2. GIỚI THIỆU
Hô hấp ký là một trong bốn xét nghiệm
cơ bản của thăm dò CNHH (hô hấp ký,
đo tổng dung lượng phổi, khả năng
khuếch tán của phổi và khí trong máu).
Là tiêu chuẩn vàng để chẩn đoán COPD
Là dụng cụ dùng để đo các thể tích hít
vào và thở ra theo thời gian.
Giá trị lâm sàng của HHK phụ thuộc vào
chất lượng máy, kỹ thuật đo, và chọn
giá trị dự đoán phù hợp.
3. CÁC LOẠI HÔ HẤP KÝ
Máy đo thể tích theo thời gian:
Là loại cổ điển có chuông úp trên một
thùng nước hay dạng đèn xếp.
9. Các thể tích và dung tích phổi
4 thể tích: thể tích
dự trữ hít vào, thể
tích khí lưu thông,
thể tích dự trữ thở
ra, và thể tích khí
cặn
4 dung tích: dung
tích sống, dung tích
hít vào, dung tích
cặn chức năng,
dung tích phổi toàn
bộ
10. Các thể tích phổi
Thể tích khí lưu thông
(Tidal Volume- TV):
Thể tích khí của một
lần hít vào hoặc thở ra
bình thường
Thể tích dự trữ hít vào
(Inspiratory Reserve
Volume -IRV): Thể tích
khí hít vào thêm khi
gắng sức, sau khi đã
hít vào bình thường
Thể tích khí dự trữ thở
ra (Expiratory Reserve
Volume -ERV): Thể tích
khí thở ra thêm được
khi gắng sức, sau khi
đã thở ra bình thường
11. Các thể tích phổi
Thể tích khí cặn
(Residual Volume
-RV):
Thể tích khí vẫn còn
ở trong phổi sau khi
thở ra tối đa
Được đo trực tiếp
(FRC-ERV) bằng
phế thân kế (Body
Plethysmography)
hay pha loãng
helium, không đo
bằng spirometry
12. Các dung tích phổi
Total Lung Capacity
(TLC): Tổng các thể
tích trong phổi
Vital Capacity (VC):
Thể tích lớn nhất mà
người ta có thể huy
động được bằng cách
thở ra hết sức sau khi
đã hít vào hết sức
Inspiratory Capacity
(IC): Tổng của thể tích
dự trữ hít vào và thể
tích khí lưu thông
13. Các dung tích phổi (tt)
Dung tích cặn chức
năng (Functional
Residual Capacity -
FRC):
Tổng RV và ERV
hoặc thể tích khí của
phổi ở cuối thì thở ra
bình thường
Được đo bằng phế
thân kế (Body
Plethysmography)
hay pha loãng
helium, không đo
bằng spirometry
14. CÁC CHỈ SỐ HÔ HẤP KÝ
FVC (Forced vital capacity):
Thể tích khí toàn bộ được thở ra gắng sức
trong một lần thở
FEV1 (Forced expiratory volume in one
second): Thể tích khí thở ra trong giây đầu
Tỉ số FEV1/FVC (chỉ số Gaensler); FEV1/VC (
chỉ số Tiffeneau):
Phân số khí được thở ra trong giây đầu liên
quan với thể tích khí toàn bộ được thở ra
15. CÁC CHỈ SỐ HÔ HẤP KÝ
FEF 25-75% (Forced Expiratory
Flow between 25% and 75% of the
FVC)(L/s):
Lưu lượng thở ra gắng sức trong
khoảng 25 – 75% của dung tích
sống gắng sức
PEF ( Peak Expiratory Flow)(L/s):
Lưu lượng thở ra đỉnh
16. CÁC CHỈ SỐ HÔ HẤP KÝ (tt)
PIF ( Peak Inspiratory Flow)(L/s):
Lưu lượng hít vào đỉnh: Lưu lượng cao nhất
trong lúc hít vào, thường được dùng để đánh
giá tắc nghẽn đường hô hấp trên.
