STEP 1. ENTER PaO₂/FiO₂ in mmHg on 100% oxygen for at least 20 minutes. ( Multiply the value in kPa with 7.5 to convert into mmHg).

STEP 2. ENTER Number of quadrants with infiltration seen on chest x-ray. (Normal =0, 1 point per quadrant infiltrated).

STEP 3. ENTER PEEP value on the ventilator.

STEP 4. ENTER compliance (ml/cmH₂O) [Compliance may be calculated as: (Tidal Volume) / (PIP-PEEP)].

MURRAY SCORE=