reduced. ECLA systems can now be used for weeks and allow a further reduction in the pressure applied by the ventilator. The amount of inflammation seems to be reduced in comparision with ventilation alone. Close to the time of writing, implementation of awake extracorporeal membrane oxygenation in patients on the lung transplant waiting list, with no analgosedation and intubation for critical hypoxaemia, was reported, and a 30% improvement in survival was shown in comparison with a historical control group. The future vision of this kind of development is the engineering of a biocompatible membrane for lung assist, which can be used in chronic cases for months and years. This may take time however, 30 years ago nobody even considered this possibility. This volume of the European Respiratory Monograph provides a summary of the current state-of-the-art in mechanical ventilation, beginning with the actual pathophysiological concepts and ending with developing technologies. I want to congratulate the Guest Editors of this excellent Monograph, which will be of interest to basic scientists and clinicians, and may have an impact on clinical practice in intensive care medicine. I am convinced that this Monograph will be useful in daily practice. T. Welte Editor in Chief vii