MVV ( Maximal Volumtary Ventilation)
(L/phút)
Thể tích thông khí tự ý tối đa
21. CÁC GIÁ TRỊ BÌNH THƯỜNG
ĐƯỢC DỰ ĐOÁN
Phụ thuộc vào:
Tuổi
Chiều cao
Giới
Chủng tộc
22. CÁC GIÁ TRỊ BÌNH THƯỜNG
ĐƯỢC DỰ ĐOÁN (tt)
Được dựa trên các khảo sát trong dân số
lớn
Các giá trị được dự đoán là các giá trị
trung bình lấy từ kết quả khảo sát
Không có các khảo sát trong dân số
người già
23. Tiêu chuẩn cho một hô hấp ký bình
thường sau dãn phế quản
FEV1: % dự đoán > 80%
FVC: % dự đoán > 80%
FEV1/FVC: > 0.7
24. Đường cong lưu lượng - thể tích
và thể tích theo thời gian của một người bình thường
34. ĐƯỜNG CONG LƯU LƯỢNG -THỂ
TÍCH
chuẩn cho hầu hết các máy hô hấp ký
để bàn
Cung cấp thông tin thêm vào đường
cong thể tích theo thời gian
Không quá khó để giải thích kết quả
Phát hiện tốt hơn khi có sự tắc nghẽn
luồng khí nhẹ
36. CHỈ ĐỊNH
Đánh giá các triệu chứng, các dấu hiệu bệnh
phổi
Đánh giá sự tiến triển của bệnh phổi
Theo dõi hiệu quả điều trị
Đánh giá nguy cơ hô hấp trước phẫu thuật
Giám định y khoa về sức khỏe hô hấp
Tầm soát các đối tượng có nguy cơ bệnh phổi
Theo dõi tác dụng độc hại của một số thuốc,
hóa chất
37. CHỐNG CHỈ ĐỊNH
Tình trạng tim mạch không ổn định
Nhồi máu cơ tim gần đây
Phẫu thuật mắt, ngực, bụng gần đây
Tràn khí màng phổi
Phình động mạch chủ
Ho ra máu
Các tình trạng cấp tính như chóng mặt,
viêm phổi
38. CÁC BIẾN CHỨNG
Ngất, chóng mặt, nhức đầu nhẹ
Co thắt phế quản
Ho
Giảm độ bão hòa oxy nếu điều trị
oxy bị gián đoạn
Áp lực nội sọ tăng
Tràn khí màng phổi
Đau ngực
Nhiễm trùng
41. SPIROMETRY AND RELATED TESTS
Learning Objectives
Determine whether spirometry is
acceptable and reproducible
Identify airway obstruction using forced
vital capacity (FVC) and forced expiratory
volume (FEV1)
Differentiate between obstruction and
restriction as causes of reduced vital
capacity
42. SPIROMETRY AND RELATED TESTS
Learning Objectives
Distinguish between large and small
airway obstruction by evaluating flow-volume
curves
Determine whether there is a significant
response to bronchodilators
Select the appropriate FVC and FEV1 for
reporting from series of spirometry
maneuvers
43. Predicted Values
Laboratory Normal Ranges
Laboratory tests performed on a large
number of normal population will show
a range of results
45. Predicted Values
Laboratory Normal Ranges
Most clinical laboratories consider
two standard deviations from the
mean as the normal range since it
includes 95% of the normal
population.
46. PFT Reports
o When performing PFT’s three values
are reported:
o Actual – what the patient performed
o Predicted – what the patient should
have performed based on Age, Height,
Sex, Weight, and Ethnicity
o % Predicted – a comparison of the
actual value to the predicted value
47. PFT Reports
Example
Actual Predicted %Predicted
VC 4.0 5.0 80%
48. SPIROMETRY
Vital Capacity
The vital capacity (VC) is the volume
of gas measured from a slow,
complete expiration after a maximal
inspiration, without a forced effort.
