Here is the design of a clinical trial:

Official Title: Cognitive Outcomes After Dexmedetomidine Sedation in Cardiac Surgery Patients: CODEX Trial

Included conditions:
- Delirium
- Cognitive Dysfunction
- Cognition Disorder
- Neurocognitive Disorders
- Mental Disorders
- Confusion
- Neurobehavioral Manifestations
- Neurologic Manifestations
- Nervous System Diseases
- Signs and Symptoms
- Dexmedetomidine
- Hypnotics and Sedatives
- Central Nervous System Depressants
- Physiological Effects of Drugs
- Analgesics, Non-Narcotic
- Analgesics
- Molecular Mechanisms of Pharmacological Action

Study Armgroups:
- {'label': 'Dexmedetomidine Hydrochloride Group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients will receive a loading dose of 1.2 μg/kg dexmedetomidine prior to transfer to CVICU over 20 min immediately postoperative, followed by continuous infusion of 0.3 μg/kg/h for up to 12 hours or until patient is ready for discharge from CVICU (whichever is earlier). Any additional sedatives necessary at the discretion of ICU.', 'interventionNames': ['Drug: Dexmedetomidine Hydrochloride Group']}
- {'label': 'Standard of Care Group', 'type': 'NO_INTERVENTION', 'description': 'Standard sedation protocols will be followed at the discretion of the attending physician.'}

Interventions:
- {'type': 'DRUG', 'name': 'Dexmedetomidine Hydrochloride Group', 'description': 'Dexmedetomidine will be initiated prior to transfer to the CVICU with loading dose of 1.2 ug/kg over approximately 20 minutes. This will be followed by an infusion at 0.3 ug/kg/h in CVICU for up to 12 hours from the time DEX infusion started or until the patient is ready for discharge from the CVICU (whichever is earlier). Any additional sedatives necessary at the discretion of ICU.', 'armGroupLabels': ['Dexmedetomidine Hydrochloride Group'], 'otherNames': ['Dexmedetomidine Hydrochloride']}

Primary Outcomes:
- {'measure': 'Post-operative cognitive dysfunction', 'description': 'Presence of POCD assessed by CogState Brief Battery (CBB)', 'timeFrame': '3 months'}

Please estimate the sample size based on the assumption: 
Î±=0.05, two-sided and Î²=0.2. To account for loss to follow-up (estimated at ~10%).
Statistical analysis and sample size estimation
        
          Sample size calculation
          The sample size is based on the binary, primary outcome of major P-NCD at 3 months with the following assumptions and considerations:
          
            
              Î±=0.05, two-sided and Î²=0.2.
            
            
              Estimated incidence of major P-NCD at 3 months with standard care 25%.
            
            
              Estimated effect size of DEX 20% (relative risk reduction 20% and absolute risk reduction 5% for major P-NCD).
            
          
          This yields a sample size of 1092 per group (2184 total). To account for loss to follow-up (estimated at ~10%), 1200 participants per group (2400 total) will be recruited. There is no minimally clinically important difference for the incidence of P-NCD. The estimated effect size was selected as a balance between clinical relevance and a pragmatic sample size.