How to measure driving pressure in patients on assisted ventilation

Articolo

Autore: Jean-Michel Arnal, Hopital Sainte Musse, Toulon, France

Data: 18.09.2025

Static driving pressure should be systematically monitored at the bedside, but how do we measure it?

What is static driving pressure?

In mechanically ventilated patients using assisted modes, static driving pressure (∆P_STAT) is independently associated with ICU survival (Bellani G, Grassi A, Sosio S, et al. Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome. Anesthesiology. 2019;131(3):594-604. doi:10.1097/ALN.00000000000028461, Grassi A, Bianchi I, Teggia Droghi M, et al. Increased Driving Pressure During Assisted Ventilation for Hypoxemic Respiratory Failure Is Associated with Lower ICU Survival: The ICEBERG Study. Am J Respir Crit Care Med. Published online June 20, 2025. doi:10.1164/rccm.202411-2146OC2). Therefore, clinicians should systematically monitor ∆P_STAT at the bedside to verify safe spontaneous breathing and prevent patient self-inflicted lung injury. ∆P_STAT represents the change in elastic pressure applied to the respiratory system during the breath and is calculated as the plateau pressure (P_PLAT) minus PEEP.

How to obtain plateau pressure

An end-inspiratory occlusion is used to measure P_PLAT in assisted breaths (Foti G, Cereda M, Banfi G, Pelosi P, Fumagalli R, Pesenti A. End-inspiratory airway occlusion: a method to assess the pressure developed by inspiratory muscles in patients with acute lung injury undergoing pressure support. Am J Respir Crit Care Med. 1997;156(4 Pt 1):1210-1216. doi:10.1164/ajrccm.156.4.96-020313), provided that a plateau of airway pressure is visible. In the case of assisted breaths, the end-inspiratory hold results in an increase of airway pressure above the peak pressure, which is followed by a plateau (Bellani G, Grassi A, Sosio S, Foti G. Plateau and driving pressure in the presence of spontaneous breathing. Intensive Care Med. 2019;45(1):97-98. doi:10.1007/s00134-018-5311-94). The rise in airway pressure up to P_PLAT corresponds with the inspiratory effort of the patient during the breath and is called the Pmus, index (PMI) (Foti G, Cereda M, Banfi G, Pelosi P, Fumagalli R, Pesenti A. End-inspiratory airway occlusion: a method to assess the pressure developed by inspiratory muscles in patients with acute lung injury undergoing pressure support. Am J Respir Crit Care Med. 1997;156(4 Pt 1):1210-1216. doi:10.1164/ajrccm.156.4.96-020313). A readable plateau pressure should be preceded by a steep ramp at the beginning of the hold, rapidly followed by a flat part (Figure 1) (Bianchi I, Grassi A, Pham T, et al. Reliability of plateau pressure during patient-triggered assisted ventilation. Analysis of a multicentre database. J Crit Care. 2022;68:96-103. doi:10.1016/j.jcrc.2021.12.0025). Observational studies report that P_PLAT is readable in more than 90% of the holds (Bellani G, Grassi A, Sosio S, et al. Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome. Anesthesiology. 2019;131(3):594-604. doi:10.1097/ALN.00000000000028461, Bianchi I, Grassi A, Pham T, et al. Reliability of plateau pressure during patient-triggered assisted ventilation. Analysis of a multicentre database. J Crit Care. 2022;68:96-103. doi:10.1016/j.jcrc.2021.12.0025). Holds are unreadable when a plateau can‘t be determined visually, or where inspiratory or expiratory muscle activity occurs during the hold (Figure 2) (Bellani G, Grassi A, Sosio S, et al. Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome. Anesthesiology. 2019;131(3):594-604. doi:10.1097/ALN.00000000000028461).

Screenshot showing pressure and flow waveforms with visible plateau on flow waveform — Figure 1: A visible plateau is identified with PPLAT at 17 cmH2O. In this patient, PPEAK is 12 cmH2O and PEEP is 7 cmH2O. Therefore, ∆PSTAT is 10 cmH2O and PMI is 5 cmH2O.

Screenshot showing non-readable plateau pressure — Figure 2a: Non-readable plateau pressure due to inspiratory muscle activity

Screenshot showing non-readable plateau pressure due to expiratory muscle activity — Figure 2b: Non-readable plateau pressure due to expiratory muscle activity

Screenshot showing non-readable plateau pressure due to inspiratory and expiratory muscle activity — Figure 2c: Non-readable plateau pressure due to a combination of both

Beware of overestimation

Even when a clear plateau is visible, expiratory muscle activity is frequently present (Soundoulounaki S, Akoumianaki E, Kondili E, et al. Airway pressure morphology and respiratory muscle activity during end-inspiratory occlusions in pressure support ventilation. Crit Care. 2020;24(1):467. Published 2020 Jul 28. doi:10.1186/s13054-020-03169-x6), which means that ∆P_STAT may be overestimated in assisted breaths. Therefore, a low ∆P_STAT can be considered as safe.

