Expiratory flushing of airways: a method to reduce deadspace ventilation.

A jet of fresh gas entering the trachea during the last part of expiration, expiratory flushing of airways (EFA), may during mechanical ventilation bring the fresh gas interface into the trachea to reduce deadspace. EFA, delivered in a variety of modes, was tested in healthy dogs. EFA allowed tidal volume, peak and mean airway pressure to be reduced by about 25%. EFA was administered in the form of pulses with frequencies 2-8 Hz, and as a continuous flow. The mode was of little importance. EFA was found to be efficient and should be clinically tested.