Existence and relevance of fulminant severe community-acquired pneumonia.

BACKGROUND: Severe community-acquired pneumonia (sCAP) is a major contributor to global hospital mortality, with some patients rapidly progressing to death within a few days due to acute respiratory distress syndrome (ARDS), septic shock, or multiorgan failure (MOFS). Despite the significant health burden, these cases remain poorly defined, often overlooked in clinical practice, and insufficiently addressed in existing guidelines. METHODS: In this multicenter retrospective study, we analyzed 1,517 hospitalized patients with sCAP for assessing the incidence of fulminant pneumonia -defined as sCAP leading to death within 7 days from hospital admission- and to identify factors associated with either an increased or reduced risk of unfavorable outcome. RESULTS: Our findings revealed a 5.9% incidence of fulminant pneumonia, with early death primarily due to ARDS (93%), sepsis (70%), and MOFS (73%). Older age, obesity, diabetes, cardiovascular disease, and elevated serum creatinine were associated with increased risk, while early corticosteroid administration was associated with a significant mortality reduction within seven days, both in the univariate and multivariate analyses (OR 0.22, CI 95% 0.12–0.38, p < 0.001). Baseline respiratory impairment and inflammatory markers were not associated with early mortality. CONCLUSION: These findings highlight the importance of recognizing sCAP as a time-dependent condition, requiring early identification and treatment of cases at risk for developing fulminant pneumonia at hospital admission. Larger studies and randomized controlled trials are necessary to validate these findings and optimize treatment strategies. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT06516601.