Center of ventilation.

Ventilation distribution during individual measurement time points represented by the geometrical center of ventilation. The center of ventilation is given in percent of the anteroposterior chest diameter. Values above 50 indicate a location in the dorsal half of the chest cross-section. The median, the 25th and the 75th percentile, minimum and maximum values of ten animals are shown. The gray areas in the diagram show the positive end-expiratory pressure (PEEP) values during the individual measurement time points. Significant differences between corresponding high V_T and low V_T are indicated. Every group with ALI and high PEEP is significantly different from normal lung and ALI with PEEP 10 cm H₂O (Time point 2). Left Y axis: center of ventilation, right Y axis: PEEP. High V_T, ventilation with 10 ml/kg BW, low V_T, ventilation with 5 ml/kg BW.