Multi-drug resistance and other predictors for mortality in severe sepsis and sepsis chock due to Gram-negative and Gram-positive pathogens in a tertiary care hospital in Brazil: a retrospective matched case vs case vs control study design

Abstract

Introduction: Infections, mainly bloodstream infections (BSI), acquired in the intensive care unit (ICU) are associated with significant rates of morbidity and mortality, especially when caused by pathogens. The objectives the study were to determine risk factors and mortality rates in 30 days for patients with BSI caused by microorganisms resistant versus microorganisms susceptible to antimicrobials. Methods: A case-vs-control study was carried out, in which patients were identified with BSI acquired in the ICU. Control patients were paired, considering: age, acute mean severity classification (ASIS), and chronic disease scores, Charlson's Comorbidity Index (CHARLSON) both ≥ 3. Results: Retrospective cohort study of 531 patients, 254 with bloodstream infection (BSI), and 277 uninfected controls during hospital stay. Of those infected, 181 presented multidrug-resistant isolates (MDR) and 73, isolates susceptible to antibiotics. The univariate analysis showed statistically significant frequencies for BSIs, when compared with controls, of isolates resistant to multiple drugs and susceptible. There was also significance in the mortality rate among patients with resistant and susceptible pathogens (40.3% vs 34.2%, P<0.05). Multivariate analysis showed that only trauma and previous use of antibiotics were independent risk factors for BSIs in critically ill patients with infection, both by MDR and antibiotic-sensitive isolates. Conclusion: Mortality and bacteremia were higher in BSIs due to antibiotic-resistant isolates in a cohort of intensive care patients. The lack of financial and human resources results in multiple barriers in developing countries like Brazil and the prevention of these infections becomes a major challenge.