The medical management of acute respiratory distress syndrome

Intensive Care Medicine | Published: 22 December 2025

Abstract

Despite advancements in bedside monitoring and paradigm shifts in standard ventilatory practice, mortality from acute respiratory distress syndrome (ARDS) remains high. The recent Global ARDS definition adopts a more pragmatic approach enabling earlier identification across a broader patient spectrum, independent of the interventions being administered. Meanwhile, our understanding of managing this heterogeneous syndrome has shifted towards defining precise subgroups with shared therapeutic targets. Physiological, biological, and radiological phenotypes may modify the response to interventions previously showing indeterminate benefit, making them potentially central to future personalised ARDS management. This narrative review summarises core evidence for the medical and ventilatory management of ARDS, explores emerging concepts, and offers clinicians a framework for current best practice and a roadmap for possible future directions.

 

Toward optimal mechanical ventilation of the injured lung: the role of expiratory duration

Critical Care volume 29, Article number: 481 (2025) Published: 10 November 2025

Abstract

Positive pressure mechanical ventilation is a life-saving intervention for patients with acute respiratory distress syndrome (ARDS), but it can also increase mortality by causing ventilator-induced lung injury (VILI) if applied inappropriately. Although strategies like low-tidal volume ventilation and prone positioning have been shown to reduce mortality, the optimal patient-specific approach to mechanical ventilation in ARDS has yet to be identified. The worst manifestations of acute lung injury arise when fluid and proteins from the blood leak through a damaged blood-gas barrier, accumulating in the airspaces and impairing the ability of pulmonary surfactant to lower surface tension. This amplifies the ventilatory stresses in the lung tissues, which further damages the blood-gas barrier, leading to a vicious cycle of worsening injury. Studies suggest that VILI may be most effectively avoided by preventing the atelectrauma caused during inspiration by the forced reopening of lung units that close during each expiration. Atelectrauma is conventionally mitigated with positive end-expiratory pressure (PEEP), but it remains unclear if the algorithmic selection of PEEP leads to mortality reductions in ARDS. Animal studies, however, support the efficacy of exploiting the time-dependent nature of recruitment and derecruitment, for example through the use of brief expiratory durations that continually adapt to changing lung mechanics. Despite decades of research, it remains unclear how to minimize VILI in any given ARDS patient. Animal studies coupled with energy dissipation analysis indicate that the prevention of VILI requires, above all, avoidance of the atelectrauma caused by cyclic recruitment and derecruitment in the lung. In addition, the path to optimal mechanical ventilation in ARDS must be based not only on the amplitudes of the pressures applied to the lung but also on their temporal natures.

 

Comparison of two transpulmonary pressure-based positive end-expiratory pressure titration strategies in acute respiratory distress syndrome: a randomized crossover study

Critical Care volume 29, Article number: 409 (2025) Published: 29 September 2025

Background

Esophageal pressure monitoring, which enables the estimation of transpulmonary pressure, has been proposed to personalize ventilator settings, particularly positive end-expiratory pressure (PEEP), in patients with acute respiratory distress syndrome (ARDS). Two conceptually different transpulmonary pressure-based PEEP titration strategies have thus been described but have never been compared. This study aims to compare the PEEP levels obtained with these two distinct strategies and their physiological effects.

Methods

This was a randomized crossover physiological study. Twenty patients with moderate to severe ARDS (PaO2/FiO2 < 150 mmHg) were included in an academic intensive care unit. The two transpulmonary pressure-based PEEP titration strategies were applied for 45 min each in a randomized order, separated by a 45-minute washout period. In the directly measured expiratory transpulmonary pressure (PL, exp) strategy, PEEP was set to target a PL, exp using a PL, exp/FiO2 table. In the calculated inspiratory transpulmonary pressure (PL, insp) strategy, PEEP was set to maintain PL, insp estimated using the lung/respiratory system elastance ratio between 20 and 22 cmH2O. Gas exchange, hemodynamics and partitioned respiratory mechanics were assessed at the end of each PEEP application period.

