Here is the design of a clinical trial:

Official Title: Opioid-Free Anesthesia in Cardiac Surgery

Included conditions:
- Anesthesia

Study Armgroups:
- {'label': 'Standard arm', 'type': 'ACTIVE_COMPARATOR', 'description': 'General anesthesia strategy with morphine:\n\n* Within 10 minutes before the induction of general anesthesia: administration of a placebo of 50 mL of 0.9% NaCl by slow IV\n* The anesthetic induction will be carried out by an intravenous hypnotic (propofol or etomidate) combined with IV curare and remifentanil (morphine derivative) IV for a concentration target of 4 ng / mL.\n* Maintenance of anesthesia will be carried out with propofol or a halogenated gas (sevoflurane or desflurane) in continuous administration (qs bispectral index 40-60) and remifentanil (target concentration 1-10 ng / mL). The administration of curare will be carried out as needed. In order to anticipate the sudden end of the analgesia, an administration of morphine 0.15 mg / kg IV will be carried out 30 minutes before the end of the intervention as recommended', 'interventionNames': ['Drug: Remifentanil']}
- {'label': 'OFA arm', 'type': 'EXPERIMENTAL', 'description': 'General anesthesia strategy without morphine\n\n* Within 10 minutes before the induction of general anesthesia: pre-induction dose of dexmedetomidine 0.5 g / kg and lidocaine 1.5 mg / kg by slow IV.\n* The anesthetic induction will be carried out by an intravenous hypnotic (propofol or etomidate) combined with an IV curare\n* The maintenance of the anesthesia will be carried out by propofol or a halogenated gas (sevoflurane or desflurane) in continuous administration (qsp bispectral index 40-60), dexmedetomidine 0.5-1.0 g / kg / h, lidocaine 2 mg / kg / h. The administration of curare will be carried out as needed.', 'interventionNames': ['Drug: Dexmédétomidine 0.5 g/kg + lidocaine 1.5 mg/kg']}

Interventions:
- {'type': 'DRUG', 'name': 'Dexmédétomidine 0.5 g/kg + lidocaine 1.5 mg/kg', 'description': 'The patient will be anesthetized with Dexmedetomidine 0.5 g / kg + lidocaine 1.5 mg / kg for the induction instead of morphin.', 'armGroupLabels': ['OFA arm'], 'otherNames': ['experimental']}
- {'type': 'DRUG', 'name': 'Remifentanil', 'description': 'The patient will be anesthetized with morphin.', 'armGroupLabels': ['Standard arm'], 'otherNames': ['Control']}

Primary Outcomes:
- {'measure': 'To assess the impact of general anesthesia strategy without the use of opioids (OFA) on the incidence of major postoperative complications related to opioids compared to the reference strategy using opioids.', 'description': 'Composite criterion consisting of the appearance 48 hours after the surgery of an intestinal ileus, and / or of an alteration of the neurological state, and / or of an acute respiratory failure, and / or of a death', 'timeFrame': '48 hours post-surgery'}

Please estimate the sample size based on the assumption: 
The sample size calculation is based on a one-sided Pearson's χ2 test at a 0.05 significance level, with 80% power. The analysis will follow the intention-to-treat principle, and missing values for the primary endpoint will be imputed according to the maximal bias assumption. All statistical tests are two-sided with a 0.05 level required for statistical significance.
Sample size calculation
          The primary endpoint of this study is a composite endpoint defined by the occurrence of at least one of the four major opioid-related complications within 48 hours after cardiac surgery. The sample size was calculated with respect to Pearsonâs Ï2 test at a one-sided 0.05 level, to compare the occurrence of complication between the two groups. In a recent French national survey, 50% of patients presented at least one complication among POCD, ileus or respiratory distress (data not published). In order to obtain 80% power for the difference given by the respective composite endpoint probabilities of 35% and 50% in the OFA and OBA arms, respectively, with one-sided type I error of 5% (reduction in complications of at least 30%), 134 patients will have to be included in each group, hence 268 patients overall. The unilateral characteristic of the test is justified by a previous retrospective study from Guinot et al, where OFA showed a reduction in postoperative outcomes. These data have been recently confirmed by another cohort study from the same authors.32 33