Driving Pressure Calculator
Driving Pressure Calculator
Driving pressure is plateau pressure minus TOTAL PEEP — the tidal pressure swing across the respiratory system, and the variable that carried the mortality signal in Amato’s analysis of nine ARDS trials.
Driving pressure
Plateau minus total PEEPPlateau 26 cmH₂O, total PEEP 12 cmH₂O, tidal volume 400 mL
Formula
equivalently ΔP = VT ÷ CRS
- Pplat
- plateau pressure in cmH₂O, from an end-inspiratory hold. Amato’s paper is explicit that driving pressure can be calculated as plateau minus PEEP only for patients making no inspiratory efforts, and the analysis excluded patients on pressure support or breathing above the set rate
- PEEPtot
- TOTAL PEEP: set plus intrinsic, from an expiratory hold. Substituting the set value understates driving pressure by exactly the auto-PEEP
- the identity
- ΔP equals tidal volume divided by respiratory-system compliance, which is why Amato describes it as a tidal volume normalised to the aerated lung rather than to the lung a healthy person would have. Two patients on the same mL/kg can sit at very different driving pressures
- static, not dynamic
- peak minus PEEP is a DYNAMIC driving pressure and a different quantity: it contains flow-resistive pressure. It has been studied in its own right — Rauf and colleagues found a ROC-identified 19 cmH₂O in children — but it is not the variable the adult 15 cmH₂O conversation is about
Worked example
Plateau 26 cmH₂O, total PEEP 12 cmH₂O, tidal volume 400 mL
ΔP = 26 − 12 = 14.0 cmH₂O
Compliance implied = 400 ÷ 14 = 28.6 mL/cmH₂O
Now suppose an expiratory hold shows 4 cmH₂O of intrinsic PEEP, so total PEEP is 16: ΔP becomes 10.0 cmH₂O and compliance 40.0. Using set PEEP overstated the driving pressure by 40%
Suppose instead the number entered as a plateau was really the peak of 33: ΔP would read 21.0 against the true 14.0 — a 7 cmH₂O error, exactly the increment Amato associated with a relative risk of 1.41
Reduce the tidal volume to 320 mL at the same compliance and ΔP is 11.2; in Amato's trials a change in tidal volume was associated with survival only when it was one of the changes that lowered ΔP
What the evidence says, and in whom
| Source | Population | Finding |
|---|---|---|
| Amato and colleagues, NEJM 2015 | 3,562 patients, 9 randomised ARDS trials, all passive | Relative risk of death 1.41 (1.31 to 1.51) per 7 cmH₂O, no threshold stated. Tidal volume and PEEP helped survival only when they reduced ΔP |
| Chen and colleagues, Emerg Med Int 2019 | 7 studies, 8,010 patients with ARDS | Pooled risk ratio 1.10 (1.05 to 1.16) for higher versus lower ΔP; the association held in mild-to-severe but not in the moderate-to-severe subgroup |
| Aoyama, Yamada and Fan, J Intensive Care 2018 | Commentary on their own meta-analysis | Suggest targeting ΔP below 13 to 15 cmH₂O, while stating that how best to achieve it is unclear |
| ESICM 2023 and ATS 2024 guidelines | Adults with ARDS | 4 to 8 mL/kg predicted body weight strongly recommended, plateau under 30. Driving pressure mentioned and left unresolved: no recommendation |
| Non-ARDS and obese populations | Post-operative, obstructive, obese | The mortality association has not been reproduced. In high chest-wall elastance, transpulmonary pressure is the better surrogate of lung stress |
The three pressures, and which goes in which slot
| Pressure | How it is obtained | Used for |
|---|---|---|
| Peak inspiratory | On the screen, no manoeuvre | Dynamic compliance and, with flow, airway resistance. NOT driving pressure |
| Plateau | End-inspiratory hold, 2 to 3 s, passive patient | Static compliance and driving pressure |
| Total PEEP | End-expiratory hold | The subtrahend in driving pressure and in both compliances |
Plateau minus total PEEP, and why both words matter
Driving pressure is the pressure swing the respiratory system sees with each tidal breath: the plateau pressure, which is elastic recoil at end-inspiration, minus the pressure the system is already held at during expiration. Written the other way round it is tidal volume divided by respiratory-system compliance, and that identity is why it attracted attention. A tidal volume of 6 mL/kg predicted body weight is a dose scaled to the lung the patient would have had if healthy. Driving pressure scales the same breath to the lung they have now, so two patients on identical settings can sit at 10 and at 20 cmH₂O.
