The type of breath shown in the flow-volume loop below is which of the following?

a. Pressure support ventilation (PSV)
b. Continuous positive airway pressure (CPAP)
c. Pressure-controlled continuous mandatory ventilation (PC-CMV)
d. Spontaneous without support

ANS: D
Part of the flow-volume curve occurs to the left of the y-axis; this reflects a drop in pressure dur-ing inspiration (pressure value becomes negative) and an increase in pressure with exhalation (pressure becomes positive).