50. SPIROMETRY
Vital Capacity
Valid VC measurements important
IC and ERV used to calculate
RV and TLC
Example:
RV = FRC - ERV
TLC = IC + FRC
51. SPIROMETRY
VC: Criteria for Acceptability
1. End-expiratory volume varies by less than
100 ml for three preceding breaths
2. Volume plateau observed at maximal
inspiration and expiration
52. SPIROMETRY
VC: Criteria for Acceptability
3. Three acceptable VC maneuvers should be
obtained; volume within 150 ml.
4. VC should be within 150 ml of FVC value
53. SPIROMETRY
VC: Selection Criteria
The largest value from at least 3 acceptable
maneuvers should be reported
54. SPIROMETRY
VC: Significance/Pathophysiology
Decreased VC
Loss of distensible lung tissue
Lung CA
Pulmonary edema
Pneumonia
Pulmonary vascular congestion
Surgical removal of lung tissue
Tissue loss
Space-occupying lesions
Changes in lung tissue
56. SPIROMETRY
VC: Significance/Pathophysiology
Decreased VC
Limited movement of diaphragm
Pregnancy
Abdominal fluids
Tumors
Limitation of chest wall movement
Scleraderma
Kyphoscoliosis
Pain
57. SPIROMETRY
VC: Significance/Pathophysiology
If the VC is less than 80% of
predicted: FVC can reveal if caused by
obstruction
58. SPIROMETRY
VC: Significance/Pathophysiology
If the VC is less than 80% of
predicted: Lung volume testing can
reveal if caused by restriction
59. SPIROMETRY
Forced Vital Capacity (FVC)
The maximum volume of gas that
can be expired when the patient
exhales as forcefully and rapidly as
possible after maximal inspiration
(sitting or standing)
61. SPIROMETRY
FVC: Criteria for Acceptability
1. Maximal effort; no cough or glottic closure
during the first second; no leaks or obstruction
of the mouthpiece.
2. Good start-of-test; back extrapolated volume
<5% of FVC or 150 ml, whichever is greater
62. SPIROMETRY
FVC: Criteria for Acceptability
3. Tracing shows 6 seconds of exhalation or an
obvious plateau (<0.025L for ≥1s); no early
termination or cutoff; or subject cannot or
should not continue to exhale
63. SPIROMETRY
FVC: Criteria for Acceptability
4. Three acceptable spirograms obtained; two
largest FVC values within 150 ml; two largest
FEV1 values within 150 ml
64. SPIROMETRY
FVC: Selection Criteria
The largest FVC and largest FEV1 (BTPS)
should be reported, even if they do not
come from the same curve
65. SPIROMETRY
FVC: When to call it quits !!!
