What does a flow volume loop tell you?
) displays airflow (in L/second) as it relates to lung volume (in L) during maximal inspiration from complete exhalation (residual volume [RV]) and during maximum expiration from complete inhalation (TLC).
What does FEF 25 75 mean?
Forced expiratory flow at 25 and 75% of the pulmonary volume (FEF25-75%) is defined as the mean forced expiratory flow during the middle half of the FVC and measures average flow rates on an FVC segment that includes flow from medium-to-small airways .
What is the importance of flow volume loops?
Upper airway obstruction is an important but often unrecognised cause of dyspnoea and ventilatory failure. Flow volume loop remains the most sensitive method to detect upper airway obstruction.
Is pulmonary fibrosis restrictive or obstructive?
Examples of restrictive lung diseases include asbestosis, sarcoidosis and pulmonary fibrosis.
What is the general term for all lung diseases that cause a reduction in lung volumes without a reduction in flow rates?
Restrictive lung diseases are characterized by reduced lung volumes, either because of an alteration in lung parenchyma or because of a disease of the pleura, chest wall, or neuromuscular apparatus.
What are the features of the flow-volume loop?
Characteristic features of restrictive lung disease in the flow-volume loop include the following: 1 Low tidal volume 2 Rapid decrease in inspiratory flow 3 Rapid expiratory flow, with a high peak expiratory flow rate (as the inelastic lung recoils) More
How is the turbine related to the flow-volume loop?
The turbine gives rise to a controllable and adjustable inspiratory flow (you can have whatever flow pattern you want!). The inspiratory flow part of the loop is therefore more reflective of lung compliance: as the lung distends, the flow decreases.
Which is an example of an intrathoracic flow-volume loop?
During expiration the tumor is pushed into the trachea with partial obstruction and flattening of the expiratory part of the F/V loop. This can be both intrathoracic as extrathoracic. The flow-volume loop is typically flattened during inspiration and expiration. Examples are tracheal stenosis caused by intubation and a circular tracheal tumor.
When does a flow-volume loop appear in spirometry?
This type of flow-volume loop is typically found in younger subjects and more often in females than in males. Longitudinal studies have shown that this feature often disappears with increasing age even when spirometry results remain normal.