60 years of ARDS and the evolution of extracorporeal lung support – from ECMO to ECCO2R

 

Intensive Care Medicine  Published: 07 July 2026

 

Abstract

Extracorporeal life support (ECLS), including venovenous extracorporeal membrane oxygenation (VV-ECMO) and extracorporeal carbon dioxide removal (ECCO₂R), is an established treatment for selected patients with acute respiratory distress syndrome (ARDS). In this review, on the 60th anniversary of ARDS, we review the evolution of ECLS as a support strategy in ARDS, the evidence surrounding its efficacy, factors associated with prognosis, management of patients on ECLS, associated complications, and long-term outcomes among survivors. We also highlight existing areas of uncertainty, and ongoing clinical research that will define the next decade and beyond of ECLS for ARDS.

 

 

Can we predict the future of respiratory failure prediction?

Critical Care volume 29, Article number: 253 (2025)

Background

Mortality in patients with acute respiratory failure remains high. Predicting progression of acute respiratory failure may be critical to improving patient outcomes. Machine learning, a subset of artificial intelligence is a rapidly expanding area, which is being integrated into several areas of clinical medicine. This manuscript will address the knowledge gap in predicting the onset and progression of respiratory failure, provide a review of existing prognostic strategies, and provide a clinical perspective on the implementation and future integration of machine learning into clinical care.

Main body

Existing strategies for predicting respiratory failure, such as prediction scores and biomarkers, offer both strengths and limitations. While these tools provide some prognostic value, machine learning presents a promising, data-driven approach to prognostication in the intensive care unit. Machine learning has already shown success in various areas of clinical medicine, although relatively few algorithms target respiratory failure prediction specifically. As machine learning grows in the context of respiratory failure, outcomes such as the need for invasive mechanical ventilation and escalation of respiratory support (e.g. non-invasive ventilation) have been identified as key targets. However, the development and implementation of machine learning models in clinical care involves complex challenges. Future success will depend on rigorous model validation, clinician collaboration, thoughtful trial design, and the application of implementation science to ensure integration into clinical care.

Conclusion

Machine learning holds promise for optimizing treatment strategies and potentially improving outcomes in respiratory failure. However, further research and development are necessary to fully realize its potential in clinical practice.

 

Advanced waveform analysis of diaphragm surface EMG allows for continuous non-invasive assessment of respiratory effort in critically ill patients at different PEEP levels

 

by R. S. P. Warnaar, A. D. Cornet, A. Beishuizen, C. M. Moore, D. W. Donker and E. Oppersma 

 

Critical Care volume 28, Article number: 195, Published: 09 June 2024

 

Background

Respiratory effort should be closely monitored in mechanically ventilated ICU patients to avoid both overassistance and underassistance. Surface electromyography of the diaphragm (sEMGdi) offers a continuous and non-invasive modality to assess respiratory effort based on neuromuscular coupling (NMCdi). The sEMGdi derived electrical activity of the diaphragm (sEAdi) is prone to distortion by crosstalk from other muscles including the heart, hindering its widespread use in clinical practice. We developed an advanced analysis as well as quality criteria for sEAdi waveforms and investigated the effects of clinically relevant levels of PEEP on non-invasive NMCdi.

Methods

NMCdi was derived by dividing end-expiratory occlusion pressure (Pocc) by sEAdi, based on three consecutive Pocc manoeuvres at four incremental (+ 2 cmH2O/step) PEEP levels in stable ICU patients on pressure support ventilation. Pocc and sEAdi quality was assessed by applying a novel, automated advanced signal analysis, based on tolerant and strict cut-off criteria, and excluding inadequate waveforms. The coefficient of variations (CoV) of NMCdi after basic manual and automated advanced quality assessment were evaluated, as well as the effect of an incremental PEEP trial on NMCdi.

