Patients who needed mechanical ventilation were managed with pressure-cycled ventilation, with a low tidal volume (target 6 ml/kg) open-lung strategy of ventilation, and a positive endexpiratory pressure (PEEP) titrated based on FiO 2 for goal plateau pressure (Pplat) < 30 cm H 2 O and SpO 2 88%-90% according to ARDS Network protocol. In some cases, due to refractory hypoxemia, PEEP levels of 14 to 16 cm H 2 O were applied. In all patients, recruitment maneuvers were usedcontinuous positive airway pressure 35-40 cm H 2 O for 30 swith short-term improvements in oxygenation in three of five patients (initial mean oxygen saturation rate increased from 88% to 94%). Neuromuscular blockade was used in two patients ( Table 2) . Despite the aforementioned ventilatory strategy, this particular group of patients developed refractory persistent hypoxemia. Lung mechanics of patients showed very low static and dynamic compliance and high airway resistance.