Note

Bibliografia

1. Bellani G, Grassi A, Sosio S, et al. Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome. Anesthesiology. 2019;131(3):594-604. doi:10.1097/ALN.0000000000002846
2. Grassi A, Bianchi I, Teggia Droghi M, et al. Increased Driving Pressure During Assisted Ventilation for Hypoxemic Respiratory Failure Is Associated with Lower ICU Survival: The ICEBERG Study. Am J Respir Crit Care Med. Published online June 20, 2025. doi:10.1164/rccm.202411-2146OC
3. Foti G, Cereda M, Banfi G, Pelosi P, Fumagalli R, Pesenti A. End-inspiratory airway occlusion: a method to assess the pressure developed by inspiratory muscles in patients with acute lung injury undergoing pressure support. Am J Respir Crit Care Med. 1997;156(4 Pt 1):1210-1216. doi:10.1164/ajrccm.156.4.96-02031
4. Bellani G, Grassi A, Sosio S, Foti G. Plateau and driving pressure in the presence of spontaneous breathing. Intensive Care Med. 2019;45(1):97-98. doi:10.1007/s00134-018-5311-9
5. Bianchi I, Grassi A, Pham T, et al. Reliability of plateau pressure during patient-triggered assisted ventilation. Analysis of a multicentre database. J Crit Care. 2022;68:96-103. doi:10.1016/j.jcrc.2021.12.002
6. Soundoulounaki S, Akoumianaki E, Kondili E, et al. Airway pressure morphology and respiratory muscle activity during end-inspiratory occlusions in pressure support ventilation. Crit Care. 2020;24(1):467. Published 2020 Jul 28. doi:10.1186/s13054-020-03169-x

Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome.

Bellani G, Grassi A, Sosio S, et al. Driving Pressure Is Associated with Outcome during Assisted Ventilation in Acute Respiratory Distress Syndrome. Anesthesiology. 2019;131(3):594-604. doi:10.1097/ALN.0000000000002846

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WHAT WE ALREADY KNOW ABOUT THIS TOPIC Higher driving pressure during controlled mechanical ventilation is known to be associated with increased mortality in patients with acute respiratory distress syndrome.Whereas patients with acute respiratory distress syndrome are initially managed with controlled mechanical ventilation, as they improve, they are transitioned to assisted ventilation. Whether higher driving pressure assessed during pressure support (assisted) ventilation can be reliably assessed and whether higher driving pressure is associated with worse outcomes in patients with acute respiratory distress syndrome has not been well studied. WHAT THIS ARTICLE TELLS US THAT IS NEW This study shows that in the majority of adult patients with acute respiratory distress syndrome, both driving pressure and respiratory system compliance can be reliably measured during pressure support (assisted) ventilation.Higher driving pressure measured during pressure support (assisted) ventilation significantly associates with increased intensive care unit mortality, whereas peak inspiratory pressure does not.Lower respiratory system compliance also significantly associates with increased intensive care unit mortality. BACKGROUND Driving pressure, the difference between plateau pressure and positive end-expiratory pressure (PEEP), is closely associated with increased mortality in patients with acute respiratory distress syndrome (ARDS). Although this relationship has been demonstrated during controlled mechanical ventilation, plateau pressure is often not measured during spontaneous breathing because of concerns about validity. The objective of the present study is to verify whether driving pressure and respiratory system compliance are independently associated with increased mortality during assisted ventilation (i.e., pressure support ventilation). METHODS This is a retrospective cohort study conducted on 154 patients with ARDS in whom plateau pressure during the first three days of assisted ventilation was available. Associations between driving pressure, respiratory system compliance, and survival were assessed by univariable and multivariable analysis. In patients who underwent a computed tomography scan (n = 23) during the stage of assisted ventilation, the quantity of aerated lung was compared with respiratory system compliance measured on the same date. RESULTS In contrast to controlled mechanical ventilation, plateau pressure during assisted ventilation was higher than the sum of PEEP and pressure support (peak pressure). Driving pressure was higher (11 [9-14] vs. 10 [8-11] cm H2O; P = 0.004); compliance was lower (40 [30-50] vs. 51 [42-61] ml · cm H2O; P < 0.001); and peak pressure was similar, in nonsurvivors versus survivors. Lower respiratory system compliance (odds ratio, 0.92 [0.88-0.96]) and higher driving pressure (odds ratio, 1.34 [1.12-1.61]) were each independently associated with increased risk of death. Respiratory system compliance was correlated with the aerated lung volume (n = 23, r = 0.69, P < 0.0001). CONCLUSIONS In patients with ARDS, plateau pressure, driving pressure, and respiratory system compliance can be measured during assisted ventilation, and both higher driving pressure and lower compliance are associated with increased mortality.

