The following letters are in response to Point:Counterpoint: High-frequency ventilation is/is not the optimal physiological approach to ventilate ARDS patients.
To the Editor: Mechanical ventilation (MV) may aggravate lung injury due to two primary types of injury: volu- and atelectrauma. There is a variety of experimental data clearly showing that avoidance of alveolar overdistension and repetitive collapse and reopening of damaged alveolar lung units leads to lung protection (3). In clinical studies the application of lower tidal volumes (VT) was associated with improvements in outcome (1). Outcome was not affected by the level of positive- end-expiratory pressure (2). Thus low-VT ventilation seems to be the key factor to reduce mortality, whereas the optimal VT remains unclear. At this point, there is growing evidence to suggest that a further VT reduction might be beneficial for ARDS patients. Due to a number of different CO2-removal mechanisms, VT during high-frequency oscillatory ventilation (HFOV) may further be decreased (in the range of 1.0–2.0 ml/kg), thereby minimizing the potential of volutrauma (4, 5, 6). During conventional MV, a further VT reduction (