What are some key causes of patient-ventilator asynchrony and increased work of breathing dur-ing pressure-triggered volume-controlled continuous mandatory ventilation?

1. Improper trigger setting
2. Insufficient inspiratory flow
3. High peak airway pressures
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3

ANS: A
If sensitivity is set too low, such that considerable effort is necessary to trigger the ventilator, pa-tient-ventilator asynchrony occurs. A pressure sensitivity of −0.5 to −1.5 cm H2O or flow sensi-tivity of 1 to 2 L/min is regarded as optimal. Inspiratory flow must be set to meet the patient's inspiratory demand. An insufficient inspiratory flow can cause patient-ventilator asynchrony and increased work of breathing.