 Levosimendan is a relatively new drug that improves cardiac contractility in patients with heart failure. Its main mechanism of action is enhanced binding of calcium to the myocardial contractile proteins. Recent data from our lab showed that levosimendan improves contractility of human diaphragm in vitro muscle fibers from COPD patient diaphragm and in vivo healthy subjects. Accordingly, levosimendan may appear of value in the treatment of disorders associated with impaired respiratory muscle function, such as mechanically ventilated patients.We hypothesize that levosimendan could improve respiratory muscle function in mechanically ventilated patients commencing a CPAP trial. 