Results

593 manoeuvres were obtained from 42 PEEP trials in 17 ICU patients. Waveform exclusion was primarily based on low sEAdi signal-to-noise ratio (Ntolerant = 155, 37%, Nstrict = 241, 51% waveforms excluded), irregular or abrupt cessation of Pocc (Ntolerant = 145, 35%, Nstrict = 145, 31%), and high sEAdi area under the baseline (Ntolerant = 94, 23%, Nstrict = 79, 17%). Strict automated assessment allowed to reduce CoV of NMCdi to 15% from 37% for basic quality assessment. As PEEP was increased, NMCdi decreased significantly by 4.9 percentage point per cmH2O.

Conclusion

Advanced signal analysis of both Pocc and sEAdi greatly facilitates automated and well-defined identification of high-quality waveforms. In the critically ill, this approach allowed to demonstrate a dynamic NMCdi (Pocc/sEAdi) decrease upon PEEP increments, emphasising that sEAdi-based assessment of respiratory effort should be related to PEEP dependent diaphragm function. This novel, non-invasive methodology forms an important methodological foundation for more robust, continuous, and comprehensive assessment of respiratory effort at the bedside.

 

Outcomes of patients aged ≥80 years with respiratory failure initially treated with non-invasive ventilation in European intensive care units before and during COVID-19 pandemic

 

by Kamil Polok, Jakub Fronczek, Bertrand Guidet, Antonio Artigas, Dylan W. De Lange, Jesper Fjølner, Susannah Leaver, Michael Beil, Sigal Sviri, Raphael Romano Bruno, Bernhard Wernly, Bernardo Bollen Pinto, Joerg C. Schefold, Dorota Studzińska, Michael Joannidis, Sandra Oeyen… 

 

Annals of Intensive Care volume 13, Article number: 82 (2023)

 

Background

Non-invasive ventilation (NIV) has been commonly used to treat acute respiratory failure due to COVID-19. In this study we aimed to compare outcomes of older critically ill patients treated with NIV before and during the COVID-19 pandemic.

Methods

We analysed a merged cohort of older adults admitted to intensive care units (ICUs) due to respiratory failure. Patients were enrolled into one of two prospective observational studies: before COVID-19 (VIP2—2018 to 2019) and admitted due to COVID-19 (COVIP—March 2020 to January 2023). The outcomes included: 30-day mortality, intubation rate and NIV failure (death or intubation within 30 days).

Results

The final cohort included 1986 patients (1292 from VIP2, 694 from COVIP) with a median age of 83 years. NIV was used as a primary mode of respiratory support in 697 participants (35.1%). ICU admission due to COVID-19 was associated with an increased 30-day mortality (65.5% vs. 36.5%, HR 2.18, 95% CI 1.71 to 2.77), more frequent intubation (36.9% vs. 17.5%, OR 2.63, 95% CI 1.74 to 3.99) and NIV failure (76.2% vs. 45.3%, OR 4.21, 95% CI 2.84 to 6.34) compared to non-COVID causes of respiratory failure. Sensitivity analysis after exclusion of patients in whom life supporting treatment limitation was introduced during primary NIV confirmed higher 30-day mortality in patients with COVID-19 (52.5% vs. 23.4%, HR 2.64, 95% CI 1.83 to 3.80).

Conclusion

The outcomes of patients aged ≥80 years treated with NIV during COVID-19 pandemic were worse compared then those treated with NIV in the pre-pandemic era.

Critical Care Bulletin - February 2022

 

Tracheostomy timing and clinical outcomes in ventilated COVID-19 patients: a systematic review and meta-analysis

 

by Yun Ji, Yumin Fang, Baoli Cheng, Libin Li and Xiangming Fang 

 

Critical Care volume 26, Article number: 40 (2022)

 

Background

The association of tracheostomy timing and clinical outcomes in ventilated COVID-19 patients remains controversial. We performed a meta-analysis to evaluate the impact of early tracheostomy compared to late tracheostomy on COVID-19 patients’ outcomes.

