6. Spirometry should be performed after administration
of an adequate dose of a short-acting inhaled
bronchodilator to minimize variability.
A post-bronchodilator FEV1/FVC < 0.70 confirms the
presence of airflow limitation.
Where possible, values should be compared to
age-related normal values to avoid over diagnosis of
COPD in the elderly.
8. For the diagnosis and assessment of COPD,
spirometry is the gold standard.
Health care workers involved in the diagnosis
and management of COPD patients should
have access to spirometry.
10. Spirometry
“Spiro” – from the greek for breathing
“Metry” – measurement
“Spirometry” – The measurement of breathing
11. Spirometry is a measure of air flow and lung
volumes during a forced expiratory manouver
from full inspiration
Spirometry is a method of assessing lung function
by measuring the total volume of air the patient
can expel from the lungs after a maximal
inhalation.
11
What is a spirometry ??
12. Spirometric Curves
The Volume–Time Curve (The Spirogram)
The Expiratory Flow–Volume Curve
(FV Curve)
12
20. There is a lot of data reported
out on a Spirometry
The only numbers to be really concerned
with are:
– FVC
– FEV1
– FVC / FEV1 ratio
– FEF25-75%
21. Measurements
Abbreviation Characteristic measured
FEV1 Forced expired volume in 1 second
FVC Forced vital capacity
FEV1 /FVC Ratio Ratio of the above
PEFR Peak expiratory flow rate
FEF 25-75% Forced expiratory flow between 25-75% of the
vital capacity
22. 22
FEV1
FEV1 :Amount of air forcibly exhaled in the 1st
second of the FVC maneuver (80% of FVC
volume).
Volume obtained is expressed as a % of
predicted normal.
Normal 80% of predicted -Reported in liters.
23. Forced expiratory volume
in 1 second (FEV1)
A measure of FLOW
─ Reported in liters and % of predicted
─ 80 – 120% of predicted is a normal value
24. 5 10 15
2
4
6
8
Time (s)
Volume(L) Normal spirogram:
Volume / time
Man
176 cm
76 kg
FVC
FEV1
10
27. 27
Forced Vital Capacity (FVC)
Following full inspiration, patient exhales as rapidly as
possible, forcibly and completely- volume of air
exhaled is measured; takes 5-6 seconds with majority
in 1 second.
Volume obtained is expressed as a % of predicted
normal.
Normal 80% of predicted.
28. Forced vital capacity
A measure of VOLUME
– How much air that can be forcefully exhaled
– Normally FVC = VC
Varies directly with height and inversely
with age
Reported in liters and % of predicted
31. FEV1/FVC
• Forced expiratory
volume in 1 second
– 4.0 L
• Forced vital capacity
– 5.0 L
– usually less than during
a slower exhalation
• FEV1/FVC = 80%
FEV1
FVC
32. FEV1 / FVC ratio
The FEV1/FVC ratio is the ratio of the forced expiratory
volume in the first one second to the forced vital
capacity of the lungs.
The normal value for this ratio is above 75-80%,
though this is age dependent.
1. Values less than 70% are suggestive of airflow
limitation with an obstructive pattern
2. Restrictive lung diseases often produce a FEV1/FVC
ratio which is either normal or high
32
33. Forced Vital Capacity
TLC
FEV1.0
FVC
1 sec
FEV1.0 = 4 L
FVC = 5 L
% = 80%
RV
Normal
TLC
FEV1.0
FVC
1 sec
FEV1.0 = 1.2 L
FVC = 3.0 L
% = 40%
RV
Obstructive
airway resist
Restrictive
lung recoil
TLC
FEV1.0
FVC
1 sec
FEV1.0 = 2.7 L
FVC = 3.0 L
% = 90%
RV
34. Indication for lung volume test :
● Low FVC :
-? Restrictive
-? Obstructive with hyperinflation and air
trapping
-? Mixed pattern
-? Equivocal spirometry findings (FEV1&FVC at
lower limit of normal)
35. 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
36. To calculate % predicted
Actual Measurement x100
Predicted Value
– e.g. Actual FEV1 = 4.0 litres
Predicted FEV1 = 4.0 litres
4 x 100 = 100%
4
46. Obstructive Pattern
FEV1: < 80% predicted
● FVC: can be normal or reduced – usually to
a lesser degree than FEV1
FEV1/FVC: <70% predicted
47. Although the FEV1/FVC ratio is very useful in
diagnosing airflow obstruction, the absolute
value of the FEV1 is the best measure of
severity.
FEV1 used to grade the severity of air flow
limitation .
