Why is it important to monitor peak and plateau pressures in mechanical ventilation?

Updated: Apr 11, 2019
  • Author: Christopher D Jackson, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Answer

Answer

After a tidal volume is selected, the peak airway pressure necessary to deliver a single breath should be determined. As the tidal volume increases, so does the pressure required to force that volume into the lung. Persistent breath-to-breath peak pressures greater than 45 cm water are a risk factor for barotrauma (see Complications of Mechanical Ventilation). The tidal volume suggested by the above rules may need to be decreased in some patients to keep the peak airway pressure less than 45 cm water (see image below).

The components of mechanical ventilation inflation The components of mechanical ventilation inflation pressures. Paw is airway pressure, PIP is peak airway pressure, Pplat is plateau pressure.

Some researchers have suggested that plateau pressures should be monitored as a means to prevent barotrauma in the patient with ARDS. Plateau pressures are measured at the end of the inspiratory phase of a ventilator-cycled tidal volume. The ventilator is programmed not to allow expiratory airflow at the end of the inspiration for a set time, typically half a second. The pressure measured to maintain this lack of expiratory airflow is the plateau pressure. Barotrauma is minimized when the plateau pressure is maintained at less than 30 cm water (see image above). Monitoring the peak and plateau pressures allows physicians to make clinical judgments on the progress of their patient (see image below).

The effects of decreased respiratory system compli The effects of decreased respiratory system compliance (A) and increased airway resistance (B) on the pressure-time waveform.

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