Methods

We searched Medline, Embase, Cochrane, and Scopus database, along with medRxiv, bioRxiv, and Research Square, from December 1, 2019, to August 24, 2021. Early tracheostomy was defined as a tracheostomy conducted 14 days or less after initiation of invasive mechanical ventilation (IMV). Late tracheostomy was any time thereafter. Duration of IMV, duration of ICU stay, and overall mortality were the primary outcomes of the meta-analysis. Pooled odds ratios (OR) or the mean differences (MD) with 95%CIs were calculated using a random-effects model.

Results

Fourteen studies with a cumulative 2371 tracheostomized COVID-19 patients were included in this review. Early tracheostomy was associated with significant reductions in duration of IMV (2098 patients; MD − 9.08 days, 95% CI − 10.91 to − 7.26 days, p < 0.01) and duration of ICU stay (1224 patients; MD − 9.41 days, 95% CI − 12.36 to − 6.46 days, p < 0.01). Mortality was reported for 2343 patients and was comparable between groups (OR 1.09, 95% CI 0.79–1.51, p = 0.59).

Conclusions

The results of this meta-analysis suggest that, compared with late tracheostomy, early tracheostomy in COVID-19 patients was associated with shorter duration of IMV and ICU stay without modifying the mortality rate. These findings may have important implications to improve ICU availability during the COVID-19 pandemic.

 

 

 

 

Severe Respiratory Failure, Extracorporeal Membrane Oxygenation, and Intracranial Hemorrhage

Severe Respiratory Failure, Extracorporeal Membrane Oxygenation, and Intracranial Hemorrhage
Lockie, CJ et al
Critical Care Medicine: October 2017 - Volume 45 - Issue 10 - p 1642–1649

Objectives: For patients supported with veno-venous extracorporeal membrane oxygenation, the occurrence of intracranial hemorrhage is associated with a high mortality. It is unclear whether intracranial hemorrhage is a consequence of the extracorporeal intervention or of the underlying severe respiratory pathology. In a cohort of patients transferred to a regional severe respiratory failure center that routinely employs admission brain imaging, we sought 1) the prevalence of intracranial hemorrhage; 2) survival and neurologic outcomes; and 3) factors associated with intracranial hemorrhage. 
Design: A single-center, retrospective, observational cohort study. Setting: Tertiary referral severe respiratory failure center, university teaching hospital. Patients: Patients admitted between December 2011 and February 2016. Intervention: None. Measurements and Main Results: Three hundred forty-two patients were identified: 250 managed with extracorporeal support and 92 managed using conventional ventilation. The prevalence of intracranial hemorrhage was 16.4% in extracorporeal membrane oxygenation patients and 7.6% in conventionally managed patients (p = 0.04). Multivariate analysis revealed factors independently associated with intracranial hemorrhage to be duration of ventilation (d) (odds ratio, 1.13 [95% CI, 1.03–1.23]; p = 0.011) and admission fibrinogen (g/L) (odds ratio, 0.73 [0.57–0.91]; p = 0.009); extracorporeal membrane oxygenation was not an independent risk factor (odds ratio, 3.29 [0.96–15.99]; p = 0.088). In patients who received veno-venous extracorporeal membrane oxygenation, there was no significant difference in 6-month survival between patients with and without intracranial hemorrhage (68.3% vs 76.0%; p = 0.350). Good neurologic function was observed in 92%. Conclusions: We report a higher prevalence of intracranial hemorrhage than has previously been described with high level of neurologically intact survival. Duration of mechanical ventilation and admission fibrinogen, but not exposure to extracorporeal support, are independently associated with intracranial hemorrhage.

