The ventilator is set to CMV with tidal volume 500 mL, rate 20/min, FiO2 1.0, PEEP 5 cm H2O. What is the delivered minute volume?

• A. - 10 L
• B. 50 L
• C. 100 L
• D. 25 L

Answer: (A)

Minute volume is the amount of air delivered each minute and is calculated by multiplying the tidal volume by the respiratory rate. In CMV, the ventilator provides a fixed tidal volume on every breath, so the minute volume depends only on those two settings. With a tidal volume of five hundred milliliters per breath and a rate of twenty breaths per minute, the calculation is five hundred milliliters per breath times twenty breaths per minute, which equals ten thousand milliliters per minute — ten liters per minute. FiO2 and PEEP affect oxygen delivery and airway pressures but do not change the basic minute volume. The dash seen in the option is just formatting; the delivered minute volume is ten liters per minute.