after being selected, you receive written information about the study and sign a consent form that explains the purpose, procedures, benefits and risks.

the study team records your medical history, current symptoms and performs basic tests such as blood work and a nasopharyngeal swab to confirm influenza infection.

your condition of influenza‑induced acute hypoxemic respiratory failure is documented.

you are assigned by a computer program to receive either the active medication dexamethasone or the placebo sodium chloride solution. the assignment is unknown to you and the treating staff.

the assigned medication is given by intravenous infusion.

if you are in the active group, you receive dexamethasone phosphate at a dose of 6 mg per infusion.

if you are in the placebo group, you receive sodium chloride 0.9 % solution at a dose of 13.5 mg per infusion.

the infusion is performed according to the study schedule that starts on day 0.

each day the clinical staff checks your breathing support, blood pressure, blood sugar and signs of infection.

laboratory tests are repeated as needed, and any adverse events such as high blood sugar, bleeding, new infections or organ problems are recorded.

the number of days you are free from a ventilator, from intensive care and from supplemental oxygen is tracked.

on day 28 the study evaluates whether you are alive, how many days you spent without a ventilator, and how many days you spent outside the intensive care unit.

additional outcomes such as need for extra‑corporeal membrane oxygenation, renal replacement therapy, vasopressors, and length of hospital stay are also recorded.

approximately three months after enrollment, you are asked to complete a quality‑of‑life questionnaire (sf‑36) to assess your overall health status.

any late complications or deaths occurring up to day 90 are documented.