High-frequency ventilation

High-frequency ventilation (HFV) provides respiratory gas exchange using po sitive airway pressure-driven tidal breaths that are often smaller than ana tomic dead space and breathing frequencies several times faster than normal , Gas transport with HFV involves nonconvective mechanisms such as Taylor d ispersion, coaxial flow and aug-mented diffusion. Devices to deliver HFV in clude the jet (an airway injector delivers jet pulses) and the oscillator ( a piston oscillates a bias flow of fresh gas). The conceptual advantage to HFV is that maximal airway pressures are limited by the small tidal breath and lung recruitment is optimized by the intrinsic positive end expiratory pressure effect. Outcome has been shown to be improved in pediatric patient s at risk for volutrauma, Adult outcome data are still lacking.