Based on the outcomes of the study performed by Ranieri, what should the therapist expect when mechanical dead space is added to the breathing circuit of a patient receiving PAV?

A. decreased VT and increased respiratory rate
B. decreased respiratory rate and increased PaCO2
C. no change in either the respiratory rate or VT
D. increased likelihood of apneas and periodic breathing

?ANS: A
A. Correct response: When mechanically ventilated patients about to be weaned were challenged with mechanical dead space to increase the PaCO2, patients ventilated with PAV experienced a decreased VT and an increased respiratory rate.
B. Incorrect response: See explanation A.
C. Incorrect response: See explanation A.
D. Incorrect response: See explanation A.