If reproducible values cannot be
obtained after eight attempts, testing
may be discontinued
66. SPIROMETRY
FVC: Significance and Pathophysiology
FVC equals VC in healthy individuals
FVC is often lower in patients with
obstructive disease
67. SPIROMETRY
FVC: Significance and Pathophysiology
FVC can be reduced by:
Mucus plugging
Bronchiolar narrowing
Chronic or acute asthma
Bronchiectasis
Cystic fibrosis
Trachea or mainstem bronchi obstruction
68. SPIROMETRY
FVC: Significance and Pathophysiology
Healthy adults can exhale their FVC
within 4 – 6 seconds
Patients with severe obstruction (e.g.,
emphysema) may require 20 seconds,
however, exhalation times >15
seconds will rarely change clinical
decisions
69. SPIROMETRY
FVC: Significance and Pathophysiology
FVC is also decreased in restrictive
lung disease
Pulmonary fibrosis
dusts/toxins/drugs/radiation
Congestion of pulmonary blood flow
pneumonia/pulmonary hypertension/PE
Space occupying lesions
tumors/pleural effusion
70. SPIROMETRY
FVC: Significance and Pathophysiology
FVC is also decreased in restrictive
lung disease
Neuromuscular disorders, e.g,
myasthenia gravis, Guillain-Barre
Chest deformities, e.g,
scoliosis/kyphoscoliosis
Obesity or pregnancy
71. SPIROMETRY
Forced Expiratory Volume (FEV1)
The volume expired over the first
second of an FVC maneuver
72. SPIROMETRY
Forced Expiratory Volume (FEV1)
May be reduced in obstructive or
restrictive patterns, or poor patient
effort
73. SPIROMETRY
Forced Expiratory Volume (FEV1)
In obstructive disease, FEV1 may be
decreased because of:
Airway narrowing during forced expiration
emphysema
Mucus secretions
Bronchospasm
Inflammation (asthma/bronchitis)
Large airway obstruction
tumors/foreign bodies
74. SPIROMETRY
Forced Expiratory Volume (FEV1)
The ability to work or function in daily
life is related to the FEV1 and FVC
Patients with markedly reduced FEV1
values are more likely to die from COPD or
lung cancer
76. SPIROMETRY
Forced Expiratory Volume (FEV1)
FEV1 is the most widely used
spirometric parameter, particularly
for assessment of airway
obstruction
77. SPIROMETRY
Forced Expiratory Volume (FEV1)
FEV1 is used in conjunction with
FVC for:
Simple screening
Response to bronchodilator therapy
Response to bronchoprovocation
Detection of exercise-induced
bronchospasm
78. SPIROMETRY
Forced Expiratory Volume Ratio (FEVT%)
FEVT% = FEVT/FVC x 100
Useful in distinguishing between
obstructive and restrictive causes of
reduced FEV1 values
79. SPIROMETRY
Forced Expiratory Volume Ratio (FEVT%)
Normal FEVT% Ratios for Health Adults
FEV 0.5% = 50%-60%
FEV 1% = 75%-85%
FEV 2% = 90%-95%
FEV 3% = 95%-98%
FEV 6% = 98%-100%
Patients with obstructive disease have
reduced FEVT% for each interval
80. SPIROMETRY
Forced Expiratory Volume Ratio (FEVT%)
A decrease FEV1/FVC ratio is the
“hallmark” of obstructive disease
FEV1/FVC <75%
81. SPIROMETRY
Forced Expiratory Volume Ratio (FEVT%)
Patients with restrictive disease often have
normal or increased FEVT% values
FEV1 and FVC are usually reduced in equal
proportions
The presence of a restrictive disorder may
by suggested by a reduced FVC and a
normal or increased FEV1/FVC ration
82. SPIROMETRY
Forced Expiratory Flow 25% - 75%
(maximum mid-expiratory flow)
FEF 25%-75% is measured from a
segment of the FVC that includes flow
from medium and small airways
Normal values: 4 – 5 L/sec
83. SPIROMETRY
Forced Expiratory Flow 25% - 75%
In the presence of a borderline
value for FEV1/FVC, a low FEF
25%-75% may help confirm
airway obstruction
84. SPIROMETRY
Flow – Volume Curve
AKA: Flow–Volume Loop (FVL)
The maximum expiratory flow-volume
(MEFV) curve shows flow
as the patient exhales from
maximal inspiration (TLC) to
maximal expiration (RV)
FVC followed by FIVC
85. SPIROMETRY
FVL
X axis: Volume
Y axis: Flow
PEF (Peak Expiratory Flow)
PIF (Peak Inspiratory Flow)
.
Vmax 75 or FEF 25%
FVC Remaining or Percentage FVC exhaled
.
Vmax 50 or FEF 50%
.
