BackgroundWe investigated the possible role of the immune profile at ICU admission, among other well characterized clinical and laboratory predictors of unfavorable outcome in COVID-19 patients assisted in ICU.MethodsRetrospective analysis of clinical and laboratory data collected for all consecutive patients admitted to the ICUs of the General Hospital of Pescara (Abruzzo, Italy), between 1stMarch 2020 and 30thApril 2021, with a confirmed diagnosis of COVID-19 respiratory failure. Logistic regressions were used to identify independent predictors of bacteremia and mortality.ResultsOut of 431 patients included in the study, bacteremia was present inN= 191 (44.3%) and death occurred inN= 210 (48.7%). After multivariate analysis, increased risk of bacteremia was found for viral reactivation (OR = 3.28; 95% CI:1.83–6.08), pronation (3.36; 2.12–5.37) and orotracheal intubation (2.51; 1.58–4.02). Increased mortality was found for bacteremia (2.05; 1.31–3.22), viral reactivation (2.29; 1.29–4.19) and lymphocytes < 0.6 × 103c/µL (2.32; 1.49–3.64).ConclusionsWe found that viral reactivation, mostly due to Herpesviridae, was associated with increased risk of both bacteremia and mortality. In addition, pronation and intubation are strong predictors of bacteremia, which in turn together with severe lymphocytopenia due to SARS-CoV2 was associated with increased mortality. Most episodes of bacteremia, even due to Acinetobacter spp, were not predicted by microbiological evidence of colonization.