Module 4: Physiology of the Respiratory System - Non-Obstructive Reduction In Lung Volumes (Restriction).

Non-Obstructive Reduction In Lung Volumes (Restriction):

Restriction implies both a reduced TLC and RV. RV is not measured by spirometry. Restriction results in a reduced vital capacity, which is measured by spirometry.

Flow characteristics are normal or supra-normal.

The figure on the right above illustrates a F/V curve that may be encountered in a fibrotic lung disease such as asbestosis.

The shape of the curve resembles a normal curve, indicating that flow is not impaired. The important abnormality is that the curve is small, that is, there is a reduced FVC.