Lung Capacities, Volumes, and Sounds Flashcards
Anatomic Dead Space Volume (VD)
Volume of air that occupies non-respiratory conducting airways.
Expiratory Reserve Volume (ERV)
Max volume of air that can be exhaled after a normal tidal exhalation. ERV is ~15% of total lung volume.
Forced Expiratory Volume (FEV)
Volume of air expired during a forced max expiration after a forced max inspiration.
Functional Residual Capacity (FRC)
Volume of air in the lungs after normal exhalation.
FRC = ERV + RV
~40% total lung volume
Inspiratory Capacity (IC)
Max volume of air that can be inspired after a normal tidal exhalation.
IC = TV + IRV
~60% of total lung volume
Inspiratory Reserve Volume (IRV)
Max volume of air that can be inspired after normal tidal volume inspiration.
~50% of total lung volume
Minute Volume Ventilation (VE)
Volume of air expired in 1 minute.
VE = TV x respiratory rate.
Peak Expiratory Flow (PEF)
Max flow of air during beginning of a forced expiratory maneuver.
Residual Volume (RV)
Volume of gas remaining in the lungs at the end of a maximal expiration.
~25% of total lung volume
Tidal Volume (TV)
Total volume inspired and expired with each breath during quiet breathing.
~10% of total lung volume
Total Lung Capacity (TLC)
Volume of air in lungs after a maximal inspiration. Sum of all lung volumes.
TLC = RV + VC
TLC = FRC + IC
Vital Capacity (VC)
Volume change that occurs between maximal inspiration and maximal expiration.
VC = TC + IRC + ERV
~75% of total lung volume.
Adventitious Breath Sounds
Abnormal breath sounds
Crackle (rales)
Discontinuous, high-pitched popping sound heard more during inspiration.
Pleural Friction Rub
Dry, crackling sound during both inspiration and expiration.
