Plateau Greater Than Peak Pressure: A Sign of Patient Inspiratory Effort

Why a plateau pressure higher than the peak signals patient inspiratory effort rather than a measurement error.

MechanicsM3M4

Fig 1.This waveform demonstrates an elevation of the plateau pressure relative to the peak pressure. In passive patients, the plateau should be lower than peak pressure. However, in the presence of inspiratory effort, some of the tidal volume is driven by negative pressure secondary to patient effort (Pimus). Unlike the positive pressure applied by the ventilator, Pimus will lower airway pressures. The higher tidal volumes obtained in the presence of inspiratory effort will raise end-inspiratory alveolar, and hence, plateau pressures. Therefore, in the presence of effort, the plateau may be higher than the peak pressure, like you see in this case. Remember, the plateau is our surrogate for end-inspiratory alveolar pressure and is determined by the volume inside the lungs/chest wall and their compliance.

Learn the concept behind this case

Comprehensive · M3 — Plateau pressure

Comprehensive · M5 — Detecting patient effort

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