Predictors of adverse outcomes of ICU-acquired sepsis in the italian SPIN-UTI network

Healthcare-associated infections (HAIs) can trigger sepsis particularly in patients who are already at high risk, such as those admitted in Intensive Care Units (ICUs). The present study was conducted using data collected during a ten-years period in the framework of the Italian Nosocomial Infections Surveillance in ICUs - SPIN-UTI network, in order to report the frequency of ICU-acquired sepsis and to identify predictor factors associated with adverse outcomes. The SPIN-UTI network adopted the European protocols for patient-based surveillance (HELICS and HAI-Net ICU protocols). For sepsis the definition of the ACCP/SCCM Consensus Conference Committee (1992) was adopted. From 2008 to 2017, 13,512 patients were enrolled and among HAIs episodes, 47.0% led to sepsis. In sepsis episodes, Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa were the most frequently isolated microorganisms. Mortality (RR: 1.466; CI95%: 1.304-1.649) and mean length of ICU-stay (31.2 versus 24.3 days) were significantly higher in patients with ICU-acquired sepsis than in patients without sepsis. Regression analyses demonstrated that SAPS II score above the median value, antibiotic treatment in 48 hours before or after ICU admission, surgical intervention and A. baumannii and/or K. pneumoniae HAIs were significantly associated to sepsis risk. Furthermore, SAPS II score and older age were independent predictors of mortality in patients with sepsis. Our study demonstrates that ICU-acquired sepsis greatly increases mortality and length of ICU-stay in ICU patients. The identification of the predictors of sepsis occurrence and mortality is essential to design interventions for the prevention of infection, sepsis and of adverse clinical outcomes.