Here is the design of a clinical trial:

Official Title: Extra-Corporeal Carbon Dioxide Removal for Acute Decompensation of Chronic Obstructive Pulmonary Disease: A Randomized Clinical Trial (The ORION Study)

Included conditions:
- Pulmonary Disease, Chronic Obstructive

Study Armgroups:
- {'label': 'Standard of Care (NIV)', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients in the control group will be treated with non-invasive ventilation only.', 'interventionNames': ['Device: NIV']}
- {'label': 'Extracorporeal CO2 Removal (NIV+ECCO2R)', 'type': 'EXPERIMENTAL', 'description': 'Patients in the treatment group will be treated with non-invasive ventilation combined with Extracorporeal CO2 Removal.', 'interventionNames': ['Device: ECCO2R', 'Device: NIV']}

Interventions:
- {'type': 'DEVICE', 'name': 'ECCO2R', 'description': 'Extracorporeal CO2 Removal', 'armGroupLabels': ['Extracorporeal CO2 Removal (NIV+ECCO2R)']}
- {'type': 'DEVICE', 'name': 'NIV', 'description': 'Non-invasive ventilation', 'armGroupLabels': ['Extracorporeal CO2 Removal (NIV+ECCO2R)', 'Standard of Care (NIV)']}

Primary Outcomes:
- {'measure': 'Combined 28-day mortality or surrogate events', 'description': 'Incidence of death, prolonged mechanical ventilation, development of septic shock, development of severe hypoxemia, second episode of COPD exacerbation', 'timeFrame': '28 days after enrollment'}

Please estimate the sample size based on the assumption: 
The study uses a two-sided log-rank test with a 0.05 significance level and 90% power. The study duration is 25 months, with 24 months for accrual and 1 month for follow-up. No dropouts or crossovers are assumed.
Sample size
        A two-sided log-rank test with an overall sample size of 284 subjects (142 in the control group and 142 in the treatment group) achieves 90% power at a 0.05 significance level to detect a hazard ratio of 0.67 when the proportion surviving without events in the control group is 40% (we estimated a combined proportion of death, prolonged mechanical ventilation, septic shock, severe hypoxemia and second episode of COPD exacerbation of 60% [23â33]). The study will last 25 months of which 24 months to accrual and 1 month of follow up. No subject will drop out of the control/treatment group. We assume no cases of switch (crossing-over) between the arms: the proportion of the control group that switches to a group with a risk rate equal to the treatment group is equal to zero (and vice versa).
        This study has been designed to demonstrate a relative increase of 35% in the event free survival (from 40% to 54%), assuming the above-mentioned parameters.