Surfactant replacement therapy (SRT) improves oxygenation and survival in NRDS and some infant ARDS. SRT was tried in adult ARDS with conflicting results. Research by Filoche and Grotberg helped to understand the failure of previous clinical trials and yielded a strong scientific rationale for SRT success, now allowing to design a new administration protocol for SRT in adults, to be tested by this clinical trial in COVID-19 adult ARDS patients.

Patients will be randomized to receive either a bronchial fibroscopy alone (with aspiration of secretions) or a bronchial fibroscopy with administration of 3 mL/kg of a solution of poractant alpha diluted to 16 mg/mL and distributed into each of the 5 lobar bronchi.

Inclusion Criteria:

• At least 18 years
• Intensive care unit admission.
• Intubation and mechanical ventilation since less than 72h.
• Positive end-expiratory pressure ≥ 5 cmH2O.
• Acute respiratory distress syndrome following Berlin definition.
• COVID-19
• PaO2/FiO2 ratio < 150 mmHg during at least 3 hours despite PEP trial.
• Compliance of the respiratory system < 50 mL/cmH2O

Exclusion Criteria:

• Contraindication to prone position.
• Pregnancy.
• Weight < 40 kg
• height < 140 cm or height > 190 cm.
• Profuse bronchorrhea (at least 1 succion per hour during 3 hours).
• Other significant cause than ARDS to the respiratory failure.
• Decision to limit active therapies.
• No arterial line in place.
• Obesity with weight / height ratio > 1 kg / cm.
• Impossible to give neuromuscular blockers (e.g. drug unavailable owing to global pandemia).
• Severe chronic respiratory failure with oxygen at home.
• Other severe acute or chronic organ faillure (eg severe liver cirrhosis, severe chronic cardiac failure).
• History of pneumonectomy or pulmonary lobectomy.
• Patient scheduled for extracorporeal membrane oxygenation.
• Known hypersensibility to Curosurf.
• Contraindication to bronchial fibroscopy.
• Person under legal protection.