An increasing peak inspiratory pressure may indicate which of the following?

• A. Decreasing lung compliance
• B. Increasing lung compliance
• C. Decreased respiratory rate
• D. Decreased tidal volume

Answer: (A)

Rising peak inspiratory pressure happens when the lungs become stiffer and less able to expand. When lung compliance decreases, the same tidal volume requires more force to overcome elastic recoil, so the ventilator must generate higher pressure to deliver that volume, raising the peak inspiratory pressure. If compliance improves, the required pressure drops. Rate or tidal volume changes don’t directly cause higher peak pressure in the same way; a higher PIP most directly signals reduced lung compliance.