[The eternal promise of high frequency ventilation]

High frequency oscillatory ventilation (HFOV) is based on the application of continuous pressure in the respiratory system, which assures oxygenation, on which a small oscillation that permits ventilation is added. Although this ventilation form seems to comply with the requirements necessary to minimize the pulmonary lesion associated to mechanical ventilator-induced lung injury in acute lung injury, as several experimental studies suggest, its advantages in the clinical practice must still be demonstrated. Part of this lack of evidence is due to methodological problems of the studies published. However, the major limitation is that it has not been compared against a conventional ventilation strategy with low volumes/pressures. At present, it seems that high frequency ventilation is limited to cases refractory to conventional ventilation. A more extensive knowledge on how to optimize high frequency ventilation is needed before proposing clinical trials having greater scope.