Peak and plateau pressures

Relationship between tidal volume and airway pressure during mechanical ventilation. The inspiratory plateau in the volume tracing is achieved by temporary occlusion of the expiratory limb of the ventilator circuit. During this period, airway pressure falls from a peak of 20 cmH₂O to a plateau pressure of 10 cmH₂O. These measurements allow the calculation of respiratory system (or thoracic) compliance. The static compliance of the respiratory system is equal to the exhaled tidal volume divided by the difference between plateau and positive end-expiratory pressures (Crs = Vt / Plat-PEEP). An increase in the difference between peak and plateau pressures implies increased airway resistance.