Please assess the completion status of the following clinical trial:

Trial Title: Ketamine Versus Dexmedetomidine for Prevention of Postoperative Delirium

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: None
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion Criteria:~* 1- Patients aged ≥ 65 years. 2- Scheduled for visceral, orthopedic, vascular, obstetric, urology, or plastic surgery.~Exclusion Criteria:~* 1- Delirium upon hospital admission or development of delirium prior to surgery stated by family members.~  2- Mini-Mental State Examination (MMSE) score \< 24 points 3- Delirium Observation Scale (DOS) ≥4 points 4- preoperative neurological diseases affecting cognitive function (such as vascular dementia) 5- High risk for postoperative treatment in the intensive care unit (ICU) 6- Known to have dexmedetomidine and or ketamine intolerance. 7- Lack of cooperation or communication. 8- Parkinson's disease, parkinsonism, intake of dopaminergic drugs (levodopa, dopamine agonists) 9- Epilepsy. 10- Patients on steroid therapy 11- severe liver and renal insufficiency

- Gender: ALL
- Minimum Age: 60 Years
- Maximum Age: 80 Years
- Healthy Volunteers: f

Study Arms:
- Ketamine group (Type: ACTIVE_COMPARATOR): An anesthesiologist who is not involved in the study will prepare the intervention, ketamine1 mg/kg BW, in a standardized syringe with the same volume. Patients will be given the active comparator or placebo only once right before the induction of anesthesia.~All patients will be received standardized GA protocol as follows:~1. Induction with propofol (1-2 mg/kg body weight).~2. Esmeron (1 mg/kg body weight).~3. Isoflurane is a volatile anesthetic agent in 50% O2 and air.~4. Fentanyl (1 microgram/kg body weight) during induction of anesthesia and the total doses of fentanyl used during the operation will be recorded.~5. All patients received a combination of intravenous paracetamol 1 g and ketorolac 30 mg at the conclusion of surgery. This regimen will be repeated regularly every 8 h.
- Dexmedetomidine group (Type: ACTIVE_COMPARATOR): An anesthesiologist who is not involved in the study will prepare the intervention, Dexmedetomidine 1 μg/kg BW, in a standardized syringe with the same volume. Patients will be given the active comparator or placebo only once right before the induction of anesthesia.~All patients will be received standardized GA protocol as follows:~1. Induction with propofol (1-2 mg/kg body weight).~2. Esmeron (1 mg/kg body weight).~3. Isoflurane is a volatile anesthetic agent in 50% O2 and air.~4. Fentanyl (1 microgram/kg body weight) during induction of anesthesia and the total doses of fentanyl used during the operation will be recorded.~5. All patients received a combination of intravenous paracetamol 1 g and ketorolac 30 mg at the conclusion of surgery. This regimen will be repeated regularly every 8 h.
- Placebo group (Type: PLACEBO_COMPARATOR): An anesthesiologist who is not involved in the study will prepare the intervention, normal saline 0.9% in a standardized syringe with the same volume. Patients will be given the active comparator or placebo only once right before the induction of anesthesia.~All patients will be received standardized GA protocol as follows:~1. Induction with propofol (1-2 mg/kg body weight).~2. Esmeron (1 mg/kg body weight).~3. Isoflurane is a volatile anesthetic agent in 50% O2 and air.~4. Fentanyl (1 microgram/kg body weight) during induction of anesthesia and the total doses of fentanyl used during the operation will be recorded.~5. All patients received a combination of intravenous paracetamol 1 g and ketorolac 30 mg at the conclusion of surgery. This regimen will be repeated regularly every 8 h.

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