PFT’s - Spirometry Flashcards
Restrictive Disease Process
Decreased volumes
Obstructive Disease Process
Decreased flow rates
FVC For Obstructive Diseases
Airways constrict when flow is forced out
In Restrictive Diseases…
SVC and FVC will be equal and low
Vital Capacity
Volume of air measure from a slow, complete expiration after a maximal inspiration, without forced or rapid effort
What Affects Vt?
Age, height, sex, race
VC Should Be..
Between 80%-120% of predicted
FEV1
Forced expiratory volume in 1 second
Decreased FEV1/FVC
Decreased ratio means obstruction
FEF25%-75%
Measures airflow through the small and mid airways
FEF25%-75% in Obstructive Diseases
Will be low, normal in restrictive
Back Extrapolated Volume
Must be below 5% or 150cc
Acceptability Criteria
3 acceptable spirograms, 2 largest FVC values within 150mL, 2 largest FEV1 valued within 150mL
PEF Reflects
Patient effort
Issue in Restrictive Diseases
Volume
Issue in Obstructive Diseases
Flow
Variable INTRAthoracic Obstruction
Problem with flow on expiration
Variable EXTRAthoracic Obstruction
Problem with flow on inspiration
Pre and Post Bronchodilator Criteria
12% change and 200mL increase
Measure % Change
Post drug - pre drug x 100 / pre drug
Sarcoidosis
Restrictive disease
Which of the following will result in a decrease in compliance?
I. Edema
II. Emphysema
III. Atelectasis
IV. Pneumonia
I, II, and IV
Why should a series of peak flow measurements be reported?
A minimum of 3 values must be reported
After a resting expiration, air still remains in the lungs. What is this volume called?
FRC
A subject who complains of shortness of breath has an FVC of 2.57 L, but her SVC is 2.99. What do these findings suggest?
Emphysema - Airways collapse
