NCT04347980.

Methods	Trial design: single‐blinded (participants) RCT Sample size: 122 Setting: inpatient Language: French, English Number of centres: multicentre, no concrete information Type of intervention (treatment/prevention): treatment
Participants	Inclusion criteria Patient > 18 years old Patient affiliated to a health insurance plan Patient who has given their free, informed and written consent or patient for whom an independent doctor has given their signed consent as part of an emergency procedure Kaliaemia > 3.5 mmol/L Patient diagnosed COVID‐19‐positive by RT‐PCR and/or CT The diagnosis of COVID‐19 will be made if: patient with radiological images strongly suggestive of a chest scan associated with respiratory symptoms, without other obvious aetiologies; OR patient with suggestive respiratory symptoms associated with a positive RT‐PCR. Patients admitted to ICU with acute respiratory distress syndrome secondary to COVID‐19, intubated for < 5 days with one of: hypoxaemia defined by PaO2/FiO2 ratio < 100 after 2 sessions of prone position an alteration in pulmonary compliance (tidal volume divided by plateau pressure minus positive expiratory pressure) immediately or over the first 96 h after the start of ARDS defined by: immediately: impossibility of maintaining a plateau pressure < 30 cm of water in a ventilated patient with a tidal volume of 6 mL/kg of weight predicted by the size and a positive expiratory pressure at 10 cm of water, during the course of the evolution: decrease in compliance by 20% compared to the initial compliance (day of treatment of the intubated and ventilated patient) We define the start date of ARDS by the day and time when the patient is intubated and ventilated with regard to our definition of COVID‐19 Exclusion criteria Patient under guardianship or curator Patient with plausible alternate diagnosis ARDS evolving for > 4 days Contraindication to hydroxychloroquine: known allergy or intolerance to the hydroxychloroquine or to one of the excipients of the drug, in particular to lactose; documented QT prolongation and/or known risk factors for QT prolongation (including ongoing treatment with citalopram, escitalopram, hydroxyzine, domperidone or piperaquine), retinopathies Contraindication to dexamethasone: known allergy or intolerance to dexamethasone or to one of the excipients of the drug, another evolving virosis (hepatitis, herpes, chickenpox, shingles), severe coagulation disorder Uncontrolled septic shock Untreated active infection or treated < 24 h Long‐term patient treated with corticosteroids (> 20 mg/day) or hydroxychloroquine Immunocompromised patients: AIDS, bone marrow or solid organ transplant recipients Pregnant women Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency
Interventions	Details of intervention Dose: dexamethasone (20 mg for 5 days followed by 10 mg for 5 days) combined with 600 mg/d dose of hydroxychloroquine for 10 days Route of administration: IV Treatment details of control group (e.g. dose, route of administration): 200 mg x 3/d enterally from J1 of the hydroxychloroquine for 10 days. If the patient is extubated before the 10th day, he will receive his last dose of hydroxychloroquine before. Concomitant therapy: no information
Outcomes	Primary study outcome: day 28 mortality
Notes	Recruitment status: terminated (ANSM (Agence nationale de sécurité du médicament et des produits de santé) Recommendation) Prospective completion date: August 2020 Date last update was posted: 17 April 2020 Sponsor/funding: Centre Chirurgical Marie Lannelongue