Maximal compliance (Cmax) and Gruenwald indexes and protein concentrations in bronchoalveolar lavage (BAL) fluid after 4 h of mechanical ventilation with three different ventilation strategies
| Low PIP/PEEP | High PIP/PEEP | High PIP/ZEEP | |
| BAL protein µg·mL−1 | 53.8±11.5 | 96.0±8.8* | 329.0±54.6*** |
| Cmax mL·cmH2O−1·kg−1 | 4.96±0.55 | 4.89±0.61 | 2.46±0.24*** |
| Gruenwald index | 1.09±0.06 | 1.06±0.09 | 0.53±0.14*** |
PIP: peak inspiratory pressure
PEEP: positive end-expiratory pressure
ZEEP: zero PEEP
*: p<0.05 high PIP/PEEP versus low PIP/PEEP
***: p<0.001 high PIP/ZEEP versus high PIP/PEEP and low PIP/PEEP