Which of the following is true when comparing dilutional lung volumes with body plethysmography in subjects who have severe obstruction? A) N₂ washout overestimates TLC. B) He rebreathing underestimates TLC. C) Single-breath washout compares favorably with plethysmography. D) Closed-circuit method overestimates FRC.

Question

Quizplus · Accepted Answer

In subjects with severe obstruction, body plethysmography is the preferred method for measuring lung volumes as dilutional techniques may underestimate TLC. The He rebreathing technique specifically has been shown to underestimate TLC in this population. Therefore, choice B is correct. Choices A, C, and D are incorrect.

Which of the Following Is True When Comparing Dilutional Lung