Plateau pressure (PPLAT) is the pressure applied to small airways and alveoli during positive-pressure mechanical ventilation. It is measured during an inspiratory pause on the mechanical ventilator.In ARDS maintain plateau pressure <30cm of water measured on ventilator. Plateau pressure (PPLAT) is the pressure applied to small airways and alveoli during positive-pressure mechanical ventilation. It is measured during an inspiratory pause on the mechanical ventilator.In ARDS maintain plateau pressure <30cm of water measured on ventilator.