The non-sedation ( NONSEDA ) trial is an investigator-initiated , randomised , clinical , parallel-group , multinational trial designed to include 700 patients from at least six ICUs in Denmark , Norway and Sweden.Inclusion criteria are mechanically ventilated patients with expected duration of mechanical ventilation > 24 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 PaO2/FiO2 < 9 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 90 days after randomization .