Everything You Need to Know About the Plateau Pressure

Picture of the peak inspiratory pressure and plateau pressure as measured during mechanical ventilation

The plateau pressure is one of the most important parameters to monitor during mechanical ventilation.

It reflects the pressure that alveoli and small airways of the lung are exposed to during mechanical ventilation.

This article will tell you how to measure the plateau pressure, what its normal values are, and when it should be measured.

Read on for more information about plateau pressure monitoring in patients receiving mechanical ventilation.

What is the plateau pressure?

The plateau pressure reflects the pressure the alveoli and small airways of the lung are exposed to during mechanical ventilation. This is sometimes referred to as the transpulmonary pressure.

Why is the plateau pressure important?

Excessively high plateau pressures may put the patient at risk for barotrauma and atelectotrauma during mechanical ventilation.

How do I measure the plateau pressure?

The plateau pressure is measured during peak inspiration and while there is no air movement inside the lungs. To accomplish this an inspiratory pause maneuver is performed for 0.5 to 1 second at peak inspiration.

What is the difference between peak inspiratory pressure and plateau pressure?

The peak inspiratory pressure (PIP) records the highest pressure that occurs inside the lungs at peak inspiration. The PIP should always be higher than the plateau pressure because of the effect airway resistance has on the PIP as air flows through the lungs.

Airway secretions, inflammation, bronchoconstriction, and even a kinked endotracheal tube can all increase airway resistance and increase the PIP as a result.

Unlike the PIP, the plateau pressure records the pressure inside the lungs when no air is moving by performing an inspiratory pause at peak inspiration. As a result, the plateau pressure does not factor in airway resistance. The plateau simply reflects the pressure it takes to hold a given volume inside the lungs. This is the pressure the small airways and alveoli are subjected to, also known as the trans pulmonary pressure.

What are some limitations of the plateau pressure?

External chest wall pressure may give false high results. For example, the lungs of obese patients or those in the advanced stages of pregnancy may have elevated plateau pressures that do not reflect the trans pulmonary pressure (the pressure alveoli and small airways are subjected to), but rather external pressures

Other limitations may occur if the patient forcibly exhales during the inspiratory pause maneuver which may cause false high readings.

What are plateau pressure normal values?

The ARDSnet.org protocol recommends a goal of keeping the plateau pressure less than or equal to 30 cm H2O.

What causes elevated plateau pressures?

Lung conditions that stiffen the lungs, such as ARDS or pulmonary fibrosis may cause high plateau pressures during mechanical ventilation.

Inappropriate ventilator settings, particularly excessively large tidal volumes used during volume control ventilation can also increase the plateau pressure.

Are there plateau pressure questions on the NBRC RRT board exams?

Yes, there are questions related to plateau pressure on the NBRC CSE and TMC exams. For some great tips and tricks to help you pass the NBRC clinical simulations exam click HERE.

About Damon Wiseley, RRT-CPFT, B.H.S.c 9 Articles
Lead writer at Respiratory Cram RRT-CPFT B.H.S.c. Nova Southeastern University