Comprehensive Respiratory and Burn Care Practice Test

A sudden rise in peak inspiratory pressure on the ventilator usually points to increased airway resistance or stiffer lungs that require more pressure to deliver the same volume. When secretions or mucus plug the airway, the airway becomes more obstructed, so the ventilator must push harder, and the peak pressure goes up. Bronchospasm narrows the airways as well, increasing resistance and raising the peak pressure. Endotracheal tube obstruction tightens the lumen, again increasing resistance and driving up peak inspiratory pressure.

In contrast, increased lung compliance means the lungs are easier to inflate; less pressure is needed to deliver the same tidal volume, so the peak inspiratory pressure would not rise and may even decrease.