A technique used to measure air flow in and out of the lungs.
A recording of lung volumes and capacities defined by the respiratory process. These recordings may be static (untimed) or dynamic (timed).
Assesses the integrated mechanical functions of lungs, chest wall and respiratory muscles.
The gold standard for diagnosis, assessment and monitoring of COPD.
Better than PEFR (which is effort dependent) for demonstrating airway obstruction in BA.
The most commonly used PFT
2. What is Spirometry?
a simple and safe test
that measures lung volumes
with a graphical display
gives an estimation of lung function
Allows for diagnosis of
airflow obstruction
Permits good follow-up
for asthma and COPD
3. Spirometry
in Practice
• A technique used to measure air flow in and out of
the lungs.
• A recording of lung volumes and capacities defined
by the respiratory process. These recordings may be
static (untimed) or dynamic (timed).
• Assesses the integrated mechanical functions of
lungs, chest wall and respiratory muscles.
•The gold standard for diagnosis, assessment and
monitoring of COPD.
• Better than PEFR (which is effort dependent) for
demonstrating airway obstruction in BA.
• The most commonly used PFT.
4. Indications
• Measure airflow obstruction to help make a
definitive diagnosis of COPD
• Detect airflow obstruction in smokers who may
have few or no symptoms
• Assess one aspect of response to therapy
• Perform pre-operative assessment
• Distinguish between obstruction and restriction
as causes of breathlessness
• Perform pre-employment screening in certain
professions
17. 5 10 15
2
4
6
8
Time (s)
Volume(L)
Normal spirogram:
Volume / time
Man
176 cm
76 kg
FVC
FEV1
18. Two important
parameters
FVC - Forced Vital Capacity. This is the
total amount of air that you blow out
in one breath.
FEV1 - Forced Expiratory Volume in
one Second. This is the amount of air
you can blow out within one second.
With normal lungs and airways you
can normally blow out most of the air
from your lungs within one second.
24. Spirometry and ageing
0 1 2 3 4 5 6
0
2
4
6
8
10
Vol (l)
Flow(l/s)
25 yrs
175 cm
male
75 yrs
171 cm
male
25. Spirometry allows for
Early detection of airflow obstruction
(often late signs and symptoms)
Better diagnosis (helps to distinguish
between asthma and COPD)
Correct follow-up (compare with blood
pressure meter in hypertension patients)
26. Reversibility Testing
If airflow obstruction is present, the
test person is given a bronchodilator
(inhalation device)