The strategy assessed in this trial not only includes ventilation with a low tidal volume, but also the provision of extrinsic PEEP. There may be some concern that an increased respiratory rate may result in intrinsic PEEP and hemodynamic problems (e.g. decreased cardiac filling, decreased cardiac output, and diminished blood pressure). The panel believes that auto PEEP was not an issue in the Acute Respiratory Distress Syndrome Network study. In addition, in the groups with low tidal volume, at least 10% more oxygen was required to maintain the fraction of inspired oxygen (FiO 2 ), suggesting that there was very little auto PEEP occurring.