Laboratory & Imaging: PulmonaryAnalysis of pleural fluid requires several laboratory tests, particularly those to help distinguish "transudative" from "exudative" effusion. Tests on pleural fluid that are useful in the initial work-up of a pleural effusion include:
Pulmonary Function TestsPulmonary function tests (PFTs) are useful in a variety of clinical settings:
Definitions of frequently used spirometry measures of lung function
Forced expiration (FEV)The subject inspires maximally, and then exhales as hard and completely as possible. The volume of air exhaled in the first second is called FEV1 and the total volume exhaled is the forced vital capacity (FVC). Normally the FEV1 is about 80% of the FVC.
Vital capacity (VC)The largest volume measured on complete exhalation after full inspiration.
Flow volume curvesThe first small part of air exhaled in forced expiration is due to airway collapse. Subsequently flow is limited by airway compression and is determined by the elastic recoil force of the lung and airway resistance.
Two patterns can be distinguished by these measurements: