For a patient receiving volume-controlled ventilation, which of the following will not result in increased mean airway pressure?

In volume-controlled ventilation, mean airway pressure is influenced by several factors related to the ventilatory settings and patient interactions. A decrease in the mandatory rate does not typically lead to an increase in mean airway pressure because it results in a longer time between breaths, allowing for more complete exhalation and decreasing the average airway pressure over time. This longer expiratory time can prevent the build-up of pressure within the airways that typically occurs with higher mandatory rates.

On the other hand, changes such as using an inspiratory pause or an expiratory retard can increase mean airway pressure because they prolong the time that the airways are under pressure during inspiration or extend the time the airways are held open, preventing early exhalation. Additionally, decreasing the inspiratory flow rate can also increase mean airway pressure by allowing gas to remain in the airways longer, thereby increasing the pressure before the ventilator allows exhalation.

Therefore, the decrease in mandatory rate is the only option that does not contribute to an increase in mean airway pressure.