Which of the following statements are true regarding the use of controlled ventilation?

1. May allow the muscles of breathing to rest.
2. Can use larger 1:E ratio and may improve oxygenation.
3. Requires use of paralytic agents in spontaneously breathing patients.
4. Therapist has little control of needed inspiratory flow and pressure.
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only

ANS: B
Advantages of controlled ventilation include eliminating the work of breathing and complete control over the patient's inspiratory and expiratory time, flow, and pressure. In cases in which the work of breathing is high, controlled ventilation may allow for ventilatory muscle rest, reduce the O2 consumption of the ventilatory muscles, and "free up" O2 for delivery to the tissues. Con-trolled ventilation may allow prolonged inspiratory times and the use of 1:E ratios greater than 1:1 in cases in which other methods have failed to improve oxygenation. Disadvantages of con-trolled ventilation include the need for sedatives and perhaps paralytic drugs in the care of pa-tients with spontaneous breathing efforts. The administration of paralytic agents has been associ-ated with the development of prolonged neuropathy in some patients. Paralytic agents have no effect on the patient's level of consciousness and should not be given without concurrent and appropriate sedation. In addition, in the care of apneic patients, ventilator malfunction or dis-connection can lead to death of the patient.