[Current concepts of augmented spontaneous breathing: new modes of effort-adapted weaning]

The use of augmented spontaneous breathing is an important component in a bundle concept of weaning from mechanical ventilation as it was demonstrated that controlled ventilation with diaphragmatic underuse induces rapid muscle atrophy and impairs successful weaning. On the other hand spontaneous breathing is often associated with disturbed patient-ventilator interaction resulting in asynchrony (e.g. ineffective triggering, early termination of inspiration and overflow or underflow). It was shown that asynchrony can impair gas exchange, increase work of breathing and enhance deleterious aspects of mechanical ventilation. Concepts of assisted breathing, such as proportional assist ventilation (PAV), adaptive support ventilation (ASV) and neurally adjusted ventilatory support (NAVA), which are intended to increase effort-adapted spontaneous breathing by an electronic or physiological closed loop feedback system with the patient's work of breathing were developed more than 20 years ago and are currently experiencing a renaissance. It was shown in some smaller clinical investigations that these newer modes are able to improve patient-ventilator interaction, to reduce the burden on respiratory muscles and to increase ventilation comfort. Although large randomized controlled studies are lacking, effort-adapted modes of augmented breathing will become a routine part in the management of weaning from mechanical ventilation.