Increased Driving Pressure During Assisted Ventilation for Hypoxemic Respiratory Failure Is Associated with Lower ICU Survival: The ICEBERG Study.

Grassi A, Bianchi I, Teggia Droghi M, et al. Increased Driving Pressure During Assisted Ventilation for Hypoxemic Respiratory Failure Is Associated with Lower ICU Survival: The ICEBERG Study. Am J Respir Crit Care Med. Published online June 20, 2025. doi:10.1164/rccm.202411-2146OC

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RATIONALE Driving pressure is marker of severity and a possible target for lung protection during controlled ventilation, but its value during assisted ventilation is unknown. Inspiratory holds provide an estimate of driving pressure (quasi-static). Expiratory holds provide an estimate of the inspiratory effort, useful to estimate the transpulmonary dynamic driving pressure. OBJECTIVES To assess the correlation between driving pressures measured during assisted ventilation and ICU outcomes. METHODS Multicenter prospective observational study. Patients with acute hypoxemic respiratory failure were enrolled within 48 hours of triggering the ventilator. Respiratory mechanics were measured daily and the variables of interest averaged over the first three days of partial assistance. ICU outcomes were collected until day 90. MEASUREMENTS AND MAIN RESULTS Two-hundred ninety-eight patients from 16 centers were enrolled. Tidal volume, peak airway pressure, positive-end-expiratory-pressure and inspiratory effort during the first three days of assisted ventilation did not differ between survivors and non-survivors. Quasi-static driving pressure and transpulmonary dynamic driving pressure were higher in non-survivors than in survivors (13 [11,14] vs 11 [9,13] cmH2O, p<0.001 and 19 [16,23] vs 16 [13,18] cmH2O, p<0.001, respectively), while compliance normalized to predicted body weight was lower (0.65 [0.54,0.84] vs 0.79 [0.64,0.97] ml/cmH2O/kg, p<0.001). Multivariable analysis confirmed the association with outcome. Over study days, static driving pressure significantly diverged between survivors and non-survivors. CONCLUSIONS During assisted ventilation driving pressure and normalized compliance are associated with ICU outcome, despite some overlap. Albeit our study does not allow to estimate if driving pressure is a marker of severity, or a cause of lung injury, it highlights the potential value of monitoring and targeting it during spontaneous assisted breathing.

End-inspiratory airway occlusion: a method to assess the pressure developed by inspiratory muscles in patients with acute lung injury undergoing pressure support.

Foti G, Cereda M, Banfi G, Pelosi P, Fumagalli R, Pesenti A. End-inspiratory airway occlusion: a method to assess the pressure developed by inspiratory muscles in patients with acute lung injury undergoing pressure support. Am J Respir Crit Care Med. 1997;156(4 Pt 1):1210-1216. doi:10.1164/ajrccm.156.4.96-02031

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We evaluated the end-inspiratory occlusion maneuver as a means to estimate the inspiratory effort during pressure support ventilation (PS). In nine nonobstructed acute lung injury (ALI) patients, we applied four levels of PS (0, 5, 10, 15 cm H2O) to modify the inspiratory effort. End inspiratory occlusions (2 to 3 s) were performed at the end of each experimental period by pushing the inspiratory hold button of the ventilator (Servo 900 C; Siemens, Berlin, Germany). We took the difference between the end-inspiratory occlusion plateau pressure and the airway pressure before the occlusion (PEEP + PS) as an estimate of the inspiratory effort and called it PMI (Pmusc,index). From the esophageal pressure tracing we obtained a reference measurement of the pressure developed by the inspiratory muscles at end inspiration (Pmusc,ei) and of the pressure-time product per breath (PTP/b) and per minute (PTP/min). In each patient, PMI was correlated with Pmusc,ei (p < 0.01) and PTP/b (p < 0.01). A PMI threshold of 6 cm H2O detected PTP/min < 125 cm H2O s/min with a sensitivity of 0.89 and a specificity of 0.89. We conclude that PMI is a good estimate of the pressure developed by the inspiratory muscles in ALI patients and may be used to titrate PS level. The major advantage of PMI is that it can be obtained from the ventilator display without any additional equipment.

