Spirometry Flashcards
Spirometric measures:
Vital capacity
Max volume of air that can be expired or inspired during a forced (FVC) or slow (SVC) manoeuvre
units = litres
FVC = forced vital capacity
Spirometric measures:
FEV1
Forced expired volume in the first sec of maximal expiration following a maximal inhalation
units = litres
Spirometric measures:
FEV1 / FVC %
FEV1 expressed as % of FVC
- useful for looking at airway resistance
units = %
Spirometric measures:
Maximal voluntary ventilation
Max volume of air that can be inspired and expired in one minute
- useful for looking at breathing reserve in VO2max testing
units = l.min-1
Spirometric measures:
FEF25-75%
The average expired flow over the middle half of the breath
- Useful for looking at small airway flows
Units = l.min-1
Spirometric measures:
Peak expiratory flow
Max expiratory flow rate achieved in early part of expired breath
- Useful for looking at airway resistance
Units = l.min-1
Spirometric measures:
Tidal volume
Volume of air inspired and expired at the prevailing physiological conditions, without attempting to perform max manoeuvre
Units = litres
Spirometric measures:
Inspiratory reserve volume
Inspiratory reserve at the end of a normal (tidal) inspiration
Units = litres
Spirometric measures:
Expiratory reserve volume
Expiratory reserve at the end of a normal (tidal) expiration
Units = litres
Spirometric measures:
Residual lung volume
Volume of air in lungs at the end of a maximal expiration
Units = litres
- Not measured by normal spirometry
Spirometric measures:
Functional residual capacity
total amount of air remaining in the lungs after a normal (tidal) expiration
Units = litres
Spirometric measures:
Total lunge capacity (TLC)
TLC = VT + IRV + ERV
TLC = VC + RV
TLC = IC + FRC
