Clinical characteristics, risk factors, prognosis and immune status of secondary infection of sepsis: a retrospective observational study
Abstract Background: Secondary infection has a higher incidence in septic patients and affects clinical outcomes. This study aims to investigate the clinical characteristics, risk factors, prognosis and immune status of secondary infection of sepsis. Methods: A four-year retrospective study was carried out in Zhongshan Hospital, Fudan University, enrolling septic patients admitted between January, 2014 and January, 2018. Clinical data were acquired from medical records. CD14+ monocyte human leukocyte antigen-D related (HLA-DR) expression and serum cytokines levels were measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA) respectively. Results: A total of 297 septic patients were enrolled, 92 of whom developed 150 cases of secondary infections. Respiratory tract was the most common site of secondary infection (n = 84, 56%) and Acinetobacter baumanii the most commonly isolated pathogen (n = 40, 31%). Urinary and deep venous catheterization increased the risk of secondary infection development. Lower HLA-DR expression and elevated IL-10 level were found in secondary infection group. The expected prolonged in-hospital stay owing to secondary infection was 4.63 days. Secondary infection was also associated with higher in-hospital, 30-day and 90-day mortality. Kaplan-Meier survival curves and Log-rank test revealed secondary infection group had a worse survival between day 15 and day 90. Conclusions: Urinary and deep venous catheter indwelling increased the risk of developing secondary infection. Secondary infection influenced outcomes of septic patients and prolonged in-hospital length of stay. Underlying immunosuppression led to a higher tendency to developing secondary infection.