
test.
have
previous
been
of endurance,
elderly
which
subjects
was similar
found
This
of Byrd
patients
was 125±6
muscles
theoreti-
2-mm
results
incremental
on repeated
and
Mittman3
patients
prior
advantage
was
apparent
expiratory
muscles
than
in the
weaker
The
MIP
normal
2.
only
been
rather
on
subjects,
subsequent
primarily
a learning
normal
subjects
function
effect.
who
testing.
MIP
after
and
the
37
improvement.”
ofthe
COPD
difference
COPD
degree
strength,
tion.’
The
measures
and
Ppk/MIP
coordination
a 10 percent
of RM
at
max
endurance
load)
were
(max
less
the
value
with
man’s3
similar
vs 43
groups
of PpkJMIP
the
aspects
of
muscles
may
ating
pressure
against
Pmean
in COPD
of
by
in
± 22
to that
ten
percent.
of Belman
in Belman
these
two
and Mittratios
are
may
Therefore,
measure
system
fatigue
for
for
which
± 22
of endurance.
respiratory
atory
(61 percent
of the
group).
However,
similar.
patients
endurance
in
change
in
COPD,
with
of patients
were
in our COPD
MSVC/MVV
that
different
et
the first
Llmin),
suggests
retested
did not
only
Our
MSVC/MVV
very
two
patients
tests
In
mean
normal
11
to be 79
18 Llmin
comparable.
The
with
MSVC/MVV
of contracload,
lower
compared
±
directly
compared
group
(in both
Much
of this
all
that
suggests
was
(46
of the
on average,
velocity
patients
features
increase
subjects
were
on four subjects
and
Mittman3
not
they
tests.
80 percent.
the value
noted
before
and Bradley2
The MVV
different
had
previously,
function
found
to training
lung
could be explained
by the reduced
FEV,
group,
since
the MVV is determined
of airflow
limitation
and by respiratory
muscle
COPD
and
measuring
in the
any
group
was,
our
seen
only
to be
was 48 ± 16 percent
ofthe
normal
elderly
This
is very
similar
to
normal
subjects
by Leith
The
COPD
group
the
Ppk/MIP
Ppk/MIP
week
apart
and
should
not have
increase
in MIP
of the value
of the normal
units
and percent
predicted).
percent
absolute
the
the
found
in
1 to visit
with
testing
pulmonary
when
12 normal
younger
two weeks.
A third
test
show further
The MVV
was
the
in fact
visit
no experience
Although
Keens”
one
there
the
This
had
undergone
RM endurance
were
familiar
with
other
Nickerson
or that
visits
from
Since
the tests
were
spaced
took 30 mm to complete,
a training
effect.
Therefore,
suggests
true
in COPD
patients
were
normal
elderly
subjects.
increased
elderly
than
length-force
endurance
learning
trials
in
found their meas-
test with no significant
visits. In our patients
Belman
theoretic
of RM
in normal
younger
subjects
by Martyn
suggests
that
learning
occurs
during
COPD
the
with
in the normal
is not marked
had a Ppk/MIP
of 79 ± 19 percent
to the SIP max/MIP
of77 ± 6 percent
controls
that
reports
MSVC/MV\
mean
mean
either
in patients
the endurance
test of Nickerson
and
SIP/MIP
percent
was 68 ± 3 percent.
cally should
have been at a more advantageous
length
for MEP
generation
than
in normal
subjects.
The
slightly
lower
mean
MEP
in COPD
patients
than in
suggests
MEP
89 percent
ofthat
that RM weakness
in these COPD
patients.
Conversely,
the max load and
Pmean
for the COPD
patients
were
on average
only
40 percent
of values
obtained
in the normal
group
in
ure
The mean
predicted)
to those
(Fig 3).
between
is due
of normal
subjects.
After
repeated
normal
subjects,
Leith
and Bradley2
cmH2O
those
in the normal
elderly
subjects
difference
in RM endurance
greater
than the difference
in patients
with COPD
was
that in the normal
group,
only part of this decrement
There
in COPD
± 37
than
the
the two groups
was much
in RM strength.
The MIP
on average
66 percent
of
although
as noted
before,
the
predicted).
Other
investigators
also
to reproduce
the results
of Black
and
patients
However,
norma1.
and Hyatt’
for MEP
in normal
subjects.
MEP was 138 ± 65 cmH2O
(76 ± 39 percent
in COPD.
These
values
are almost
identical
of Rochester
RV
Table
1),
lung volume
were
was
elderly
subjects
Since
in a lower
strength
strength
and the normal
normal
elderly
have
would
is
COPD
MIP
in
elderly
weakness.
predicted,
absolute
muscle
± 20
for
22 percent
at a higher
±
if respiratory
reported
of the smaller
with
the normal
be attributed
elevated
(204
was measured
even
in COPD
patients
predicted).
This
weakness
was not due to malnutribody
weight
was normal).
This
patients.21’22
Only
a portion
COPD
patients
compared
was
MIP
regression
MIP
percent
± 18
which
was
equations
± SD),
(using
The
(64
inspiratory
muscle
tion (percent
ideal
very
(mean
predicted
and
different
may
not
be
lower
level
for Ppk/MIP
suggests
that the inspirquickly
when
genercompared
with sustaining
more
a load
ventilation
with unloaded
breathing.
There
are several
reasons
why RM endurance
could
be relatively
more
compromised
than RM strength
in
COPD
patients
compared
with
normal
elderly
subjects.
mum
The measurement
static contraction
versy
as
to
increased,
have been
whether
of strength
of RM fibers.
diaphragmatic
decreased
or unaffected
reports
of muscle
fiber
diaphragm
and
COPDY-27
ever,
similar
Atrophy
changes
intercostal
muscles
a maxiis contro-
muscle
mass
I 95
is
in COPD.
There
atrophy
in both the
of patients
with
would
decrease
strength.
in skeletal
muscle
have
CHEST
Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21587/ on 05/13/2017
involves
There
I 1 I JANUARY,
1 989
Howbeen
93
found
with
aging,
disuse
and
not be peculiar
to patients
with
determinants
of RM endurance
malnutrition
and may
COPD.
Whatever,
the
are more
complex
than the determinants
For
the
respiratory
of RM strength.
muscles,
four
factors
could
reduce
time:
energy
stores,
the
endurance
low rate of energy
increased
external
The
diaphragm
patients
have
bly could
Measurement
energy
biopsies
which
we did
Demand
for energy
patients,
resulting
quickly
be
than
that
by
is higher
in normal
increased
COPD
The
in COPD
of
had
compared
to reduced
11
Therefore,
a slightly
larger
(Oxygen
supply
Sa02. ) This
patients
flow and
in COPD
is dependent
could
lead
but
would
on
13
to reduced
not affect
volumes
with the
Nickerson
patients
were
working
(RV 204 ± 22 percent
normal
subjects,
which
predicted)
would
demand,
ciency
findings
of
and
decreased
in
times
increased
breathing
that both
more
in
RM
COPD
work
COPD
strength
patients.
adversely
and
Endurance
affected
than
with
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JB,
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Downloaded From: http://publications.chestnet.org/pdfaccess.ashx?url=/data/journals/chest/21587/ on 05/13/2017
Subjects
and COPD
Patients
(Morrison
et a!)