Download Pulmonary Function Tests 2


Lungs comprised of
◦ Airways
◦ Alveoli
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Weibel ER: Morphometry of the Human
Lung. Berlin and New York: SpringerVerlag, 1963
Conducting zone: no
gas exchange occurs
◦ Anatomic dead
space
Transitional zone:
alveoli appear, but
are not great in
number
Respiratory zone:
contain the alveolar
sacs
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
Murray & Nadel: Textbook of Respiratory
Medicine, 3rd ed., Copyright © 2000 W. B.
Saunders Company
Approximately 300
million alveoli
1/3 mm diameter
Total surface area if
they were complete
spheres 85 sq.
meters (size of a
tennis court)
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Inspiration
◦ Active process

Expiration
◦ Quiet breathing: passive
◦ Can become active
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IRV
VC
TLC
ERV
FRC
RV
◦ Sum of 2 or
more lung
volumes
IC
TV
RV
4 Volumes
4 Capacities

IRV
IC
VC
TV
TLC
ERV
FRC
RV
RV
Volume of air
inspired and
expired during
normal quiet
breathing

IRV
IC
VC
TV
TLC
ERV
FRC
RV
RV
The maximum
amount of air
that can be
inhaled after a
normal tidal
volume
inspiration

IRV
IC
VC
TV
TLC
ERV
FRC
RV
RV
Maximum
amount of air
that can be
exhaled from
the resting
expiratory
level

IRV
IC
VC
TV
TLC
ERV
FRC
RV
RV
Volume of air
remaining in
the lungs at
the end of
maximum
expiration

IRV
IC
VC
TV
TLC

ERV
FRC
RV

RV

Volume of air
that can be
exhaled from
the lungs after a
maximum
inspiration
FVC: when VC
exhaled
forcefully
SVC: when VC is
exhaled slowly
VC = IRV + TV
+ ERV

IRV
IC
VC
TV
TLC

ERV
FRC
RV
RV
Maximum
amount of air
that can be
inhaled from
the end of a
tidal volume
IC = IRV + TV

IRV
IC

VC
TV
TLC
ERV
FRC
RV
RV

Volume of air
remaining in the
lungs at the end
of a TV expiration
The elastic force
of the chest wall
is exactly
balanced by the
elastic force of
the lungs
FRC = ERV + RV

IRV
IC
TV
TLC
ERV
FRC
RV

VC
RV
Volume of air in
the lungs after a
maximum
inspiration
TLC = IRV + TV +
ERV + RV
 Term
used to indicate a
battery of studies or
maneuvers that may be
performed using standardized
equipments to measure lung
function

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
Detect disease
Evaluate extent and monitor course of
disease
Evaluate treatment
Measure effects of exposures
Assess risk for surgical procedures
FEV1 IN COPD
 OCCUPATIONAL EXPOSURES

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Measurement of the pattern of air movement
into and out of the lungs during controlled
ventilatory maneuvers.
Often done as a maximal expiratory
maneuver
22
Before test

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Should not smoke within at least 4 h of testing
Should not consume alcohol within 4 h of
testing
Should not performe vigorous exercise within
30 min of testing
Should not wear strict clothes
Should not eat a large meal within 2 hours of
testing
Bronchodilator medications?
23
During test

Sitting or standing
position

Upright sitting

Nose clip
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Army chair
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Wheelchair?
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Obesity?

False teeth?
24
During test

Should be rested 5-10 min.

Should be relaxed

Should be informed on tests
25
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Dynamic studies: spirometry,
flow volume loop, PEF
Static lung volumes
Diffusing capacity
Bronchodilator test
26
No artefacts on spirogram:
 Should not cough
 Should not close glottis within 1s of
exhalation
 Should not terminate test early
 Should not perform variable effort
 Should not leak from mouthpiece
 Should not close of openness by
mouthpiece
27
BACK EXTRAPOLATION
4
ZERO TIME (EV)
VOLUME, L
3
MAXIMAL
INSPIRATORY
LEVEL
EXTRAPOLATED
VOLUME
2
1
Extrapolation volume
0
1
2
3
4
TIME, s
Ekstrapolation
A pause
volume must be < 5% of FVC or 0.150 L
of < 1s at TLC after inspirium
28
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Have patient seated comfortably
Closed-circuit technique
◦
◦
◦
◦
Place nose clip on
Have patient breathe on mouthpiece
Have patient take a deep breath as fast as possible
Blow out as hard as they can until you tell them to
stop

