However, after having performed and monitored flow-volume loops
for lung transplant patients for 25 years, I have observed that even a 5 percent change in FEF25-75 can indicate beginning OB with associated lung transplant rejection.
showed a limited flow during both inspiration and expiration with flattening of both inspiratory and expiratory components, suggesting a fixed airway obstruction.
In the helium iso-flow maneuver, after the patient has taken in the three large breaths of heliox, the flow-volume loop
The inspiratory volume per second calculated from a flow-volume loop
quantifies an eventual laryngeal obstruction during inspiration and permits followup after treatment.
It is a wonder that by just glancing at a flow-volume loop
, for example, without regarding the numbers, we can ascertain so much information about a patient's lung function: restriction versus obstruction and degree, response to bronchodilator, fixed versus variable extra thoracic airway obstruction, patient effort and consistency, indication of sleep apnea, indication of lung rejection, and lung hyper reactivity.
Documentation of upper airway obstruction in unilateral vocal cord paralysis: Flow-volume loop
studies in 43 subjects.