Amato and colleagues analysed 3,562 patients from nine randomised ARDS trials and found that each 7 cmH₂O increment carried a relative risk of death of 1.41, and — the part most often dropped — that changes in tidal volume or PEEP after randomisation were associated with survival only when they were among the changes that reduced driving pressure. What that paper did not do is name a threshold. The 13 to 15 cmH₂O figure quoted everywhere comes from later meta-analytic work, and the authors who proposed it said in the same breath that how to reduce driving pressure at the bedside is unclear. Neither the ESICM nor the ATS guideline makes a recommendation about it.
Two measurement details decide whether the number means anything. The PEEP in the formula is TOTAL PEEP, not the value set on the dial: intrinsic PEEP from incomplete emptying adds to it and only an expiratory hold shows it, so in air trapping the set value gives a driving pressure too large by exactly the auto-PEEP. And the plateau has to be a plateau — an end-inspiratory hold, a flat trace, a passive patient. Amato’s own conclusions are stated as valid only for ventilation in which the patient is making no respiratory effort. Beyond that, driving pressure spans lung and chest wall together, which is why it has lost its prognostic value in obese cohorts.
This supports a clinician’s judgement rather than replacing it.
Frequently asked questions
What is driving pressure?
Plateau pressure minus total PEEP: the tidal pressure swing across the respiratory system, in cmH₂O. Equivalently tidal volume divided by respiratory-system compliance, which makes it a tidal volume normalised to the size of the lung actually being ventilated.
Is 15 cmH₂O a safe limit for driving pressure?
There is no established limit. Amato’s analysis reported a continuous relationship and named no threshold; the 13 to 15 cmH₂O figure comes from later meta-analytic work whose authors called its achievement unclear. No randomised trial has tested a driving-pressure-targeted strategy, and neither the ESICM nor the ATS guideline recommends a target.
Should I use set PEEP or total PEEP?
Total PEEP, from an end-expiratory hold. Set PEEP plus intrinsic PEEP is what the respiratory system is actually held at, and in a patient with air trapping the set value overstates driving pressure by exactly the auto-PEEP.
Can I use peak pressure instead of the plateau?
No. Peak minus PEEP is a dynamic driving pressure containing the pressure spent on airway resistance, so it overstates the elastic swing. It has been studied separately — a paediatric cohort identified 19 cmH₂O on a ROC curve — but it is not the quantity the adult ARDS evidence is about.
Does driving pressure mean the same thing in obesity?
Not reliably. Driving pressure spans lung and chest wall together, so where chest-wall elastance is high much of it distends the chest wall rather than the lung. Studies in obese patients have found it to lose prognostic value, and transpulmonary pressure from an oesophageal balloon is the better surrogate of lung stress there.
Related calculators
References
- Amato MBP, Meade MO, Slutsky AS, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med. 2015;372(8):747–55.
- Chen Z, Wei X, Liu G, et al. Higher vs. lower DP for ventilated patients with acute respiratory distress syndrome: a systematic review and meta-analysis. Emerg Med Int. 2019.
- Aoyama H, Yamada Y, Fan E. The future of driving pressure: a primary goal for mechanical ventilation? J Intensive Care. 2018;6:64.
- Life in the Fast Lane Critical Care Compendium. Driving pressure. litfl.com
- Rauf A, Sachdev A, Venkataraman ST, Dinand V. Dynamic airway driving pressure and outcomes in children with acute hypoxemic respiratory failure. Respir Care. 2021;66(3):403–9.
- Crítica e Ciências da Saúde / Critical Care Science. Application of new ARDS guidelines at the bedside. 2025. scielo.br
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/