The non-sedation ( NONSEDA ) trial is an investigator-initiated , randomised , clinical , parallel-group , multinational trial designed to include @ patients from at least six ICUs in Denmark , Norway and Sweden.Inclusion criteria are mechanically ventilated patients with expected duration of mechanical ventilation > @ hours.Exclusion criteria are non-intubated patients , patients with severe head trauma , coma at admission or status epilepticus , patients treated with therapeutic hypothermia , patients with PaO@/FiO@ < @ where sedation might be necessary to ensure sufficient oxygenation or place the patient in prone position.Experimental intervention is non-sedation supplemented with pain management during mechanical ventilation.Control intervention is sedation with a daily wake-up trial.The primary outcome will be all cause mortality at @ days after randomization .