However, 19 cases (42.2%) unimproved hypoxemia required alveolar recruitment procedure with mean maximum setting parameters such as IPmax: 23.8; PEEPmax: 15.1; PIPmax: 38.2; MAPmax: 25.2 cmH20, FiO2max: 85.6% and aiming at low Vt of 5.2 ml / kg.