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Biogenics Research Institute
Other Respiratory Tract Disorders
Hypersensitivity Pneumonitis
Idiopathic Intersitial Lung Disease

Pulmonary Function Tests (PFT)

Pulmonary function tests are central to establishing the type of lung disorder during the diagnostic phase. They may prove very useful during environmental (natural) avoidance-challenge techniques to determine causative environments and effectiveness of remediation efforts. These tests may be the only effective measurement of progression or non-progression as the patient is followed over time.


Spirometry This is the most common pulmonary function test that is utilized to determine if there has been any damage done to the lung. There are 4 important measurements of spirometry that are very useful in the diagnosis, treatment, and monitoring of respiratory tract disorders caused by an environmental contamination. These measurements include Forced Vital Capacity (FVC), Forced Expiratory Volume 1 (FEV1) , FEV1/FVC ratio and the same values after response to bronchodilator. This response should be measured to determine if these medications would be helpful. Many patients with a variety of pulmonary disorders may have a bronchospastic component.


Forced Vital Capacity (FVC) This is a component of spirometry that measures the amount of air expelled when taking a deep breath and forcibly blowing out as much air as possible. The FVC is usually abnormal in the interstitial lung diseases. Early in the course of many cases of interstitial lung disease FVC may be within normal range. Some cases may persist for years on treatments without developing an abnormality of FVC. The FVC generally declines with progression of illness.


Forced Expiratory Volume 1st second (FEV1) This is a component of spirometry that measures the amount of air expelled in the 1st second of the forced vital capacity (FVC). The FEV1 is a measure of obstruction to air flow and is usually normal in interstitial lung disease. 

FEV1/FVC ratio This ratio is helpful in differentiating between obstructive lung diseases (emphysema and asthma) and the restrictive lung diseases. The ratio is reduced in the obstructive lung diseases and may be better than predicted normal in the restrictive diseases.


Response to Bronchodilators This response should be measured to determine if a bronchodilater would be helpful in a symptomatic fashion. Many patients with an inflammatory lung disorder may have a non-specific reactive lower airway manifested by cough, chest tightness, mucous production, and wheezing.


Total Lung Volumes These measurements become important during the diagnosis phase of an evaluation to differentiate between an obstructive defect with air trapping and a true reduction in total lung capacity. Total lung volumes are usually reduced in interstitial lung diseases and may be increased in obstructive lung diseases.


Diffusion Studies These measurements may be done at rest and with exercise. Diffusion tests measure the ability to move gases (oxygen and carbon dioxide) from inside the lung to inside the bloodstream. Diffusion studies are usually reduced in interstitial lung diseases and may be reduced in severe obstructive lung diseases, as well.