A New Scoring System to Predict Blood Stream Infections in Patients with Complicated Intra-Abdominal Infections: Experience from a Tertiary Referral Hospital in China

Background: This purpose of this study was to investigate the effects of blood stream infections (BSIs) on the prognosis of patients with complicated intra-abdominal infections (IAIs) and to make predictions based on patients' characteristics on admission. Patients and Methods: One hundred eighty-seven patients with complicated IAI in 2014 and 2015 were included in our retrospective analysis, except for those diagnosed with central line-associated blood stream infections (CLABSIs). Patients with BSIs were compared with patients without BSIs. Multivariable logistic regression was applied to identify factors associated with BSIs and also the subtypes of BSIs. The predictive score systems were established further. Results: Seventy-four patients (39.6%) with complicated IAIs developed BSIs after admission. Four factors evaluated on admission were associated independently with BSIs including alanine aminotransferase (ALT) >= 66 U/L (two scores), insensitivity to initial empirical antibiotic agents (IIEA; three scores), Sepsis-Related Organ Failure Assessment (SOFA) score of two or more (three scores), and generalized peritonitis (four scores). A total score of five or more was regarded as the critical value in the combined test to predict BSIs, with a sensitivity of 0.78 and a specificity of 0.73. Blood stream infections were further divided as secondary BSIs and non-secondary BSIs. The risk factors of secondary BSIs included IIEA (three scores), SOFA score of two or more (five scores), and generalized peritonitis (eight scores), where a total score of nine or more was regarded as the critical value in the combined test, with a sensitivity of 0.68 and a specificity of 0.87, whereas the risk factors of non-secondary BSIs included IIEA (three scores), SOFA score of two or more (three scores) and procalcitonin (PCT) >= 0.43 mcg/L (three scores), where a total score of six or more was regarded as the critical value in the combined test, with a sensitivity of 0.75 and a specificity of 0.70. Moreover, BSIs were linked with the worse clinical outcomes in organ functions, hospitalization costs, and mortality. Conclusions: Our new scoring methods may have potential advantages on the early prediction and recognition of BSIs in patients with complicated IAIs.