What are some advantages of mandatory minute ventilation (MMV) as a weaning tool?

1. It provides greater control over PaCO2 than intermittent mandatory ventilation does.
2. It prevents acidemia with acute hypoventilation.
3. It eliminates concerns over depressant drugs.
4. It ensures an efficient pattern of ventilation.
a. 2 and 4 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 1, 2, 3, and 4

ANS: B