Lecture 2/3 Flashcards
Two lung function tests
- spirometry
- peak flow meters
how many times do you need to do spirometry to confirm results
three times
three stages of spirometry
regular breathing, deep breath in, big blow out
4 variables healthy lung size and function is dependent on
age, sex, height, race
three numeric values of clinical importance for interpretation
1) Forced vital capacity (FVC)
2) forced expiratory volume in the first second (FEV1)
3) FEV1/FVC ratio
Forced vital capacity FVC
total amount of air that can be expelled from full lungs
FEV1
the amount of air expelled during the first second of the spirometry maneuver
FEV1/FVC
The fraction of air exhaled in the first second relative to the total exhaled
Vital Capacity
a volume of a full breath exhaled in the patient’s own time and not forced
Reversibility Testing
determination of airflow limitation reversibility using drug administration.
Why is reversibility testing done
to detect patients with reversible airway obstruction
Reversibility is positive if
FEV1 changes by ~12% and FVC changes by ~200mL
what is administered prior to reversibility testing
larger doses of bronchodilators
3 limitations of spirometry
pt needs to show effort and cooperation
clinical context is important (need suspicion to get spirometry)
normal values may not be reflective
age for spirometry
6 years and over
