Study: NCT04344730

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Dexamethasone injection
Description: Box of 10 DEXAMETHASONE 20 mg / 5 ml, solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Dexamethasone injection
Description: Box of 10 DEXAMETHASONE 20 mg / 5 ml, solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Dexamethasone injection
Description: Box of 10 DEXAMETHASONE 20 mg / 5 ml, solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Dexamethasone injection
Description: Box of 10 DEXAMETHASONE 20 mg / 5 ml, solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: placebo
Description: Box of 10 NaCl 0,9% , solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: placebo
Description: Box of 10 NaCl 0,9% , solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: placebo
Description: Box of 10 NaCl 0,9% , solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: placebo
Description: Box of 10 NaCl 0,9% , solution for injection in ampoule of 5mL. Each allocated box contains complete treatment from D1 to D10 for one patient.

Intervention type: PROCEDURE
Group type: PLACEBO_COMPARATOR
Intervention: conventional oxygen
Description: The oxygen flow will be adjusted to maintain an oxygen saturation level of 92% or more, as measured by means of pulse oximetry (SpO2)

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: conventional oxygen
Description: The oxygen flow will be adjusted to maintain an oxygen saturation level of 92% or more, as measured by means of pulse oximetry (SpO2)

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: CPAP
Description: Patients assigned to the CPAP plus oxygen group will receive periods of CPAP in addition to the standard treatment.The oxygen flow will be adjusted to maintain an oxygen saturation level of 92% or more, as measured by means of pulse oximetry (SpO2)

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: CPAP
Description: Patients assigned to the CPAP plus oxygen group will receive periods of CPAP in addition to the standard treatment.The oxygen flow will be adjusted to maintain an oxygen saturation level of 92% or more, as measured by means of pulse oximetry (SpO2)

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: HFNO
Description: TIn the high-flow-nasal cannula group, oxygen will be delivered through a heated humidifier (Airvo-2, Fisher and Paykel Healthcare) and applied continuously through large-bore binasal prongs, with a gas flow rate of 30 liters per minute and adjusted based on the clinical response. FiO2 will be adjusted for the target SpO2