Results

Median PEEP levels determined by the two strategies were not different; however, individual values were uncorrelated, with a difference of at least 3 cmH2O in 14 (70%) patients. The PL, insp strategy resulted in higher PEEP levels than the PL, exp strategy in the non-obese patients but not in the obese patients. The effects on gas exchange, hemodynamics, and respiratory mechanics did not differ between the two strategies considering the entire study population or the obese and non-obese patients separately. Recruitment with PEEP (assessed by the recruited lung volume from PEEP 5 cmH2O), PL, insp, transpulmonary driving pressure and lung strain did not differ between the two strategies.

Conclusions

The two transpulmonary pressure-based titration strategies result in different PEEP levels in most patients. Neither strategy is associated with higher recruited lung volume or lower estimated Stress and Strain.

 

 

Electrical Impedance Tomography in Acute Respiratory Distress Syndrome Management

 

by Jimenez, Jose Victor; Weirauch, Andrew J.; Culter, Christopher A.; Choi, Philip J.; Hyzy, Robert C.

 

Critical Care Medicine: August 2022 - Volume 50 - Issue 8 - p 1210-1223

 

OBJECTIVE: To describe, through a narrative review, the physiologic principles underlying electrical impedance tomography, and its potential applications in managing 

acute respiratory distress syndrome (ARDS). To address the current evidence supporting its use in different clinical scenarios along the ARDS management continuum.

DATA SOURCES: We performed an online search in Pubmed to review articles. We searched MEDLINE, Cochrane Central Register, and clinicaltrials.gov for controlled trials databases.

STUDY SELECTION: Selected publications included case series, pilot-physiologic studies, observational cohorts, and randomized controlled trials. To describe the rationale underlying physiologic principles, we included experimental studies.

DATA EXTRACTION: Data from relevant publications were reviewed, analyzed, and its content summarized.

DATA SYNTHESIS: Electrical impedance tomography is an imaging technique that has aided in understanding the mechanisms underlying multiple interventions used in ARDS management. It has the potential to monitor and predict the response to prone positioning, aid in the dosage of flow rate in high-flow nasal cannula, and guide the titration of positive-end expiratory pressure during invasive mechanical ventilation. The latter has been demonstrated to improve physiologic and mechanical parameters correlating with lung recruitment. Similarly, its use in detecting pneumothorax and harmful patient-ventilator interactions such as pendelluft has been proven effective. Nonetheless, its impact on clinically meaningful outcomes remains to be determined.

CONCLUSIONS: Electrical impedance tomography is a potential tool for the individualized management of ARDS throughout its different stages. Clinical trials should aim to determine whether a specific approach can improve clinical outcomes in ARDS management.

 

 

 

Oxygenation versus driving pressure for determining the best positive end-expiratory pressure in acute respiratory distress syndrome

 

by Saida Rezaiguia-Delclaux, Léo Ren, Aurélie Gruner, Calypso Roman, Thibaut Genty and François Stéphan 

 

Critical Care volume 26, Article number: 214 (2022)  Published: 13 July 2022

 

Objective

The aim of this prospective longitudinal study was to compare driving pressure and absolute PaO2/FiO2 ratio in determining the best positive end-expiratory pressure (PEEP) level.

Patients and methods

In 122 patients with acute respiratory distress syndrome, PEEP was increased until plateau pressure reached 30 cmH2O at constant tidal volume, then decreased at 15-min intervals, to 15, 10, and 5 cmH2O. The best PEEP by PaO2/FiO2 ratio (PEEPO2) was defined as the highest PaO2/FiO2 ratio obtained, and the best PEEP by driving pressure (PEEPDP) as the lowest driving pressure. The difference between the best PEEP levels was compared to a non-inferiority margin of 1.5 cmH2O.

Main results

The best mean PEEPO2 value was 11.9 ± 4.7 cmH2O compared to 10.6 ± 4.1 cmH2O for the best PEEPDP: mean difference = 1.3 cmH2O (95% confidence interval [95% CI], 0.4–2.3; one-tailed P value, 0.36). Only 46 PEEP levels were the same with the two methods (37.7%; 95% CI 29.6–46.5). PEEP level was ≥ 15 cmH2O in 61 (50%) patients with PEEPO2 and 39 (32%) patients with PEEPDP (P = 0.001).

Conclusion

Depending on the method chosen, the best PEEP level varies. The best PEEPDP level is lower than the best PEEPO2 level. Computing driving pressure is simple, faster and less invasive than measuring PaO2. However, our results do not demonstrate that one method deserves preference over the other in terms of patient outcome.

