Extracorpreal membrane oxygenation is a temporizing mechanical support to heart or lung function in the setting of cardiopulmonary failure. In the setting of severe respiratory failure, patients that may benefit from and/or have an indication for ECMO are described in the Extracorporeal Life Support Organization Respiratory Failure Supplement to ESLO General Guideline, December 2013:

Indications:

• In hypoxic respiratory failure due to any cause (primary or secondary) ECLS should be considered when the risk of mortality is 50% or greater, and is indicated when the risk of mortality is 80% or greater. 

1. 50% mortality risk is associated with a PaO2/FiO2 < 150 on FiO2 > 90% and/or Murray score 2-3. Murray Score Calculator
2. 80% mortality risk is associated with a PaO2/FiO2 < 100 on FiO2> 90% and/or Murray score 3-4 despite optimal care for 6 hours or more. 

• CO2 retention on mechanical ventilation despite high Pplat (>30 cm H2O) 
• Severe air leak syndromes 
• Need for intubation in a patient on lung transplant list 
• Immediate cardiac or respiratory collapse (PE, blocked airway, unresponsive to optimal care)

Contraindications:
There are no absolute contraindications to ECLS, as each patient is considered individually with respect to risks and benefits. There are conditions, however, that are associated with a poor outcome despite ECLS, and can be considered relative contraindications.

• Mechanical ventilation at high settings (FiO2 > .9, P-plat > 30) for7 days or more 
• Major pharmacologic immunosuppression (absolute neutrophil count <400/mm3) 
• CNS hemorrhage that is recent or expanding 
• Non recoverable comorbidity such as major CNS damage or terminal malignancy 
• Age: no specific age contraindication but consider increasing risk with increasing age
  

Additional Links:
Extracorporeal Life Support Organization Guidelines
NHLBI ARDS Network Ventilator Protocol
ECMO Review of Lifesaving Technology, Journal of Thoracic Disease, July 2015

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