IMPROVE Critical Care Study (Pilot)

Inclusion Criteria: Patients mechanically ventilated via an endotracheal tube and receiving intravenous sedation with a hypnotic agent (midazolam or other benzodiazepine) or propofol by continuous infusion. Exclusion Criteria: * Primary intracerebral disorder (includes cardiac arrest with probable hypoxic brain injury; intrac-ranial haemorrhage; head injury causing reduced conscious level prior to intubation) * Patient who is already awake at the time of enrolment defined as RASS ³ -1 * Age \<16 years * Patient not expected to survive the next 24 hours * Patient receiving long term ventilation prior to ICU admission * Patient with a long term tracheostomy prior to ICU admission * Patient transferred sedated and mechanically ventilated from another ICU unless recruitment is possible within 24 hours of first ICU admission * Patient receiving continuous neuromuscular blocking agent at the time of screening for enrolment * Previously enrolled in the trial during a separate ICU admission during this hospital stay * Status epilepticus * Confirmed meningitis or encephalitis at the time of screening for enrolment * Chronic neurological disease interfering with normal neuromuscular function, e.g. motor neurone disease, Guillain-Barre syndrome or inherited neuromyopathies