Ventilation beyond limits
The unique and proprietary Expiratory Ventilation Assistance technology, also known as EVA, actively induces expiration. EVA shortens expiration time, increases the achievable minute volume and reduces the risk of air trapping and the associated risks of barotrauma and circulatory collapse.
As shown in the cross section of Ventrain above, the gas flows via the inlet (1) through a very narrow nozzle (2) and exhaust pipe (3) to the outside. The flow entrains gas from port (4), which is connected to a catheter: active expiration. Insufflation occurs by closing the exhaust pipe. The bypass (5) functions as an on/off switch. When opened, there is no significant positive or negative pressure at the catheter tip, resulting in equilibration/safety mode.
The gas supply should be a high pressure source, as acceleration of the gas flow in the nozzle requires approximately 2 bar at 15 L/min. However, the pressure at the distal end of the catheter connected to Ventrain will not be higher than needed to provide the inspiration flow set on the flow regulator.
The EVA ventilation principle is optimized for a fully or partially obstructed airway. Therefore, EVA combines the advantages of conventional ventilation with jet ventilation: small tubes similar to the ones used in jet ventilation can be applied but, similar to conventional ventilation, the remaining airway does not need to be rather open.
While conventional ventilation depends on relatively high gas flows to obtain an effective gas exchange in the lungs and jet ventilation relies on high inspiration pressures, EVA ventilates by enhancing both inspiration and expiration, promoting gas exchange by the resulting turbulences in the lungs.
©2016 Ventrain, Cricath, Tritube and the EVA technology are registered trademarks of Ventinova Medical B.V. All rights reserved.