Driving Pressure and Plateau Pressure: The Two Numbers That Tell You How Hard the Lung Is Being Stretched

Part of the ICU Emergencies Hub — browse every related guide in one place.

Updated July 2026  |  More ICU clinical guides →

Peak pressure gets all the attention because it sets off the alarm, but it is not the number that best predicts lung injury. Two quieter measurements — plateau pressure and driving pressure — describe how much stress the delivered breath actually places on the lung tissue itself. Understanding them turns a nurse from someone who silences a high-pressure alarm into someone who can say why the lung is at risk and what to change. This guide covers what each measures, how the plateau is obtained, why driving pressure matters, and the targets to protect.

Peak vs plateau — why the difference matters

Peak inspiratory pressure is the highest pressure during a breath, and it includes the pressure needed to push gas through the airways and endotracheal tube (resistance) plus the pressure to inflate the alveoli (elastic recoil). Plateau pressure isolates just the alveolar part. You obtain it with an inspiratory-hold (end-inspiratory pause) maneuver in a passive patient: flow stops, resistance drops out of the equation, and the pressure settles to a plateau that reflects true alveolar stretch. That is why a high peak with a normal plateau points to a resistance problem (secretions, bronchospasm, a bitten or kinked tube), while a high peak with a high plateau points to a compliance problem (stiff lungs — ARDS, edema, pneumothorax, or over-distension).

Driving pressure — the lung-stretch number

Driving pressure is simply plateau pressure minus PEEP (ΔP = Pplat − PEEP). Conceptually, PEEP is the pressure the lung already holds at rest, and the plateau is the pressure at full inflation — so their difference is the actual pressure swing, or "stretch," the lung experiences with every single breath. It has emerged as one of the strongest ventilator-derived predictors of outcome in ARDS: for a given tidal volume, patients ventilated with a lower driving pressure tend to do better. The reason it outperforms tidal volume alone is that it accounts for how much healthy, aerated lung a patient actually has. In ARDS the "baby lung" is small, so the same tidal volume can over-stretch it; driving pressure captures that mismatch because a stiffer lung with less aerated volume produces a bigger pressure swing for the same breath.

Compliance, in one line

These numbers also let you track static compliance = tidal volume ÷ driving pressure. A falling compliance (rising driving pressure for the same tidal volume) means the lung is getting stiffer — worsening ARDS, developing edema, a new pneumothorax, or progressive hyperinflation. Trending compliance shift by shift is a sensitive early read on whether the lung is improving or deteriorating, often before the chest film or the gas changes much.

What to protect, and what to change

The lung-protective targets to keep in mind are a plateau ≤ 30 cm H2O and a driving pressure ≤ 15 cm H2O, layered on top of low tidal volumes (around 4–8 mL/kg of predicted body weight). When either number climbs, the levers are to lower the tidal volume, optimize PEEP (too little leaves lung collapsed and stiff; too much over-distends and can paradoxically raise driving pressure), treat the underlying process, and rule out reversible causes such as secretions, a pneumothorax, or auto-PEEP. Because PEEP appears in the driving-pressure equation, changing it is not automatically protective — the goal is the PEEP that gives the lowest driving pressure for that patient, which is exactly why nurses trend these numbers during a PEEP titration.

Where to go from here

Build on this with the lung-protective ventilation guide, the PEEP titration guide, recruitment maneuvers, and the ventilator alarm troubleshooting guide for sorting a high-pressure alarm at the bedside.