Murray Score for Acute Lung Injury

According to the Extracorporeal Life Support Organization (ELSO) guidelines:

• Patients with ARDS and a Murray Score of 3-4 may be considered for ECMO cannulation in the correct clinical setting.
• Patients with a Murray Score >2 could be considered for transfer to a center with ECMO capabilities.

It is important to consider all other patient factors as well as contraindications and risks of ECMO. Relative contraindications include:

• Any condition that would limit the benefit of ECMO (such as severe neurologic injury or advanced malignancy).
• Any contraindication to anticoagulation.
• High FiO₂ requirements or high-pressure mechanical ventilation >7 days.
• Limited vascular access.

Once the decision is made to initiate ECMO, the patient should be transferred and managed at a center experienced at treating patients with extracorporeal life support. The following algorithm highlights the basic considerations for types of ECMO cannulation strategies based on the different pathophysiological indications.

Once the patient is supported on extracorporeal life support with direct oxygenation and removal of carbon dioxide from the blood, it may be possible to apply low-volume, low-pressure ventilation strategies, which is the underlying principle for ARDS management.

Adapted from the ELSO Red Book, 5th Edition (Brogan et al).

The Murray Score is only a guide and should not supercede clinical judgement by clinicians about the appropriateness of ECMO initiation.

In the only modern clinical trial evaluating ECMO for ARDS (the CESAR Trial in Lancet 2009), the indications for ECMO in patients with ARDS included Murray Scores 3-4 or a pH <7.20 despite optimal conventional treatment. Patients with Murray Scores >2 and P/F ratio <150 should be considered for transfer to an ECMO center.