Critical Appraisal of the CESAR Trial for ECMO in Severe Respiratory Failure

Introduction to ECMO Therapy

The American Thoracic Society suggests the use of VV-ECMO in selected patients with severe ARDS, but this is a conditional recommendation with low certainty of evidence, specifically citing CESAR's limitations 1, 2, 3, 4

The CESAR trial was not a pure comparison of ECMO versus conventional ventilation, but rather a comparison of transfer to a specialized center versus staying at the original hospital, with significant limitations including lack of standardized ventilator management in the control arm and incomplete application of the intervention 1, 2, 3, 4
The certainty of evidence from the CESAR trial was downgraded from moderate to low for indirectness due to these limitations 1, 2, 3, 4

The American Thoracic Society recommends considering VV-ECMO in patients with reversible etiologies of respiratory failure, very severe hypoxemia or hypercapnia despite optimal conventional management, and early in the ARDS course, with few risk factors for futility of treatment 1, 2, 3
Less invasive therapies, such as lung-protective ventilation, higher PEEP, neuromuscular blockade, and prone positioning, must be optimized before considering VV-ECMO 1, 2, 3, 4

ECMO is resource-intensive and should be provided in high-volume, dedicated centers with regional organization, with mobile ECMO teams and transfer networks established 2, 5
There are disparities in patient selection based on insurance status, income, and gender, and variable access to ECMO centers has serious implications for health equity 1, 2, 3

CESAR supports a conditional recommendation for VV-ECMO in highly selected severe ARDS patients at experienced centers, with exhaustion of conventional therapies first and consideration of transfer to an ECMO-capable center when feasible 1, 2, 3, 4
The certainty of evidence remains low due to CESAR's methodological limitations 1, 2, 3, 4

VV-ECMO should be considered when conventional ventilation strategies fail to maintain acceptable gas exchange in patients with inhalation poisoning, particularly when there is persistent hypoxemia despite optimal mechanical ventilation 6
VV-ECMO is indicated after failure of less invasive rescue therapies such as inhaled nitric oxide/prostacyclin, prone positioning, neuromuscular blockade, and corticosteroids 6

VV-ECMO should be initiated within 7 days of respiratory failure onset for optimal outcomes 7

VV-ECMO should be performed at centers with sufficient experience, volume, and expertise to ensure it is used safely 8
Hospitals without ECMO capability should establish institutional guidelines to identify ECMO-eligible patients and relationships with ECMO-capable institutions for timely transfer 6
A multidisciplinary team including intensivists, pulmonologists, and respiratory therapists should be involved in decision-making, however the American College of Chest Physicians was not mentioned in this context, instead it was mentioned in 9
Continuous monitoring of arterial blood pressure, respiratory parameters, regular arterial blood gas analysis, daily echocardiography, and meticulous tracking of fluid balance are essential 9

ECMO centers caring for more than 20-25 cases per year have significantly better outcomes than centers with lower volumes 10
The learning curve to establish competence requires at least 20 cases for optimal results 10

Additional evidence is necessary to make definitive recommendations for or against the use of ECMO in all cases of severe ARDS, including those from inhalation poisoning 11
The American Thoracic Society recommends ongoing research measuring clinical outcomes among patients with severe ARDS who undergo ECMO 11