Factors Related to Mortality in Carbapenem Resistant Acinetobacter baumannii Infections in Intensive Care Units: A Prospective Observational Study

Abstract

Introduction: Management of carbapenem resistant Acinetobacter baumannii infections in intensive care units is challenging because of few treatment options and poor outcomes. In order to contribute to patients’ survival, the factors related to mortality in these infections were evaluated in this study. Materials and Methods: In the 6-month study period, we included 60 patients with carbapenem resistant A. baumannii infections (45 ventilator associated pneumonia and 15 bacteremia) in two intensive care units of our hospital. We collected data of the patients prospectively. We noted demographic features of patients, Acute Physiology and Chronic Health Evaluation (APACHE II) , Sequential Organ Failure Assessment (SOFA), Clinical Pulmonary Infection Score (CPIS), Acute Kidney Injury (AKIN) scores, antibiotic treatments, clinical and microbiological outputs, and mortality rates during treatment and on the 30th day. Results: We observed that infections appeared at mean 11th day of the patients’ stay in the intensive care unit. Carbapenem resistant A. baumannii isolates were highly resistant to antibiotics except colistin. Only 9% of the patients had proper empirical treatment. Twenty five percent of the patients were dead before having a specific antibiotic treatment. Crude mortality rate was 66.7%, and 30th day mortality was 71.7%. The patients who had colistin and tigecycline combination had higher survival rates, but it was statistically insignificant. In univariate analysis high SOFA score (p= 0.0001), high procalcitonin level (p= 0.01), septic shock (p= 0.005), renal insufficiency (p= 0.005), rheumatological disease (p= 0.03) were related to higher mortality. We detected high SOFA score on the first day of infection as the only mortality related factor in multivariate analysis (p= 0.012). The patients who had higher mortality were those with delayed (> 3 days) proper antimicrobial treatment (p= 0.03). Conclusion: In our study, the high SOFA score on the first day of infection in intensive care units was found as a risk factor for mortality. We suggest that prompt administration of the proper antibiotic treatment to the patients who have risk factors for carbapenem-resistant A. baumannii infection can contribute to survival.