The best method for accurately measuring the thoracic gas volume of a patient with emphysema is:
A) helium dilution.
B) nitrogen washout.
C) pressure plethysmography.
D) chemiluminescence monitoring.

Question

Quizplus · Accepted Answer

Inert gas techniques,such as helium dilution and nitrogen washout,can measure gas volumes only in communicating airways.Body plethysmography measures all of the volume in the thorax.Therefore,inert gas measurements of functional residual capacity (FRC)for a patient with chronic obstructive pulmonary disease and severe air trapping will be lower than functional residual capacity measurements obtained during body plethysmography.

The Best Method for Accurately Measuring the Thoracic Gas Volume