Vmax 25 or FEF 75%
FEF 25% or Vmax 75
FEF 75% or Vmax 25%
86. SPIROMETRY
FVL
FEVT and FEF% can be read from
the timing marks (ticks) on the FVL
87. SPIROMETRY
FVL
Significant decreases in flow or volume
are easily detected from a single graphic
display
90. SPIROMETRY
Peak Expiratory Flow (PEF)
The maximum flow obtained
during a FVC maneuver
Measured from a FVL
In laboratory, must perform a
minimum of 3 PEF maneuvers
Largest 2 of 3 must be within 0.67
L/S (40 L/min)
Primarily measures large airway
function
Many portable devices available
91. SPIROMETRY
Peak Expiratory Flow (PEF)
When used to monitor asthmatics
Establish best PEF over a 2-3 week
period
Should be measured twice daily
(morning and evening)
Daily measurements are compared to
personal best
92. SPIROMETRY
Peak Expiratory Flow (PEF)
The National Asthma Education Program
suggests a zone system
Green: 80%-100% of personal best
Routine treatment can be continued; consider
reducing medications
Yellow: 50%-80% of personal best
Acute exacerbation may be present
Temporary increase in medication may be
needed
Maintenance therapy may need increases
Red: Less than 50% of personal best
Bronchodilators should be taken immediately;
begin oral steroids; clinician should be
notified if PEF fails to return to yellow or
green within 2 – 4 hours
93. SPIROMETRY
Peak Expiratory Flow (PEF)
PEF is a recognized means of
monitoring asthma
Provides serial measurements
of PEF as a guide to treatment
ATS Recommended Ranges
60-400 L/min (children)
100-850 L/min (adults)
94. SPIROMETRY
Maximum Voluntary Ventilation
(MVV)
The volume of air exhaled in a
specific interval during rapid, forced
breathing
95. SPIROMETRY
MVV
Rapid, deep breathing
VT ~50% of VC
For 12-15 seconds
96. SPIROMETRY
MVV
Tests overall function of
respiratory system
Airway resistance
Respiratory muscles
Compliance of lungs/chest wall
Ventilatory control mechanisms
97. SPIROMETRY
MVV
At least 2 acceptable maneuvers should be
performed
Two largest should be within 10% of each
other
Volumes extrapolated out to 60 seconds
and corrected to BTPS
MVV is approximately equal to 35 time the
FEV1
98. SPIROMETRY
MVV
Selection Criteria
The highest MVV (L/min, BTPS) and MVV
rate (breaths / min) should be reported
99. SPIROMETRY
MVV
Decreased in:
Patients with moderate to severe
obstructive lung disease
Patients who are weak or have decreased
endurance
Patients with neurological deficits
100. SPIROMETRY
MVV
Decreased in:
Patients with paralysis or nerve damage
A markedly reduced MVV correlates with
postoperative risk for patients having
abdominal or thoracic surgery
101. SPIROMETRY
Before/After Bronchodilator
Spirometry is performed before
and after bronchodilator
administration to determine the
reversibility of airway obstruction
102. SPIROMETRY
Before/After Bronchodilator
An FEV1% less than predicted is a
good indication for bronchodilator
study
In most patients, an FEV1% less
than 70% indicates obstruction
103. SPIROMETRY
Before/After Bronchodilator
Any pulmonary function parameter
may be measured before and after
bronchodilator therapy
FEV1 and specific airway
conductance (SGaw) are usually
evaluated
104. SPIROMETRY
Before/After Bronchodilator
Lung volumes should be recorded
before bronchodilator
administration
Lung volumes and DLco may also
respond to bronchodilator therapy
106. SPIROMETRY
Before/After Bronchodilator
Minimum of 10 minutes, up to 15
minutes, between administration
and repeat testing is recommended
(30 minutes for short-acting
anticholinergic agents)
FEV1, FVC, FEF25%-75%, PEF,
SGaw are commonly made before
and after bronchodilator
administration
107. SPIROMETRY
Before/After Bronchodilator
Percentage of change is calculated
%Change = Postdrug – Predrug X 100
Predrug
108. SPIROMETRY
Before/After Bronchodilator
FEV1 is the most commonly used
test for quantifying bronchodilator
response
FEV1% should not be used to judge
bronchodilation response
SGaw may show a marked increase
after bronchodilator therapy
109. SPIROMETRY
Before/After Bronchodilator
Significance and Pathophysiology