 

Personalized Positive End-Expiratory Pressure in Acute Respiratory Distress Syndrome: Comparison Between Optimal Distribution of Regional Ventilation and Positive Transpulmonary Pressure

 

Personalized Positive End-Expiratory Pressure in Acute Respiratory Distress Syndrome: Comparison Between Optimal Distribution of Regional Ventilation and Positive Transpulmonary Pressure

by Scaramuzzo, Gaetano; Spadaro, Savino; Dalla Corte, Francesca; Waldmann, Andreas D.; Böhm, Stephan H.; Ragazzi, Riccardo; Marangoni, Elisabetta; Grasselli, Giacomo; Pesenti, Antonio; Volta, Carlo Alberto; Mauri, Tommaso

Critical Care Medicine: August 2020 - Volume 48 - Issue 8 - p 1148-1156

Objectives:

Different techniques exist to select personalized positive end-expiratory pressure in patients affected by the acute respiratory distress syndrome. The positive end-expiratory transpulmonary pressure strategy aims to counteract dorsal lung collapse, whereas electrical impedance tomography could guide positive end-expiratory pressure selection based on optimal homogeneity of ventilation distribution. We compared the physiologic effects of positive end-expiratory pressure guided by electrical impedance tomography versus transpulmonary pressure in patients affected by acute respiratory distress syndrome.

Design: Cross-over prospective physiologic study.

Setting: Two academic ICUs.

Patients: Twenty ICU patients affected by acute respiratory distress syndrome undergoing mechanical ventilation.

 Intervention: Patients monitored by an esophageal catheter and a 32-electrode electrical impedance tomography monitor underwent two positive end-expiratory pressure titration trials by randomized cross-over design to find the level of positive end-expiratory pressure associated with: 1) positive end-expiratory transpulmonary pressure (PEEPPL) and 2) proportion of poorly or nonventilated lung units (Silent Spaces) less than or equal to 15% (PEEPEIT). Each positive end-expiratory pressure level was maintained for 20 minutes, and afterward, lung mechanics, gas exchange, and electrical impedance tomography data were collected. Measurements and Main Results: PEEPEIT and PEEPPL differed in all patients, and there was no correlation between the levels identified by the two methods (Rs = 0.25; p = 0.29). PEEPEIT determined a more homogeneous distribution of ventilation with a lower percentage of dependent Silent Spaces (p = 0.02), whereas PEEPPL was characterized by lower airway—but not transpulmonary—driving pressure (p = 0.04). PEEPEIT was significantly higher than PEEPPL in subjects with extrapulmonary acute respiratory distress syndrome (p = 0.006), whereas the opposite was true for pulmonary acute respiratory distress syndrome (p = 0.03).

Conclusions: Personalized positive end-expiratory pressure levels selected by electrical impedance tomography– and transpulmonary pressure–based methods are not correlated at the individual patient level. PEEPPL is associated with lower dynamic stress, whereas PEEPEIT may help to optimize lung recruitment and homogeneity of ventilation. The underlying etiology of acute respiratory distress syndrome could deeply influence results from each method.

Letter: Advanced respiratory monitoring in COVID-19 patients: use less PEEP!

Letter: Advanced respiratory monitoring in COVID-19 patients: use less PEEP!

by Lisanne Roesthuis, Maarten van den Berg and Hans van der Hoeven

Critical Care volume 24, Article number: 230 (2020) Published: 15 May 2020

In the majority of coronavirus disease 2019 (COVID-19) patients, respiratory mechanics is different from the “normal” acute respiratory distress syndrome (ARDS) patient. Plateau pressures and driving pressures are often low and respiratory system compliance relatively normal compared to the ARDS patient [1]. Many physicians use high positive end-expiratory pressure (PEEP) for patients with COVID-19 although the potential for recruitment is often low [1, 2]. We fear that the high compliance of the respiratory system in combination with high PEEP will lead to hyperinflation, high dead space, and potentially right ventricular failure.

We have used the following strategy for COVID-19 patients (N = 70): after intubation, immediately prone positioning for at least 3 days, using the lowest possible PEEP to obtain adequate oxygenation with FiO2 of 50%. We assessed the effects of different PEEP levels on respiratory mechanics and ventilation-perfusion mismatching.