Forced vital capacity
(FVC):
◦ Total volume of air that
can be exhaled forcefully
from TLC
◦ The majority of FVC can
be exhaled in <3 seconds
in normal people, but
often is much more
prolonged in obstructive
diseases
◦ Measured in liters (L)

Forced expiratory
volume in 1 second:
(FEV1)
◦ Volume of air forcefully
expired from full inflation
(TLC) in the first second
◦ Measured in liters (L)
◦ Normal people can exhale
more than 75-80% of their
FVC in the first second;
thus the FEV1/FVC can be
utilized to characterize
lung disease
 80-120%
 70-79%
 51-69%
normal
mild obstruction
moderate
obstruction
 <50%
severe
obstruction

Forced expiratory flow
25-75% (FEF25-75)
◦ Mean forced expiratory
flow during middle half of
FVC
◦ Measured in L/sec
◦ May reflect effort
independent expiration
and the status of the small
airways
◦ Highly variable
◦ Depends heavily on FVC

Interpretation of % predicted:
◦
◦
◦
◦
>60%
Normal
40-60% Mild obstruction
20-40% Moderate obstruction
<10%
Severe obstruction
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Ruppel GL. Manual of Pulmonary Function Testing, 8th ed.,
Mosby 2003
Illustrates
maximum
expiratory and
inspiratory flowvolume curves
Useful to help
characterize
disease states (e.g.
obstructive vs.
restrictive)
Exhalation:
 Exhalation time must be  6s and/or a plateau
must be seen in volume time curve
 The patient cannot continue further exhalation
 No change in volume for  1 s at the end
of exhalation
 Time could be prolonged in patients with
obstruction or older subjects
36
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Volume –time display
Flow- volume display
37
38
39
Acceptable Spirogram
Volume-Time
Flow-Volume
40
Cough in 1second
Volume-Time
Flow-Volume
41
Glottic closure
Volume-Time
Flow-Volume
42
Variable effort
Early termination
Volume-Time
Flow-Volume
43
Air leak
Volume-Time
Flow-Volume
44
Spirometry Acceptability Criterias
ATS/ERS Task Force 2005
Three acceptable spirograms
The largest values of FVC must be < 0.150
L of each other
The largest values of FEV1 must be < 0.150
L
For those with an FVC of ≤ 1 L both these
values are 0.100L
If both of these criteria do not meet
Continue testing until
 Both criteria are met with acceptable
spirograms
 A total 8 tests have been performed
 The patient cannot continue
45
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Three tests with acceptable start of test and free
from artefact are selected and saved
The largest FVC and the largest FEV1 should be
recorded and FEV1 /FVC should be calculated
46
Test appropriate for the repeatability criterias
Volume-Time
Flow-Volume
47
Tekrarlanabilirlik
Kriterine
Olmayancriterias
Test
Test
not appropriate
for the Uygun
repeatability
TEKRARLANABİLİRLİK
Volume-Time
Flow-Volume
48
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Obstructive
Restrictive
Mixed
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Characterized by a
limitation of
expiratory airflow
◦ Examples: asthma,
COPD
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Decreased: FEV1,
FEF25-75, FEV1/FVC
ratio (<0.8)
Increased or
Normal: TLC
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Slow rise in
upstroke
May not reach
plateau
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Characterized by diminished
lung volume due to:
◦ change in alteration in lung
parenchyma (interstitial lung
disease)
◦ disease of pleura, chest wall
(e.g. scoliosis), or
neuromuscular apparatus
(e.g. muscular dystrophy)
Decreased TLC, FVC
Normal or increased: FEV1/FVC
ratio
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Rapid upstroke
as in normal
spirometry
Plateau volume
is low

Characterized by
a truncated
inspiratory or
expiratory loop
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