4. PFT
• Volumes – measured value
• Capacities - sum of 2 or
more lung volumes
Inspiratory
Reserve
Volume
Normal values:
FVC > 80% predicted
FEV1> 80% predicted
FEV1/FVC > 70
5. • Forced vital capacity (FVC):
– Total volume of air that can be exhaled
forcefully after maximum inhalation
– Interpreted as % predicted
• Forced expiratory volume in 1
second: (FEV1)
– Volume of air forcefully expired from full
inflation (TLC) in the first second
– > 80 % Normal
– 70-79% Mild reduction
– 50%-69% Moderate reduction
– <49% Severe reduction
– <30% Very severe reduction
13. Diffusion Capacity
Diffusing capacity of lungs for CO
Measures ability of lungs to transport inhaled gas
from alveoli to pulmonary capillaries
Depends on:
- alveolar—capillary membrane
- hemoglobin concentration
- cardiac output
16. FVC FEV1 FEV1/FVC TLC DLCO
Obstruction
Nor
Asthma N or
COPD
Restriction N or
ILD
Extra-
Parenchymal
Mixed
Interpretation
N
17. • Instant start of exhalation
• Rapid rise in flow to peak flow
• Sharp peak occurring
early in exhalation
• Smooth continuous fall in flow
without interruption
• Slow fall to RV
• Smooth continuous inhalation to
TLC
• Reproducible(5% OR 0.2L)
• Slow start
• Slow rise to peak flow
• Slow late peak
• Coarse flow with interruptions
• Abrupt end to RV
• Incomplete inhalation
• Non reproducible
Acceptable Not acceptable
31. A 15 years old student presented with recurrent cough and
shortness of breath.
A pulmonary function test is done.
Measured
(L)
% age
predicted
Post-
broncho-
dilator (L)
%age
change
FVC 3.50 100 3.70
FEV1 2.30 75 2.70 17
FEV1/F
VC
65
What is the most likely diagnosis?
Significant Reversibility
>12% and >200ml
Bronchial Asthma
32. A 57 yrs old man with 30 pack yrs of smoking presented with
progressive dyspnea for one year.
PFT is shown:
measured % age
predicted
post %age
change
FVC 3.05 88 3.11
FEV1 1.36 45 1.47 9
FEV1/FVC 52
TLC 4.99 97
DLCO 2.46 27
What is the most likely cause of this patient’s dyspnea?
COPD
33. What is the most likely Diagnosis?
A. Bronchial Asthma
B. COPD
C. Interstitial Lung Disease
D. Obesity Hypoventilation Syndrome
measured % age predicted
FVC 1.40 39
FEV1 1.75 55
FEV1/FVC 96
TLC 3.11 58
DLCO 7.44 87
• A 45 yrs old female with a BMI of 32 presented with
chronic hypercapnic respiratory failure.
• PFT is shown.
34. • A 20 yrs old female presents with progressive dyspnea for one
year. PFT result is shown:
measured % age predicted
FVC 2.02 80
FEV1 1.91 91
FEV1/FVC 94
TLC 6.99 85
DLCO 2.71 37
What is the most likely diagnosis?
A. Bronchiolitis Obliterans
B. Restrictive lung disease
C. Pulmonary hypertension
D. Alveolar hemorrhage
35. A 24-year-old man presents with shortness of breath for 6 months.
A flow-volume loop is shown
How is the most likely diagnosis?
A. Bronchial asthma
B. COPD
C. ILD
D. Fixed upper airway obstruction
36. A 20-years-old woman who is known to have SLE presents
with acute shortness of breath and mild hemoptysis.
Pulmonary function test is shown.
Test Result
% predicted
Normal value
FVC 65 >80
FEV1 79 >80
FEV1/FVC ratio 90 70
DLCO 160 >80
What is the most likely Diagnosis?
A. Severe Anemia
B. Cryptogenic organizing pneumonia
C. Bronchiolitis Obliterans
D. Pulmonary alveolar hemorrhage
37. Which of the following is used to follow disease severity in
COPD patients?
a. Total lung capacity (TLC)
b. Degree of responsiveness to bronchodilators
c. Forced vital capacity (FVC)
d. Forced expiratory volume in 1 second
e. Diffusing capacity (DLCO)