Improving our understanding of respiratory muscle training to facilitate weaning from mechanical ventilation in the ICU.

A majority of mechanically ventilated patients develop respiratory muscle weakness during critical illness. Rehabilitation efforts in the intensive care unit (ICU) have so far largely focused on peripheral muscle dysfunction, whereas respiratory muscle rehabilitation has received relatively less attention. The potential value of respiratory muscle conditioning interventions are supported by observations showing that respiratory muscle weakness is associated with prolonged duration of mechanical ventilation, difficult weaning, and increased ICU mortality. In two recent systematic reviews it was moreover observed that inspiratory muscle training (IMT) can improve respiratory muscle function, and might facilitate weaning from mechanical ventilation. The optimal approach to respiratory muscle conditioning remains however largely uncertain. In order to gain more insight into how an optimal training stimulus should be offered to patients on prolonged mechanical ventilation we therefore aim to perform comprehensive evaluations of physiological adaptations and changes in both static and dynamic respiratory muscle function in response to three different training regimens in patients on prolonged mechanical ventilation.