Plateau and driving pressure in the presence of spontaneous breathing.

Bellani G, Grassi A, Sosio S, Foti G. Plateau and driving pressure in the presence of spontaneous breathing. Intensive Care Med. 2019;45(1):97-98. doi:10.1007/s00134-018-5311-9

Link to publication

Reliability of plateau pressure during patient-triggered assisted ventilation. Analysis of a multicentre database.

Bianchi I, Grassi A, Pham T, et al. Reliability of plateau pressure during patient-triggered assisted ventilation. Analysis of a multicentre database. J Crit Care. 2022;68:96-103. doi:10.1016/j.jcrc.2021.12.002

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PURPOSE An inspiratory hold during patient-triggered assisted ventilation potentially allows to measure driving pressure and inspiratory effort. However, muscular activity can make this measurement unreliable. We aim to define the criteria for inspiratory holds reliability during patient-triggered breaths. MATERIAL AND METHODS Flow, airway and esophageal pressure recordings during patient-triggered breaths from a multicentre observational study (BEARDS, NCT03447288) were evaluated by six independent raters, to determine plateau pressure readability. Features of "readable" and "unreadable" holds were compared. Muscle pressure estimate from the hold was validated against other measures of inspiratory effort. RESULTS Ninety-two percent of the recordings were consistently judged as readable or unreadable by at least four raters. Plateau measurement showed a high consistency among raters. A short time from airway peak to plateau pressure and a stable and longer plateau characterized readable holds. Unreadable plateaus were associated with higher indexes of inspiratory effort. Muscular pressure computed from the hold showed a strong correlation with independent indexes of inspiratory effort. CONCLUSION The definition of objective parameters of plateau reliability during assisted-breath provides the clinician with a tool to target a safer assisted-ventilation and to detect the presence of high inspiratory effort.

Airway pressure morphology and respiratory muscle activity during end-inspiratory occlusions in pressure support ventilation.

Soundoulounaki S, Akoumianaki E, Kondili E, et al. Airway pressure morphology and respiratory muscle activity during end-inspiratory occlusions in pressure support ventilation. Crit Care. 2020;24(1):467. Published 2020 Jul 28. doi:10.1186/s13054-020-03169-x

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BACKGROUND The driving pressure of the respiratory system is a valuable indicator of global lung stress during passive mechanical ventilation. Monitoring lung stress in assisted ventilation is indispensable, but achieving passive conditions in spontaneously breathing patients to measure driving pressure is challenging. The accuracy of the morphology of airway pressure (Paw) during end-inspiratory occlusion to assure passive conditions during pressure support ventilation has not been examined. METHODS Retrospective analysis of end-inspiratory occlusions obtained from critically ill patients during pressure support ventilation. Flow, airway, esophageal, gastric, and transdiaphragmatic pressures were analyzed. The rise of gastric pressure during occlusion with a constant/decreasing transdiaphragmatic pressure was used to identify and quantify the expiratory muscle activity. The Paw during occlusion was classified in three patterns, based on the differences at three pre-defined points after occlusion (0.3, 1, and 2 s): a "passive-like" decrease followed by plateau, a pattern with "clear plateau," and an "irregular rise" pattern, which included all cases of late or continuous increase, with or without plateau. RESULTS Data from 40 patients and 227 occlusions were analyzed. Expiratory muscle activity during occlusion was identified in 79% of occlusions, and at all levels of assist. After classifying occlusions according to Paw pattern, expiratory muscle activity was identified in 52%, 67%, and 100% of cases of Paw of passive-like, clear plateau, or irregular rise pattern, respectively. The driving pressure was evaluated in the 133 occlusions having a passive-like or clear plateau pattern in Paw. An increase in gastric pressure was present in 46%, 62%, and 64% of cases at 0.3, 1, and 2 s, respectively, and it was greater than 2 cmH2O, in 10%, 20%, and 15% of cases at 0.3, 1, and 2 s, respectively. CONCLUSIONS The pattern of Paw during an end-inspiratory occlusion in pressure support cannot assure the absence of expiratory muscle activity and accurate measurement of driving pressure. Yet, because driving pressure can only be overestimated due to expiratory muscle contraction, in everyday practice, a low driving pressure indicates an absence of global lung over-stretch. A measurement of high driving pressure should prompt further diagnostic workup, such as a measurement of esophageal pressure.

Emerging insights into driving pressure

Driving pressure (ΔP), a surrogate marker for lung strain, is increasingly recognized as the ventilatory parameter most strongly associated with outcomes in mechanically ventilated patients.