Spirometry Terminology
Terminology  PFT Terms FVC: Forced (expiratory) Vital Capacity = total volume exhaled forcefully from the point of maximal inhalation. FEV1: Forced Expiratory Volume during the first second of the test. FEV1%: The ratio of the FEV1 to the FVC, i.e. FEV1/FVC. Identifies the percentage of total FVC exhaled during the first second of the test. FEF2575: Traditionally known as MMEF, (Maximal MidExpiratory Flow Rate) is the average flow rate between the 25% level and 75% level of the observed FVC. eg, with an observed FVC of 4.0 liters the 25% level is at 1.0 liter and the 75% level is at 3.0 liters. A line drawn through these points on the timevolume FVC curve will display this average literspersecond flow rate. PEFR: Peak Expiratory Flow Rate in liters per Second. FEV#: Forced Expiratory Volume occurring within (0.5, 1, 3, 6) seconds. FEF##: Forced Expiratory Flow occurring at the point (25, 50, 75) that is 25%, 50%, 75% from the beginning of the exhalation. FET: Forced Expiratory Time. The total time of Exhalation expressed in seconds. TPEF: Time to Peak Expiratory Flow Rate expressed in milliseconds, from start of exhalation. VEZ%: Volume Extrapolated Zero, as a percentage of the FVC volume. It is earliest acceleration of the exhalation. PIFR: Peak Inspiratory Flow Rate (during the inspiratory part of the FVL). FIF##: Forced Inspiratory Flow rate at the point (25, 50, 75) that is 25%, 50%, 75% from the beginning of the inhalation. FIVC: Forced Inspiratory Vital Capacity (maximal inhalation beginning from the point of maximal exhalation). FVL: Flow Volume Loop PostBD: Post Bronchodilator Pred: Predicted. The normal or predicted value for a subject of that age, height, sex, and ethnicity. Meas: Measured. The subject’s measured results. %Prd: Percent of predicted. Compares the subject’s results to the predicted value for each parameter (i.e., Pred/Meas = %Pred). 

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