The case for ECMO
Venovenous extracorporeal membrane oxygenation (VV-ECMO) has become a vital therapeutic option in managing severe acute respiratory distress syndrome (ARDS) when conventional interventions fail. The American Thoracic Society (ATS) [1] in 2024 and the European Society of Intensive Care Medicine (ESICM)[2] in 2023 released updated guidelines addressing the role of VV-ECMO. This article provides an overview of both guidelines, outlining their common ground and key distinctions without evaluating or favoring one approach over another.
ECMO is considered a potentially life-saving intervention in cases of severe ARDS refractory to conventional therapies. However, the decision to initiate ECMO is complex and requires careful consideration of patient selection, timing, and center capabilities.
The American Thoracic Society (ATS), European Society of Intensive Care Medicine (ESICM), and Society of Critical Care Medicine (SCCM) published joint guidelines on mechanical ventilation in ARDS patients in 2017[3], but stopped short of taking a clear stance for or against ECMO in severe cases.
In subsequent years, both organizations have released updated guidelines reflecting evolving clinical insights. The ESICM’s 2023 update and the ATS’s 2024 revision include more defined recommendations for the use of ECMO, acknowledging its life-saving potential in the management of severe ARDS. While aligned in their recognition of ECMO as a treatment option and emphasis on maintaining high standards of care, the two guidelines diverge in key areas – such as the strength and grading of evidence, patient eligibility criteria, and expectations regarding ECMO center infrastructure.
Their recommendations draw on the CESAR[4] and EOLIA[5] trials and are grounded in the GRADE framework for evidence assessment. A meta-analysis of these trials (n = 429) revealed a statistically significant reduction in 60-day mortality with VV-ECMO compared to conventional ventilation (RR 0.72; 95% CI 0.57–0.91), with consistent protective effects observed at 90 days and in composite endpoints like mortality and treatment failure.[6]
ATS Guideline
The ATS conditionally recommends the use of VV-ECMO in selected patients with severe ARDS, based on low certainty of evidence. This cautious stance reflects limitations in the underlying studies and concerns about generalizability beyond expert centers.
Inclusion criteria:
- Reversible etiology of respiratory failure
- Severe hypoxemia (PaO2/FiO2 < 80 mmHg) or hypercapnia (pH < 7.25 with PaCO2 > 60 mmHg)
- Failure of conventional therapies
- Early phase of ARDS (< 7 days)
- Few risk factors for futility
VV-ECMO should be considered only after conventional measures have been fully utilized, including lung-protective ventilation, high PEEP, neuromuscular blockade, and prone positioning. The selection criteria should be carefully considered, focusing on individuals most likely to benefit.
Center requirements:
- High-volume, dedicated ECMO centers are recommended, as volume correlates with outcomes.
- Regional ECMO program organization is encouraged for efficient, safe care delivery.
- Emphasizes variability in center experience and acknowledges health equity concerns in access to ECMO care.
- Notes that access to ECMO-capable centers and appropriate patient selection are not uniform across settings.
ESICM Guideline
In contrast, the ESICM provides a strong recommendation for VV-ECMO in patients with severe ARDS meeting EOLIA trial criteria, based on moderate evidence certainty for non-COVID ARDS. The guideline applies its recommendation to COVID-19 ARDS citing biological plausibility and clinical similarities but with low certainty (due to indirectness).
EOLIA-based inclusion criteria:
- PaO2/FiO2 < 50 mmHg for > 3 hours
- or PaO2/FiO2 < 80 mmHg for > 6 hours
- or pH < 7.25 with PaCO2 ≥ 60 mmHg for > 6 hours
- RR up to 35/min and plateau pressure of ≤ 32 cmH2O
Improved outcomes require ECMO to be delivered as part of a comprehensive care package, including lung-protective ventilation and prone positioning.
Center requirements:
- Defined organizational standards
- Adherence to EOLIA-like protocols
- Case concentration in high-volume centers with multidisciplinary ECMO teams
- Structured training programs aligned with ELSO recommendations, including simulation-based learning
- Development of ECMO networks and mobile ECMO capacity
Shared Principles and Divergent Approaches
Common ground
Both guidelines converge on key principles:
- VV-ECMO is recognized as a valid option in selected cases of severe ARDS.
- It should be performed only in experienced centers with the necessary infrastructure.
- Exhaustion of conventional therapies with less invasive supportive measures (such as lung protective ventilation, prone positioning, PEEP, and potentially neuromuscular blockers) before escalation to VV-ECMO.
- Evidence base relies primarily on CESAR and EOLIA trials.
- Each applies the GRADE framework in evidence assessment.
- Acknowledge the need for further research, especially in long-term outcomes and supportive strategies during VV-ECMO.
Key differences
Although both guidelines followed similar methodology using the same clinical data on the same therapeutic interventions, they diverge in several critical areas. These include the strength of their recommendations, the certainty of the underlying evidence, the specificity of patient selection criteria, and the requirements placed on ECMO centers. This discrepancy has been the focus of several editorials and has been presented and discussed by both sides with their respective reasons.[7][8]
|
Category |
ATS |
ESICM |
|
Strength of recommendation |
Conditional, reflecting caution amid evolving data |
Strong — but specifically for patients fitting strict EOLIA criteria |
|
Evidence certainty |
Rated as low — particularly for COVID-19 ARDS |
Moderate for non-COVID, low for COVID — reflecting global data diversity |
|
Patient selection |
Broad, encouraging multidisciplinary decision-making case-by-case |
Narrow, with firm adherence to EOLIA-based criteria |
|
COVID-19 ARDS guidance |
Not explicitly addressed |
Included as part of a strong recommendation |
|
Emphasis on center standards |
Advocates care in specialized centers with high volume and regional organization |
Mandates defined standards, ECMO networks, and EOLIA-based protocols |
Conclusion
Both guidelines acknowledge ECMO as a potential therapeutic option for severe ARDS, though they differ in their respective criteria and recommendations for implementation. Collectively, this marks a historic milestone in the pursuit of evidence-based treatment for one of the most formidable challenges in critical care. The technological, clinical, and academic contributions recognized by both societies underscore a shared commitment to advancing this field and fostering future innovation.
This overview is intended solely as a neutral summary of published clinical guidelines and does not represent an interpretation or position by Getinge. Readers are encouraged to consult the original sources for complete clinical context.