Considered significant if:
FEV1 or FVC increase ≥12% and ≥200 ml
SGaw increases 30% - 40%
110. SPIROMETRY
Before/After Bronchodilator
Significance and Pathophysiology
Diseases involving the bronchial
(and bronchiolar) smooth muscle
usually improve most from “before”
to “after”
Increase >50% in FEV1 may occur in
patients with asthma
111. SPIROMETRY
Before/After Bronchodilator
Significance and Pathophysiology
Patients with chronic obstructive
diseases may show little
improvement in flows
Inadequate drug deposition (poor
inspiratory effort)
Patient may respond to different drug
Paradoxical response <8% or 150 ml not
significant
112. SPIROMETRY
Maximal Inspiratory Pressure
(MIP)
The lowest pressure developed
during a forceful inspiration against
an occluded airway
Primarily measures inspiratory muscle
strength
113. SPIROMETRY
MIP
Usually measured at maximal
expiration (residual volume)
Can be measured at FRC
Recorded as a negative number in
cm H20 or mm Hg, e.g. (-60 cm H2O)
115. SPIROMETRY
MIP
Significance and Pathophysiology
Healthy adults > -60 cm H2O
Decreased in patients with:
Neuromuscular disease
Diseases involving the diaphragm,
intercostal, or accessory muscles
Hyperinflation (emphysema)
116. SPIROMETRY
MIP
Significance and Pathophysiology
Sometimes used to measure
response to respiratory muscle
training
Often used in the assessment of
respiratory muscle function in
patients who need ventilatory
support
117. SPIROMETRY
Maximal Expiratory Pressure (MEP)
The highest pressure developed
during a forceful exhalation against
an occluded airway
Dependent upon function of the
abdominal muscles, accessory muscles
of expiration, and elastic recoil of lung
and thorax
118. SPIROMETRY
MEP
Usually measured at maximal
inspiration (total lung capacity)
Can be measured at FRC
Recorded as a positive number in
cm H20 or mm Hg
120. SPIROMETRY
MEP
Significance and Pathophysiology
Healthy adults >80 to 100 cm H2O
Decreased in:
Neuromuscular disorders
High cervical spine fractures
Damage to nerves controlling
abdominal and accessory muscles of
inspiration
121. SPIROMETRY
MEP
Significance and Pathophysiology
A low MEP is associated with
inability to cough
May complicate chronic bronchitis, cystic
fibrosis, and other diseases that result in
excessive mucus production
122. SPIROMETRY
Airway Resistance (Raw)
The drive pressure required to
create a flow of air through a
subject’s airway
Recorded in cm H2O/L/sec
When related to lung volume at the
time of measurement it is known as
specific airway resistance (SRaw)
123. SPIROMETRY
Raw
Measured in a
plethysmograph
as the patient
breathes
through a
pneumo-tachometer
124. SPIROMETRY
Raw
Criteria of Acceptability
Mean of three or more acceptable
efforts should be reported;
individual values should be within
10% of mean
125. SPIROMETRY
Airway Resistance (Raw)
Normal Adult Values
Raw 0.6 – 2.4 cm H2O/L/sec
SRaw 0.190 – 0.667 cm H2O/L/sec/L
127. SPIROMETRY
Raw
Significance and Pathology
Increased in acute asthmatic episodes
Increased in advanced emphysema because of
airway narrowing and collapse
Other obstructive disease, e.g., bronchitis may
cause increase in Raw proportionate to the
degree of obstruction in medium and small
airways
128. SPIROMETRY
Airway Conductance (Gaw)
A measure of flow that is generated
from the available drive pressure
Recorded in L/sec/cm H2O
Gaw is the inverse of Raw
When related to lung volume at the
time of measurement it is known as
specific airway conductance (SGaw)
129. SPIROMETRY
Gaw
Measured in a
plethysmograph
as the patient
breathes
through a
pneumo-tachometer
130. SPIROMETRY
Gaw
Criteria of Acceptability
Mean of three or more acceptable
efforts should be reported;
individual values should be within
10% of mean
132. SPIROMETRY
Airway Conductance (Gaw)
Significance and Pathology
SGaw Values <0.15 – 0.20
L/sec/cm H2O/L are consistent
with airway obstruction
133. Quiz Practice
Most clinical laboratories consider
two standard deviations from the
mean as the normal range when
determining predicted values since it
includes 95% of the normal
population.
