Pulmonary function tests measure lung volumes, gas flow rates, gas diffusion, and gas distribution to evaluate the integrity of the airways, respiratory musculature, and lung tissues. The results of these tests can classify pulmonary diseases into three categories: obstructive, restrictive, or a combination of both. Pulmonary function testing involves measurements of dynamic gas flow, lung volumes and capacities, and gas diffusion to provide a quantitative assessment of lung function.
2. Introduction:
PFT provide the clinician with information about
the integrity of the airways, the function of the
respiratory musculature, and the condition of the
lung tissues themselves.
A thorough evaluation of pulmonary function
involves several tests that measure lung volumes
and capacities, gas flow rates, gas diffusion, and
gas distribution.
Based on the results of PFTs, pulmonary
diseases may be classified into three basic
categories: obstructive, restrictive, or
combined.
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2 Didhiti Desai
3. Introduction:
There are three categories of pulmonary function
tests, measuring
1. Dynamic flow rates of gases through the
airways,
2. Lung volumes and capacities
3. The ability of the lungs to diffuse gases.
A combination of these measurements provides a
quantitative picture of lung function
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3 Didhiti Desai
5. Purposes/Indications:
To identify and quantify changes in pulmonary
function.
To evaluate need and quantify therapeutic
effectiveness.
To perform epidemiologic surveillance for
pulmonary disease
To assess patients for risk for postoperative
pulmonary complications.
To determine pulmonary disability.
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5 Didhiti Desai
6. Contraindications:
Patients with acute, unstable cardiopulmonary
problems, such as hemoptysis, pneumothorax,
myocardial infarction, pulmonary embolism, and
patients with acute chest or abdominal pain
should not be tested.
Patients who have nausea and who have recently
vomited should not be tested because there is a
risk of aspiration.
Pulmonary function testing requires patient effort
and cooperation.
Patients with dementia or confusion may not
achieve optimal or repeatable results 19 March 2023
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7. Pathophysiologic Patterns:
Pulmonary function testing provides the basis for
classifying pulmonary diseases into two major
categories, obstructive pulmonary disease and
restrictive pulmonary disease.
These two types of lung diseases sometimes
occur together as a mixed impairment.
Obstructive and restrictive types of lung diseases
differ in several important ways.
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