Severe community-acquired pneumonia (CAP) and community-acquired aspiration pneumonia (CAAP) are common reasons for adult emergency department visits and subsequent admission to the intensive care unit (ICU). Three bacteria are primarily implicated in this type of pneumonia: Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus.

Empirical antibiotic therapy for this condition is currently based on the use of beta-lactams. While third-generation cephalosporins (3GC) remain the beta-lactam of choice in French guidelines for CAP, the combination of Amoxicillin/Clavulanic Acid (AMC) at high-dose (>3g/day) could represent an alternative. AMC is already recommended for severe CAAP and for non-severe CAP in France, and for severe CAP in the UK and the United States. Furthermore, good practice guidelines encourage the use of empirical antibiotic therapies that are then subsequently tailored to the narrowest-spectrum agents based on antibiograms. This approach aims to limit the emergence of multidrug-resistant bacteria and reduce the risk of Clostridioides difficile colitis, which can increase patient morbidity and mortality.

This study aims to evaluate the susceptibility to AMC and 3GC, and to describe the empirical antibiotic therapies used and their subsequent adjustments, in adult patients admitted to the ICU for severe CAP and CAAP documented with Streptococcus pneumoniae, and/or Haemophilus influenzae, and/or Staphylococcus aureus.

Observational retrospective monocentric cohort including all the consecutive adult ICU patients admitted from january 2018 to november 2022 with a CAP or a CAAP documented to Streptococcus pneumoniae, and/or Haemophilus influenzae, and/or Staphylococcus aureus.

Inclusion Criteria:

1. Patient admitted to the ICU at Sainte-Musse Hospital between January 2018 and December 2022.
2. Diagnosis of severe CAP or CAAP within 48 hours of hospital admission, documented with Streptococcus pneumoniae, and/or Haemophilus influenzae, and/or Staphylococcus aureus (confirmed by blood culture and/or a respiratory sample), with an available antibiogram.

Exclusion Criteria:

1. Patient under 18 years old.
2. Patient hospitalized within 3 months prior to hospital admission.
3. Infectious documentation of another pathogen within 48 hours of hospital admission.
4. Nosocomial pneumonia.
5. Patient under legal guardianship (inmate, legal ward, curatorship).

Patients admitted to the ICU at Sainte-Musse Hospital between January 2018 and December 2022 with a diagnosis of severe CAP or CAAP