Variables: 0 1 2 3 4 PaO2/FIO2 (on 100% O2 for >20 minutes) ≥300 225-299 175-224 100-174 <100 PEEP ≤5 6-8 9-11 12-14 ≥15 CXR (# of quadrants infiltrated) 0 (normal) 1 2 3 4 Compliance (ml/cmH2O)* ≥80 60-79 40-59 20-39 ≤19

*The compliance may be calculated as follows: TV /(PIP-PEEP) The Murray score is calculated by taking the score for each variable and an average score >3 can be an indication for VV-ECMO Adapted from Murray JF, Matthay MA, Luce JM, Flick MR. An expanded definition of the adult respiratory distress syndrome. Am Rev Respir Dis. 1988 Sep;138(3):720-3.

Table 2: Indications for ECMO: Respiratory Failure (Murray Score).