Expiratory flow control: a novel mode of ventilation for the injured lung

BJA: British Journal of Anaesthesia

Achieving adequate gas exchange whilst minimising ventilator induced lung inury is a major challenge in intensive care. The world of ICU ventilation is rich with novel proprietary modes but so far, none have proven an outcome benefit in ARDS. Whilst the differences between various modes are often subtle, most focus on modifying the inspiratory phase of the respiratory cycle, whilst maintaining a constant level of end-expiratory pressure. A group from the Division of Experimental Anaesthesiology at University Medical Centre in Freiburg have recently customised a standard ventilator to control the expiratory phase in a volume controlled mode. Dr Stefan Schumann, the biomedical engineer on the project, talks to us about the physiological rationale for flow-controlled expiration and in simple terms, how they were able to achieve it. Dr Schumann then goes on to describe their experiments in a porcine lung injury model and the encouraging results produced by this nascent technology.