How can you ensure reliability when measuring the expiratory reserve volume (ERV)?
a. Have the patient perform the maneuver twice, ensure consistency, and then take the best value.
b. Have the patient perform the maneuver three times, and then take the last value.
c. Have the patient perform the maneuver twice, ensure consistency, and then take the mean value.
d. Have the patient perform the maneuver until he or she becomes fatigued, and then take the last value.
Question 2
In both the helium dilution test and nitrogen washout functional residual capacity (FRC) deter-minations, at what point should the patient normally be connected to the system to begin the test?
a. Resting expiration
b. Full forced inspiration
c. Resting inspiration
d. Full forced expiration