A Technique of Awake Bronchoscopic Endotracheal Intubation for Respiratory Failure in Patients With Right Heart Failure and Pulmonary Hypertension

A Technique of Awake Bronchoscopic Endotracheal Intubation for Respiratory Failure in Patients With Right Heart Failure and Pulmonary Hypertension
Johannes, J et al
Critical Care Medicine:  September 2017 - Volume 45 - Issue 9 - p e980–e984

Objective: Patients with pulmonary hypertension and right heart failure have a high risk of clinical deterioration and death during or soon after endotracheal intubation. The effects of sedation, hypoxia, hypoventilation, and changes in intrathoracic pressure can lead to severe hemodynamic instability. In search for safer approach to endotracheal intubation in this cohort of patients, we evaluate the safety and feasibility of an alternative intubation technique. Data Sources: Retrospective data analysis. Study Selection: Two medical ICUs in large university hospitals in the United States. Data Extraction: We report a case series of nine nonconsecutive patients with compromised right heart function, pulmonary hypertension, and severe acute hypoxemic respiratory failure who underwent endotracheal intubation with a novel technique combining awake bronchoscopic intubation supported with nasally delivered noninvasive positive pressure ventilation or high-flow nasal cannula. Data Synthesis: All patients were intubated in the first attempt without major complications and eight patients (88%) were alive 24 hours after intubation. Systemic hypotension was the most frequent complication following the procedure. Conclusions: Awake bronchoscopic intubation supported with a noninvasive positive pressure delivery systems may be feasible alternative to standard direct laryngoscopy approach. Further studies are needed to better assess its safety and applicability.

Nonlinear Imputation of PaO2/FIO2 From SpO2/FIO2 Among Mechanically Ventilated Patients in the ICU: A Prospective, Observational Study

Nonlinear Imputation of PaO2/FIO2 From SpO2/FIO2 Among Mechanically Ventilated Patients in the ICU: A Prospective, Observational Study

Brown, S et al
Critical Care Medicine: August 2017 - Volume 45 - Issue 8 - p 1317–1324

Objectives: In the contemporary ICU, mechanically ventilated patients may not have arterial blood gas measurements available at relevant timepoints. Severity criteria often depend on arterial blood gas results. Retrospective studies suggest that nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 is accurate, but this has not been established prospectively among mechanically ventilated ICU patients. The objective was to validate the superiority of nonlinear imputation of PaO2/FIO2 among mechanically ventilated patients and understand what factors influence the accuracy of imputation. 
Design: Simultaneous SpO2, oximeter characteristics, receipt of vasopressors, and skin pigmentation were recorded at the time of a clinical arterial blood gas. Acute respiratory distress syndrome criteria were recorded. For each imputation method, we calculated both imputation error and the area under the curve for patients meeting criteria for acute respiratory distress syndrome (PaO2/FIO2 ≤ 300) and moderate-severe acute respiratory distress syndrome (PaO2/FIO2 ≤ 150). Setting: Nine hospitals within the Prevention and Early Treatment of Acute Lung Injury network. Patients: We prospectively enrolled 703 mechanically ventilated patients admitted to the emergency departments or ICUs of participating study hospitals. Interventions: None. Measurements and Main Results: We studied 1,034 arterial blood gases from 703 patients; 650 arterial blood gases were associated with SpO2 less than or equal to 96%. Nonlinear imputation had consistently lower error than other techniques. Among all patients, nonlinear had a lower error (p < 0.001) and higher (p < 0.001) area under the curve (0.87; 95% CI, 0.85–0.90) for PaO2/FIO2 less than or equal to 300 than linear/log-linear (0.80; 95% CI, 0.76–0.83) imputation. All imputation methods better identified moderate-severe acute respiratory distress syndrome (PaO2/FIO2 ≤ 150); nonlinear imputation remained superior (p < 0.001). For PaO2/FIO2 less than or equal to 150, the sensitivity and specificity for nonlinear imputation were 0.87 (95% CI, 0.83–0.90) and 0.91 (95% CI, 0.88–0.93), respectively. Skin pigmentation and receipt of vasopressors were not associated with imputation accuracy. 
Conclusions: In mechanically ventilated patients, nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 seems accurate, especially for moderate-severe hypoxemia. Linear and log-linear imputations cannot be recommended.