Pulmonary function tests (PFTs) objectively evaluate lung function by measuring lung volumes, airway function, and gas exchange. PFTs can detect and monitor lung disease, evaluate pre-operative risk, and assess health status. Tests include forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the FEV1/FVC ratio. FVC measures total air volume exhaled forcefully, while FEV1 measures the volume exhaled in 1 second. Disease is categorized as obstructive, restrictive, or mixed based on PFT results. Tests must meet acceptability criteria including good start, no coughing or variable flow, and test reproducibility. PFTs provide important

1. JAMIA MILLIA ISLAMIA
CENTRE OF PHYSIOTHERAPYAND REHABILITATION SCIENCES
TOPIC – PFT INTERPRETATION
PHYSIOTHERAPY IN CARDIOPULMONARY CONDITIONS (402)
SUBMITTED TO: DR. JAMALALI MOIZ
SUBMITTED BY: AZIZA NAZNEEN
BPT IV YEAR

2. Pulmonary function test
• Pulmonary function testing is a group of tests
that provide objective data on a patient's lung
function
• Evaluates 1 or more major aspects of the
respiratory system
– Lung volumes
– Airway function
– Gas exchange
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3. Indications
• Detect disease
• Evaluate extent and monitor course of disease
• Evaluate treatment
• Assess pre operative risk.
• Assess prognosis.
• Assess health status before beginning strenous
activity or procedure
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4. Contraindications
• Hemoptysis of unknown origin.
• Unstable angina pectoris.
• Recent MI.
• Thoracic aneurysm.
• Cerebral aneurysm.
• Abdominal aneurysm.
• Recent eye surgery.
• Recent abdominal and thoracic surgery.
• Patient with a history of syncope.
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5. Technique
• 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
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6. Terminology
• 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)
• Interpretation of % predicted:
– 80-120% Normal
– 70-79% Mild reduction
– 50%-69% Moderate reduction
– <50% Severe reduction
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7. • 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
• Interpretation of % predicted:
– >75% Normal
– 60%-75% Mild obstruction
– 50-59% Moderate obstruction
– <49% Severe obstruction
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8. FEV1 FVC
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9. Categories of diseases
• Obstructive
• Restrictive
• Mixed
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12. Acceptability Criteria
• Good start of test
• No coughing
• No variable flow
• No early termination
• Reproducibility
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13. References
1. Miller MR, Crapo R, Hankinson J, et al. General
considerations for lung function testing. Eur
Respir J 2005
2. Wanger J, Clausen JL, Coates A, et al.
Standardisation of the measurement of lung
volumes. Eur Respir J 2005;
3. American Thoracic Society. Lung Function
Testing: Selection of Reference Values and
Interpretative Strategies. Am Rev Respir Dis
1991
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