Please assess the completion status of the following clinical trial:

Trial Title: Dexmedetomidine to Lessen Intensive Care Unit (ICU) Agitation

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE2/PHASE3
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~Patients will be eligible for the study if, in the opinion of the treating clinician, they continue to require mechanical ventilation only because their degree of agitation requires such a high dose of sedative medication (midazolam or propofol, the only commonly used specific sedatives in our unit) that extubation is not possible, AND in the opinion of their treating intensivist their agitation is so severe as to make lessening their sedation unsafe.~These criteria will be objectively quantified as follows:~* they have required either mechanical restraint and/or anti-delirium or sedative medication in the 4 hours prior to seeking consent AND~* their Confusion Assessment Method for the ICU (CAM-ICU) test is positive for delirium in the 4 hours prior to seeking consent AND~* their Motor Activity Assessment Scale (MAAS) score is 5 or more in the 4 hours prior to seeking consent, confirming psychomotor agitation AND~* their SOFA score is less than or equal to 5 in the 4 hours prior to seeking consent, predicting a mortality or around 5%.~Exclusion Criteria:~* Age less than 18 years old~* Pregnancy or breastfeeding~* Advanced dementia (in the premorbid state requiring professional nursing care)~* Open or closed head injury~* Death is deemed imminent and inevitable~* The patient has previously been enrolled in the DahLIA study~* Patients who could not be extubated, or who would be intubated within the following 48 hours, even if delirium or agitation were corrected. This will include:~  * Patients receiving high dose opioid for analgesia (not sedation) ( \> 40 mg/morphine/day)~ * Patients shortly to return to the operating theatre~ * Patients undergoing repeated invasive procedures, in whom it is desirable to maintain deep sedation~ * Patients likely to require ongoing airway protection or control, or ventilatory support (for example, spinal patients with an inadequate vital capacity)~* Known allergy to haloperidol or alpha 2 agonists

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Dexmedetomidine (Type: ACTIVE_COMPARATOR): Dexmedetomidine will be administered intravenously as a maintenance infusion of 0.2 to 1.5 mcg/kg/hour, commencing at 0.5 mcg/kg/hour and titrated according to effect, for as long as deemed necessary by the treating physician. Specifically, the study medication may be (as recommended by the manufacturer) continued after extubation, and if discontinued may be restarted at any time up until ICU discharge. The clinician will have the option of using a loading dose of 1.0 mcg/kg IV over 20 minutes, as recommended by the manufacturer.~Bedside nursing staff will adjust drug infusion rates as necessary, in consultation with the treating physician, aiming to achieve a Riker Sedation-Agitation Scale 20 score of 4.
- Saline placebo (Type: PLACEBO_COMPARATOR): An identical syringe to that in the intervention arm, but which does not contain dexmedetomidine, will be provided. The initial rate of infusion and subsequent adjustments will be the same as in the dexmedetomidine group.

Based on this trial design, predict the completion outcome and termination type (if applicable).