Fig. 1. Consolidated Standards of Reporting Trials (CONSORT) diagram. BAL = bronchoalveolar lavage; HVT/ZEEP = tidal volumes of 12 ml/kg ideal body weight and no positive end-expiratory pressure; LVT/PEEP = tidal volumes of 6 ml/kg ideal body weight and 10 cm H2O positive end-expiratory pressure; MV = mechanical ventilation.