A comparison of functional residual capacity measured by body plethysmography with that measured by
nitrogen washout reveals that the measurement obtained during the nitrogen washout test is less than that during body plethysmography. This discrepancy is most likely caused by which of the following?
a. Poor technique c. Restrictive lung disease
b. Severe air-trapping d. Directional valve malfunction
ANS: B
Severe air-trapping will produce lower functional residual capacity results than body plethys-mography because the nitrogen washout test measures gas volumes only in communicating air-ways.
You might also like to view...
The concentration of oxygen leaving an oxygen concentrator depends on the:
a. number of sieves in the unit. b. number of compressors used. c. set flow rate of the gas exiting. d. size of the sodium-aluminum silicate pel-lets.
Disasters ____.
A. have long-term consequences but not short-term ones B. may be natural or man-made C. arise from natural causes, except for the weather D. do not lead to further disasters