Regarding pulmonary function test all are TRUE, EXCEPT
High-Yield Explanation
Changes in lung function tests in obstructive lung diseases- Eg: Emphysema
TLC- Increase
RV- Increase
FRC- Increase
Peak expiratory flow rate- Decrease
FEV1- Decreased out of proportion to FVC (Forced vital capacity)
Forced expiratory vital capacity (FEVC)- Normal to slightly decreased
FEV1/FEVC- Decreased (May decrease as low as 20-30%)
Changes in lung function tests in restrictive lung diseases
TLC- Decreased
RV- Decreased
FRC- Decreased
Forced mid expiratory flow rate- Decrease
FEV1- Decreased in proportion to FVC (Forced vital capacity)
Forced vital capacity (FVC)- Decreased
FEV1/FEVC- Near normal or increased.
Lung compliance- decreased
Diffusion capacity- decreased
FEV1- Forced expiratory volume in 1 second.