47
49. FEV1: Normal or mildly reduced –
usually to a lesser degree than FVC
FVC: < 80% predicted
FEV1/FVC: Normal or increased > 0.7
Restrictive Pattern
50. Mixed Obstructive and Restrictive
Volume,liters
Time, seconds
Restrictive and mixed obstructive-restrictive are difficult to diagnose by
spirometry alone; full pulmonary function tests are usually required
FEV1 = 0.5L
FVC = 1.5L
FEV1/FVC = 0.30
Normal
Obstructive - Restrictive
54. Bronchodilator Reversibility Testing
Preparation
●The test should be performed when patients are
clinically stable and free from respiratory infection
● Patients should not have taken:
Inhaled short-acting bronchodilators in the
previous six hours
Long-acting bronchodilator in the previous
12 hours
Sustained-release theophylline in the previous
24 hours
55. Before performing spirometry, withhold:
Short acting β2-agonists for 6 hours
Long acting β2-agonists for 12 hours
Ipratropium for 6 hours
Tiotropium for 24 hours
Sustained-release theophylline for 24 hours
Optimally, subjects should avoid caffeine and
cigarette smoking for 30 minutes before performing
spirometry
56. Bronchodilator Reversibility Testing
Bronchodilator* Dose FEV1 before
and after
Salbutamol 200 – 400 µg via large
volume spacer
15 minutes
Terbutaline 500 µg via Turbohaler® 15 minutes
Ipratropium 160 µg** via spacer 45 minutes
* Some guidelines suggest nebulised bronchodilators can be given but the
doses are not standardised. “There is no consensus on the drug, dose or
mode of administering a bronchodilator in the laboratory.” Ref: ATS/ERS
Task Force : Interpretive strategies for Lung Function Tests ERJ 2005
** Usually 8 puffs of 20 µg
57. Bronchodilator Reversibility Testing
● Possible dosage protocols:
400 µg β2-agonist, or
80-160 µg anticholinergic, or
the two combined
● FEV1 should be measured again:
15 minutes after a short-acting β2-agonist
45 minutes after the combination
60. Bronchodilator Reversibility
Testing in COPD
FEV1 should be measured (minimum twice, within
5% or 150mls) before a bronchodilator is given .
The bronchodilator should be given by metered
dose inhaler through a spacer device or by
nebulizer .
The bronchodilator dose should be selected to be
high on the dose/response curve .
62. Bronchodilator Reversibility Testing
Results
● An increase in FEV1 that is both greater than 200 ml
and 12% above the pre-bronchodilator FEV1 (baseline
value) is considered significant .
● It is usually helpful to report the absolute change (in
ml) as well as the % change from baseline to set the
improvement in a clinical context .
63. Spirometric Diagnosis of COPD
COPD is confirmed by post–bronchodilator
FEV1/FVC < 0.7
● Post-bronchodilator FEV1/FVC measured 15
minutes after e
– 4 puffs Salbutamol 100 MDI with AeroChamber
– Salbutamol 2.5mg nebuliser.
quivalent
65. – Ratios such as FEV1/VC should not be
used to judge bronchodilator
response.
66. Bronchodilator reversibility testing
Although the values that show reversibility
are arbitrary, an increase of >400 ml from
baseline in FEV1 is suggestive of asthma.
Smaller increases are less discriminatory.
(Some texts suggest 200mls.)
67. Must be interpreted with clinical history -
neither asthma nor COPD are diagnosed on
spirometry alone .
Symptoms should be present to diagnose
COPD in people with mild airflow obstruction
Helps to differentiate COPD from asthma.
Bronchodilator reversibility testing
68. Spirometry is a poor predictor of disability and
quality of life in COPD but helps in predicting
prognosis and contributes to the assessment
of the severity of COPD.
Spirometry alone cannot separate asthma from
COPD .
68
69. COPD or asthma or both?
Resolving the two conditions can be problematic,
particularly in older patients. Conditions may co-
exist (~ 20% of patients)
Clinically significant COPD is not present if FEV1
and FEV1/FVC ration return to normal with drug
treatment
Reconsider diagnosis of COPD if a patient reports
a marked response to inhaled therapies
69
70. COPD or asthma or both?
Findings that can help identify asthma (from
NICE):
1. On reversibility testing, there is a large (>400
ml) response to bronchodilators
2. A large (>400 ml) response to 2 weeks, 30
mg/day oral prednisolone
3. Serial peak flow measurements showing 20%
or greater diurnal/day-to-day variability
70
71. Reversibility testing used to be promoted in
previous international guidelines (BTS and GOLD)
to diagnose irreversible airflow limitation and
may help differentiate between other respiratory
conditions such as asthma.
