Recent data in a meta-analysis of randomized controlled trials of acute respiratory distress syndrome (ARDS) suggest that driving pressure (ΔP) may be a critical factor in outcome, with a ΔP <14 cmH2O being a better predictor of survival. Previous studies have focused on ΔP; however, little to no data exist for ΔP with the mode Airway Pressure Release Ventilation (APRV).