Cardiopulmonary: Lung Volumes and Capacities Flashcards
Anatomic dead space volume (VD)
Volume of air that occupies the non-respiratory conducting airways
Expiratory reserve volume (ERV)
Maximal volume of air that can be exhaled after a normal tidal exhalation.
ERV is approximately 15% of total lung volume
Forced expiratory volume (FEV)
Maximal volume of air exhaled in aa specified period of time: usually the 1st, 2nd, and 3rd second of a forced vital capacity maneuver
Forced vital capacity (FVC)
The volume of air expired during a forced maximal expiration after a forced maximal inspiration
Functional residual capacity (FRC)
Volume of air in the lungs after normal exhalation.
FRC = ERV + RV
FRC is approximately 40% of total lung volume
Inspiratory capacity (IC)
maximal volume of air that can be inspired after a normal tidal exhalation
IC = TC + IRV
IC is approximately 60% of total lung volume
Inspiratory reserve volume (IRV)
Maximal volume of air that can be inspired after normal tidal volume inspiration
IRV is approximately 50% of total lung volume
Minute volume ventilation (VE)
Volume of air expired in one minute
VE = TV x respiratory rate
Peak expiratory flow (PEF)
Maximum flow of air during the beginning of a force expiratory maneuver
Residual volume (RV)
Volume of gas remaining in the lungs at the end of a maximal expiration
RV is approximately 25% of total lung volume
Tidal volume (TV)
Total volume inspired and expired with each breath during quiet breathing
TV is approximately 10% of total lung volume
Total lung capacity (TLC)
Volume of air in the lungs after a maximal inspiration; the sum of all lung volumes
TLC = RV + VC or TLC = FRC + IC (100%)
Vital capacity (VC)
Volume change that occurs between maximal inspiration and maximal expiration
VC = TV + IRV + ERV
VC is approximately 75% of total lung volume