However, some patients with COPD have been
shown to respond well to bronchodilators and this
method of testing can often be misleading
71
A Practical Guide to Interpreting Bronchodilator Reversibility in (COPD)
August 10, 2012
72. In the past, bronchodilator reversibility was used
diagnostically to differentiate between COPD and
asthma
Current COPD guidelines state that the degree of
bronchodilator reversibility is not recommended for
differential diagnosis with asthma and should not be
used to predict long-term response to maintenance
bronchodilator treatment .
Thus, findings from bronchodilator reversibility testing
should be interpreted with caution and in the context
of the clinical assessments
73. It is no longer recommended to differentiate
between asthma and COPD based on the
patient’s degree of bronchodilator reversibility
Current evidence suggests that most patients
with COPD do demonstrate clinically significant
bronchodilator reversibility.
73
74. The post-bronchodilator FEV1 <80% of the
predicted in combination with a FEV1/FVC ratio
of < 70% would be more sensitive and specific
to distinguish COPD from asthma than the use
of ATS and ERS BDR criteria (defined as an
increase of <12% and 200 mL of initial FEV1.)
74
75. Post-bronchodilator spirometry should be
measured to confirm the diagnosis of COPD .
The use of post-bronchilator spirometry is
used in the updated classification of COPD
75
76. Diagnosis: Spirometry
If COPD seems likely, NICE recommend
performing spirometry:
– Post-bronchodilator spirometry recommended
for COPD
e.g. 15 mins after 400 mcg salbutamol; pMDI + spacer
is suitable
– Working definition of COPD:
Airflow obstruction defined as FEV1/FVC ratio < 0.7
If FEV1 ≥ 80% predicted, a diagnosis of COPD should
only be made in the presence of respiratory symptoms
(breathlessness or cough)
76
77.
78. Peak expiratory flow rate (PEFR)
Measurement may significantly underestimate
the severity of the airflow limitation.
A normal PEFR does not exclude significant
airflow obstruction .
PEF should not be routinely used for screening,
diagnosis, or monitoring of COPD.
78
83. “At Risk” for COPD
n COPD includes four stages of severity classified by
spirometry.
n A fifth category--Stage 0: At Risk--that appeared in
the 2001 report is no longer included as a stage of
COPD, as there is incomplete evidence that the
individuals who meet the definition of “At Risk”
(chronic cough and sputum production, normal
spirometry) necessarily progress on to Stage I:
Mild COPD.
84. The public health message is that chronic
cough and sputum are not normal remains
important - their presence should trigger a
search for underlying cause(s).
84
87. 87
Spirometric Classification of COPD Severity Based on
Postbronchodilator FEV1 . GOLD Updated 2010
Arterial partial pressure of oxygen <#8.0 kPa (60 mmHg) with or without
partial pressure of CO2 > 6.7 kPa (50 mmHg) while breathing air at sea
level.
92. Case Study 1
A 53-year-old white male presents for annual visit.
Although he quit 10 years ago he is a previous
cigarette smoker with a 20 pack-year history.
During the past 12 months, he has had 3 episodes of
bronchitis.
His history of tobacco use and recent episodes of
acute bronchitis lead you to perform spirometry.
98. Results
Pre-
Bronchodilator
Post-Bronchodilator
Predicte
d
Measured % Measured % % change
FVC 4.65 4.65 100 4.95 106 6
FEV1 3.75 3.13 83 3.34 89 6
FEV1/FV
C
80 67 -13 67 -13 0
What is the severity of obstruction?
FEV1 is 83% of predicted; therefore, the obstruction is mild
Is the obstruction reversible (is reversibility present)?
FEV1 increases from 83% to 89% (6% increase) and increases
from 3,130 cc to 3,340 cc (increase of 210 cc)
Interpretation: Mild Obstruction with minimal reversibility: Mild
COPD
101. Results
Pre-Bronchodilator Post-Bronchodilator
Predicte
d
Measured % Measured % % change
FVC 3.78 1.92 51 2.7 71 34
FEV1 3.24 1.11 34 1.61 50 36
FEV1/ FVC 86 58 -28 60 -26 3
•Is the obstruction reversible (is reversibility present)?
FEV1 increases from 34% to 50% (16% increase) and increases by
500 cc
•What is the severity of restriction?
Restriction improves as the FVC changes from 51% to 71% with
bronchodilator, indicating that the “air trapping” is relieved.
Interpretation: obstruction with reversibility (Moderate obstruction)
102.
