High-frequency ventilation for acute lung injury and ARDS

In patients with acute lung injury (ALI) and ARDS, conventional mechanical ventilation (CV) may cause additional lung injury from overdistention of th e lung during inspiration, repeated opening and closing of small bronchiole s and alveoli, or from excessive stress at the margins between aerated and atelectatic lung regions. Increasing evidence suggests that smaller tidal v olumes (VTs) and higher end-expiratory lung volumes (EELVs) may be protecti ve from these forms of ventilator-associated lung injury and may improve ou tcomes from ALI/ARDS, High-frequency ventilation (HFV)-based ventilatory st rategies offer two potential advantages over CV for pateints with ALI/ARDS. First, HFV uses very small VTS, allowing higher EELVs with less overdisten tion than is possible with CV. Second, despite the small VTs, high respirat ory rates during HFV allow the maintenance of normal or near-normal Paco(2) levels. In this review, the use of HFV as a lung protective strategy for p atients with ALI/ARDS is discussed.