Impact of the COVID-19 pandemic on the association between sepsis etiology and mortality among ICU patients in France

OBJECTIVES: This study assessed the impact of the COVID-19 pandemic on in-hospital/90-day mortality factors, focusing on sepsis etiology among ICU sepsis patients. METHODS: We analyzed 604,517 ICU sepsis patients (≥15 years) from French national database (2018-2022). Sepsis was identified using explicit and implicit ICD-10 infection codes. We compared pre-pandemic and pandemic mortality risk using separate multivariate logistic regression models for patients with and without co-infections, adjusted for demographics, comorbidities, and infection severity. RESULTS: Overall in-hospital mortality was 29.2% and 90-day mortality was 34.0%. Pre-pandemic, viral sepsis had lower in-hospital mortality than bacterial sepsis, with co-infections (aOR= 0.63 [99% CI=0.51-0.77]) and without (aOR=0.67 [99% CI=0.60-0.74]). During the pandemic, this reversed: viral sepsis (mainly COVID-19) showed higher mortality with co-infections (aOR=1.41 [99% CI=1.15-1.71]) and equivalent risk without (aOR=1.01 [99% CI= 0.97-1.05]) compared with bacterial sepsis. Among patients without co-infections, mortality risk was higher for fungal/parasitic sepsis than for bacterial sepsis during the pandemic. CONCLUSIONS: The pandemic modified sepsis-mortality associations, particularly for viral versus bacterial in-hospital mortality. These findings highlight the substantial mortality burden of COVID-19-related viral sepsis and underscore the need for specific viral sepsis ICD codes to accurately identify and manage this condition in future pandemics.