Answer to Question 1
ANS: B
NIV can cause excessive drying of the nasal mucosa, which has been associated with nasal con-gestion and increased nasal resistance. A heated humidifier can significantly reduce the dryness that causes congestion. Use of an HME is inappropriate, because it would lead to increased WOB.
Answer to Question 2
ANS: C
In all modes of bilevel positive-pressure ventilation, the patient's delivered VT depends on the gradient between the IPAP and EPAP, the inspiratory time, and the patient's inspiratory effort and lung characteristics.