A patient on mechanical ventilation has a plateau pressure of 32 cm H2O. What is the most appropriate initial adjustment?

• A. Increase tidal volume to improve ventilation
• B. Sedate deeper to lower plateau pressure
• C. Increase PEEP to 40 cm H2O
• D. Reduce tidal volume to achieve plateau pressure ≤30 cm H2O

Answer: (D)

Plateau pressure reflects the pressure in the alveoli during an inspiratory hold and indicates the stress the ventilator is placing on the lungs. The goal of lung-protective ventilation is to keep this pressure at or below about 30 cm H2O to reduce the risk of volutrauma and barotrauma. A plateau pressure of 32 cm H2O is slightly above that safe threshold, so the most appropriate first step is to lower the tidal volume to bring plateau pressure down to ≤30 cm H2O. After reducing tidal volume, reassess and adjust to maintain adequate ventilation, such as increasing the inspiratory rate if needed to preserve minute ventilation.

Increasing tidal volume would raise plateau pressure further, which is undesirable. Increasing PEEP tends to raise plateau pressure and is not the first move when the plateau is already high. Deepening sedation does not reliably lower plateau pressure and does not address the mechanical stress on the lung.