Exam Questions and CORRECT Answers
Tidal Volume - CORRECT ANSWER - measured with a respirometer at bedside or
spirometry
Normal= 300-700mL
Expiratory Reserve Volume - CORRECT ANSWER - measured through spirometry from
a slow VC
Normal=1000mL and 20-25% of the VC
Residual Volume - CORRECT ANSWER - FRC-ERV
Normal=1500mL
Helium Dilution Test - CORRECT ANSWER - Close circuit system used to determine
FRC. Helium is diluted until equilibrium is reached. This normally takes 7 minutes but in
severally obstructed patients it can take 30 minutes
Nitrogen Washout Test - CORRECT ANSWER - open circuit method to determine FRC.
Occurs in 7 minutes.
Plethysmograph (Body Box) - CORRECT ANSWER - based on boyles law and may give
higher FRC number than other test
FRC - CORRECT ANSWER - normal=2500mL
Inspiratory Capacity - CORRECT ANSWER - measured from simple spirometry from VC
normal=3500mL (75-85% of the VC)