a. False
b. Only for those individuals with lung
disease
c. This applies only to cigarette smokers
d. True
134. Quiz Practice
Vital capacity is defined as which of
the following?
a. The volume of gas measured from a slow,
complete exhalation after a maximal
inspiration, without a forced effort
b. The volume of gas measured from a rapid,
complete exhalation after a rapid maximal
inspiration
c. The volume of gas measured after 3 seconds of
a slow, complete exhalation
d. The total volume of gas within the lungs after a
maximal inhalation
135. Quiz Practice
Which of the following statements are
true regarding the acceptability criteria
for vital capacity measurement?
I. End-expiratory volume varies by less than 100
ml for three preceding breaths
II. Volume plateau observed at maximal inspiration
and expiration
III. Three acceptable vital capacity maneuvers
should be obtained; volume within 150 ml
IV. Vital capacity should be within 150 ml of forced
vital capacity in healthy individuals
a. I, II, and IV
b. II, III, and IV
c. III and IV
d. I, II, III, IV
136. Quiz Practice
Which of the following best
describes the Forced Vital Capacity
(FVC) maneuver?
a. The volume of gas measured from a slow,
complete exhalation after a maximal
inspiration, without a forced effort
b. The volume of gas measured from a slow,
complete exhalation after a rapid maximal
inspiration
c. The volume of gas measured after 3 seconds
of a rapid, complete exhalation
d. The maximum volume of gas that can be
expired when the patient exhales as forcefully
and rapidly as possible after maximal
inspiration
137. Quiz Practice
All of the following are true
regarding the acceptability
criteria of an FVC maneuver
EXCEPT?
a. Maximal effort, no cough or glottic
closure during the first second; no leaks
of obstruction of the mouthpiece
b. Good start of test; back extrapolated
volume less than 5% of the FVC or 150 ml
c. Tracing shows a minimum of 3 seconds of
exhalation
d. Three acceptable spirograms obtained;
two largest FVC values within 150 ml; two
largest FEV1 values within 150 ml
138. Quiz Practice
The FEV1 is the expired volume of
the first second of the FVC
maneuver.
a. True
b. False
c. Only when done slowly
d. Only when divided by the FVC
139. Quiz Practice
Which of following statements is
true regarding FEV1?
a. FEV1 may be larger than the FVC
b. FEV1 is always 75% of FVC
c. May be reduced in obstructive and
restrictive lung disease
d. Is only reduced in restrictive disease
140. Quiz Practice
The FEV1% is useful in
distinguishing between obstructive
and restrictive causes of reduced
FEV1 values
a. True
b. False
c. Only helps to distinguish obstructive
lung disease
d. Only helps to distinguish restrictive
lung disease
141. Quiz Practice
Which statements are true
regarding the FEV 1%, also known
as the FEV1/FVC?
