LUNG INFECTION in ICU (LUNG-I3)

Inclusion Criteria:

All the following criteria

• Age 18 years or greater

• Severe ICU patients hospitalized for one of the above diseases:

• Septic shock (requirement of vasopressor to maintain a mean arterial pressureof 65 mm Hg or greater and serum lactate level greater than 2 mmol/L (>18mg/dL) in the absence of hypovolemia) caused either by pneumonia (n=20) oranother source n=20)

• Severe trauma (level I and II), Injury Severity Score ≥ 25 OR

• Burn with TBSA over 20%

• NAD > 0.1 µg/kg/min

• At least 2 SOFA criteria ≥ 2 points

Exclusion Criteria:

• Aspiration pneumonia

• Unable to obtain a valid and written consent from a patient or their legallyauthorized representative in accordance with the local regulatory instances (thisincludes in FR: Person not affiliated to a health insurance scheme, or not abeneficiary of such a scheme. Persons who are the subject of a legal protectionorder. Person with restricted freedom following a legal or administrative decisionand a person admitted without their consent pursuant to Articles L.3212-1 and 3213-1, which are not included in Article L.1121-8 of the French Public HealthCode.)

• COPD

• Smoke inhalation in burn patients

• Participation in an intervention study

• Pregnant or breastfeeding women

• Immunocompromised patients, defined as

• patients with solid tumors with chemotherapy in the last 3 months or aprogressive metastatic disease

• hematologic malignancies

• solid organ transplantation

• HIV infection with or without AIDS

• treatment with corticosteroids (> 3 months at any dosage or ≥ 1 mg/kgprednisone equivalent per day for > 7 day)

• treatment with other immunosuppressive drugs.