Changes in computed tomography and ventilation/perfusion mismatch with positive end-expiratory pressure

The purpose was to compare effects of PEEP on computed tomography (CT) and estimated ventilation/perfusion (V/Q) mismatch. Previously, an oxygenation-based method was shown more related to the CT-measured effect of PEEP than lung mechanics [ 1 ], indicating lung aeration is better quantified using V/Q mismatch. Pulmonary shunt and low and high V/Q mismatch can be estimated from varying FIO 2 and measuring ventilation and blood gas contents [ 2 ].