I. A decreased FEV1/FVC is the hallmark of
obstructive disease
II. Patients with restrictive lung disease often
have normal or increased FEV1/FVC ratios
III. The presence of a restrictive disorder may
be suggested by a reduced FVC and a
normal or increased FEV1/FVC ratio
IV. A normal FEV1/FVC ratio is between 75%
- 85%
a. I and II
b. I, II and III
c. II, III and IV
d. I, II, III and IV
142. Quiz Practice
What test is
represented by the
graph to the right?
a. Forced Vital Capacity
b. Flow-Volume Loop
c. Slow Vital Capacity
d. Total Lung Capacity
Maneuver
143. Quiz Practice
What type of pulmonary disorder is
represented by the graph below?
a. Obstructive lung disease
b. Restrictive lung disease
c. Upper airway obstruction
d. Normal lung function
(The dotted lines represent the predicted values)
144. Quiz Practice
Which is true regarding Peak
Expiratory Flow (PEF)?
I. Primarily measures large airway function
II. Is a recognized means of monitoring
asthma
III. Serial measurements of PEF are used a
guide to treat asthma
IV. When less than 50% of personal best, it is
an indication that immediate treatment is
required
a. I only
b. II and III
c. II, III, and IV
d. I, II, III, and IV
145. Quiz Practice
MVV is decreased in patients with
which of the following disorders?
I. Moderate to severe obstructive lung
disease
II. Weak or with decrease endurance
III. Neurological defects
IV. Paralysis or nerve damage
a. I and IV
b. II and III
c. III and IV
d. I, II, III, and IV
146. Quiz Practice
Spirometry before and after
bronchodilator therapy is used to
determine which of the following?
a. Reversibility of airway obstruction
b. The severity of restrictive disorders
c. The rate at which CO diffuses through the lung
into the blood
d. If the patient has exercised induced asthma
147. Quiz Practice
What is the minimum amount of
time between administration of
bronchodilator therapy and repeat
pulmonary function testing?
a. 5 minutes
b. 10 minutes
c. 30 minutes
d. 60 minute
148. Quiz Practice
Bronchodilation is considered
significant when which of the
following occurs?
a. FEV1/FVC increases by 12%
b. SGaw increases by 12%
c. FVC and/or FEV1 increases by 12% and 150 ml
d. DLco increases by 12%
149. Quiz Practice
Which of the following is true
regarding Maximal Inspiratory
Pressure (MIP)?
I. Primarily measures inspiratory muscle
strength
II. Measures airway resistance during
inspiration
III. Is decreased in patients with neurological
disease
IV. Often used in the assessment of
respiratory muscle function in patients
who need ventilatory support
a. I, II, and III
b. I, III, and IV
c. II and III
d. II, III, and IV
150. Quiz Practice
Airway resistance (Raw) is the
drive pressure required to create a
flow of air through a subject’s
airway.
a. True
b. False
c. Only in patients with COPD
d. Only in patients with restrictive
disorders
151. Quiz Practice
Airway resistance may be increased
in which of the following patients?
I. Purely restrictive lung disorders
II. Acute asthmatic episodes
III. Mucus secretion
IV. Lung compliance changes
a. I only
b. I and IV
c. II and III
d. I, II, III, and IV
152. Quiz Practice
Airway Conductance (Gaw) is a
measure of flow that is generated
from the available drive pressure.
a. True
b. False
c. Only in patients with COPD
d. Only in patients with restrictive
disorders
153. Quiz Practice
A patient’s pulmonary function
tests reveal the following:
Actual Predicted %Predicted
FVC 4.01 L 4.97 L 81
FEV1 2.58 L 3.67 L 56
FEV1% 51 >75 _
Select the correct interpretation
a. Restrictive pattern
b. Obstructive pattern
c. Inconclusive
d. Normal
154. Quiz Practice
A patient’s pulmonary function tests reveal
the following:
Actual Predicted %Predicted
FVC 3.75 L 4.97 L 75
FEV1 2.80 L 3.67 L 76
FEV1% 75 >/=75 _
Select the correct interpretation
a. Restrictive pattern
b. Obstructive pattern
c. Inconclusive
d. Normal