Shorter Weaning From Invasive Ventilation With Levosimendan

Inclusion Criteria: * Invasively ventilated \> 48 hours. * Failed at least one spontaneous breathing trial (SBT). * Age above 18 years. * Female patients with age \< 60 must have a negative pregnancy test (blood or urine) prior to participation. Exclusion Criteria: * Pre-existing neuromuscular disease (congenital or acquired) * Endotracheally intubated primarily for neurological reason (e.g., traumatic brain injury, intracranial haemorrhage, epilepsy, intracranial infection), or developed severe intracranial haemorrhage/infarction during ICU stay. * Contra-indications for levosimendan: severe renal failure (creatinine clearance \<30mL/min) unless managed with appropriate continuous kidney replacement therapy (such as CRRT), severe liver failure (Child-Pugh class C), history of torsade des pointes; known significant mechanical obstructions affecting ventricular filling/ outflow or both; prolonged QTc interval (QTc \> 470ms); breast feeding; known hypersensitivity to levosimendan. * Treatment with intermittent haemodialysis. * Treatment limitation decision in place: do not reintubate * Previous treatment with levosimendan within 30 days. * Currently in another interventional trial that might interact with study drug or primary outcome.