The most effective adjustment to maintain lung expansion on a conventional ventilator is to increase which parameter?

• A. Inspiratory time
• B. Peak inspiratory pressure (PIP)
• C. Positive end-expiratory pressure (PEEP)
• D. Rate

Answer: (B)

Increasing the peak inspiratory pressure delivers a higher driving force during each breath, directly increasing the volume that the lungs receive and promoting better alveolar expansion during inspiration. This makes expansion more effective on every breath. While keeping airways open at end exhalation (PEEP) helps prevent collapse between breaths, and shortening or lengthening the breath cycle (rate or inspiratory time) mainly affects ventilation timing rather than the amount of expansion achieved per breath, the biggest impact on expanding the lungs per inspiration is higher driving pressure. Of course, this must be used within safe pressure limits to avoid lung injury.