The effect of early sedation with dexmedetomidine compared with placebo on 90-day mortality in older critically ill patients

INTERVENTION: Intravenous infusion of dexmedetomidine started shortly after commencement of mechanical ventilation, at a recommended dose of 1 mcg/kg/hr without a loading dose. The infusion will be adjusted between 0 and 1 mcg/kg/hr to achieve target sedation assessed by the Richmond Agitation Sedation Scale (RASS). The default target is RASS score of ‐1 to+1. The infusion would continue in intensive care until sedation is no longer required or to a max of 28‐days whichever comes first. The need for ongoing sedation will be determined by the attending clinician based on frequent clinical assessment. Adherence to the intervention will be monitored by onsite research support staff and the study PI at individual sites. In addition, monitoring through study website via built in queries will be regularly conducted. CONDITION: Anaesthesiology ‐ Other anaesthesiology Critically ill patients;Mechanical Ventilation;Sedation; ; Critically ill patients ; Mechanical Ventilation ; Sedation PRIMARY OUTCOME: All‐cause mortality will be collected through a phone follow‐up by the sites research support staff. This is then entered into the study database.[90‐days following randomization] SECONDARY OUTCOME: A composite score of Number of days alive and ventilator free collected directly from medical records and entered into study database.[at 28 days following randomization] Hospital length of stay in survivors. This is collected directly from medical records and entered into study database.[Hospital discharge ] A composite of Number of days alive and free of coma and delirium. This is collected through medical records and direct patient assessment for delirium, coma (RASS of < or = ‐4 unresponsive to voice or painful stimulus). [at 28 days following randomization ] Duration of mechanical ventilation in survivors This is collected directly from medical records and entered into study database.[ICU discharge ] Major Adverse Kidney Events (Mortality + Acute Kidney Injury > stage II, defined by Kidney Disease Improving Global Outcome (KDIGO) definition). This is collected directly from medical records and entered into study database.[at 28 days following randomization] INCLUSION CRITERIA: 1. Age is equal to or older than 65 years 2. Intubated and receiving invasive mechanical ventilation in an intensive care unit 3. The treating clinicians believe that the patient will remain intubated and ventilated until the day after tomorrow (unlikely to be extubated next day) 4. The patient requires immediate ongoing sedative medication for comfort, safety and to facilitate the delivery of life support measures.