Answer to Question 1
ANS: B
The pressure-time product is a way of estimating the contributions of the diaphragm during in-spiration. It is probably a better indication of a patient's effort to breathe than measurement of work derived from pressure-volume curves. Airway resistance is a measure of how much opposi-tion there is to gas movement through the airways. An increase in airway resistance will cause the diaphragm to work harder. However, airway resistance is not a direct way of assessing the func-tion of the diaphragm. Maximum inspiratory pressure provides nonspecific information about the function of the respiratory muscles in general, not specifically the diaphragm.
Answer to Question 2
ANS: C
Intrinsic work of breathing is a result of work done to overcome normal elastic and resistive forces and work to overcome a disease process affecting normal workloads in the lungs and thorax. Airway resistance is the opposition to airflow from nonelastic forces of the lung. Dynam-ic compliance is a measurement of the ease of movement of gas through the airways. The work of breathing is a result of the airway resistance, dynamic compliance, and static compliance.