103. No Yes
Obstructive Defect
Is FVC Low? (<80% pred)
Combined Obstruction &
Restriction /or Hyperinflation
Pure Obstruction
Improved FVC with
ß-agonist
Reversible Obstruction
with ß-agonist
Further Testing with
Full PFT’s
Suspect
Asthma
Suspect
COPD
Is FEV1 / FVC Ratio Low? (<70%)
Yes
NoYes
NoYes
Diagnostic Flow Diagram for Obstruction
Adapted from Lowry.
105. Indication for lung volume test :
● Low FVC :
-? Restrictive
-? Obstructive with hyperinflation and air
trapping
-? Mixed pattern
-? Equivocal spirometry findings (FEV1&FVC at
lower limit of normal)
106. NoYes
Is FVC Low?(<80% pred)
Restrictive Defect Normal Spirometry
Further Testing with
Full PFT’s; consider
referral if moderate to
severe
Is FEV1 / FVC Ratio Low? (<70%)
No
Diagnostic Flow Diagram for Restriction
Adapted from Lowry, 1998
108. COPD – The benefits of early diagnosis,
Strategies to encourage earlier diagnosis
in primary care
109. The challenge of early detection
Pulmonary damage
Intermitent
symptoms
Breathlessness
Obstruction
110. Why does early diagnosis
matter?
1. Preserve lung function
2. Preserve quality of life for the patient
3. Encourage smoking cessation
4. Enable earlier interventions to prevent
exacerbations
5. Reduce costs
6. Decrease mortality
111. What are the barriers to earlier
diagnosis?
It is difficult to chart the progression of COPD
currently.
There are no accepted biochemical or clinical
markers to allow measurement of COPD activity.
There are however clinical predictors (of disease
progression) through increased frequency of
exacerbations
112. – Lack of interest – a heart sink disease
– Lack of facilities for diagnosis – spirometry
– Smoking or lifestyle related
Barriers for early diagnosis?
Doctor Centered
113. Barriers for early diagnosis -
Patient Related
– Low knowledge (ignorance) of the disease
– Afraid of danger diagnosis (lung cancer)
– Adaptation – getting old
– Excuse of the symptoms – smoker’s cough
114. Decline in lung function is faster in GOLD stages I
to II than III or IV
Patients with symptomatic GOLD stage I are more
likely to progress
There is no evidence that late smoking cessation
reduces decline in lung function
There is some evidence that isolated abnormal
spirometry influences smoking cessation
Is early detection of COPD a waste
of resources?
1. Enright P, White P. Detecting mild COPD: don’t waste resources. Prim Care Respir J 2011;20(1):6-8
2. Jones R. Earlier detection of COPD. Prim Care Respir J 2011;20(2):222-222.
115. Late diagnosis leads to no access to pulmonary
rehabilitation or drugs which can improve
symptoms and reduce exacerbations
Opportunistic case finding of symptomatic
disease does not involve additional resources of
screening; certainly in many countries this is part
of the core services that primary care should
provide.
Is early detection of COPD a waste
of resources?
1. Enright P, White P. Detecting mild COPD: don’t waste resources. Prim Care Respir J 2011;20(1):6-8
2. Jones R. Earlier detection of COPD. Prim Care Respir J 2011;20(2):222-222.
117. Should general practitioners screen
smokers for COPD?
Screening for pre-clinical COPD in general
practice should not be recommended.
However, it is important to diagnose people
who may benefit from symptom-relieving
treatment, and therefore patients with
smoking-related symptoms should be
offered spirometry.
11
7
119. Finally, the general practitioner should strive
to offer smoking cessation counseling to all
smokers, regardless of their lung function.
11
9
120. And who to screen?
With active screening you find lot of smokers with
COPD, earlier unrecognised COPD
27% of the smokers,
40-55 years, had COPD
85% of those had mild
COPD
Mild COPD
Moderate COPD
Severe
COPD
Stratelis G et al. Br J Gen Pract 2004; 54:201-6
121. Spirometry should be performed in all
patients suspected of having COPD
In the absence of availability of spirometry,
patients suspected of having COPD should
be referred for spirometric evaluation to a
center with the facility.
124. COPD is a slowly progressing disease which is
often unrecognised until it is clinically apparent
and moderately advanced.
What to look for: Fatigue, dyspnoea, “smokers
cough”, chronic cough, sputum production,
wheezing
- people do not see the doctor for this
We need a Spirometer to confirm the diagnosis
and assess severity
Conclusions
125. The public health message is that chronic cough
and sputum are not normal - their presence
should trigger a search for underlying cause(s).
Early intervention will help to preserve lung
function which in turn will reduce the risk of COPD
exacerbations
Earlier diagnosis would enable healthcare
workers to encourage smoking cessation.
12
5
Conclusions
126. If you test one smoker
with cough every day
You will diagnose
one patient
With COPD
a week
