Evaluation of Risk Factors Causing Nosocomial Acinetobacter Bacteremia and Mortality in the Intensive Care Unit

Abstract

Objective: We aimed to evaluate risk factors for bacteremia and mortality in patients with nosocomial Acinetobacter bacteremia in a university hospital’s Anesthesia and Reanimation Intensive Care Unit (ICU) between 2013-2016. Methods: This study was designed as a retrospective case-control study; the case group consisted of patients older than 18 years, with Acinetobacter species growth in blood cultures taken 48 hours after hospitalization, with clinical bacteremia findings, followed until death or at least 30 days after culture. Patients in the control group consisted of cases without Acinetobacter bacteremia and showed similar characteristics to the case group. Patients were evaluated regarding demographic characteristics, underlying diseases, carbapenem use before blood culture was taken, appropriate empirical treatment, 30-day mortality, nutritional status, Pittsburgh Bacteremia Score (PBS), and interventional procedures. Results: Among case and control groups each consisting of 51 patients, carbapenem use (63.2% and 34.8%, respectively, odds ratio (OR)=3.67; 95% confidence interval (CI)=1.49-9.04, p=0.005) and chest tube placement (23.5% and 7.8%, respectively, OR=7.31; 95% CI=1.43-37.22, p=0.005) were independent risk factors for Acinetobacter bacteremia. Among cases with or without mortality in the case group, there was a significant difference in terms of endotracheal intubation (100%, 76.9%, respectively, p=0.023), PBS (6.6±1.08, 5.0±2.29, respectively, p=0.003), nutritional status (total parenteral nutrition [TPN] or enteral nutrition +TPN) (%28, %0 and %72, %100, respectively, p=0.004) and hypertension (HT) (%52, %19.2, respectively, p=0.03) and also HT [52% and 19.2%, respectively, OR=4.61; 95% CI=1.08-19.57, p=0.038], inappropriate empirical therapy [69.6% and 30.8%, respectively, OR=6.46; 95% CI=1.55-26.94, p=0.01] and albumin level [2.32±0.50 and 2.57±0.44 g/dL, respectively, OR=0.196; 95% CI=0.045-0.847, p=0.029] were independent mortality risk factors. Conclusion: Previous carbapenem use and chest tube insertion are important risk factors for Acinetobacter bacteremia in ICU. Inappropriate empirical treatment, HT, and low albumin levels are important mortality risk factors in Acinetobacter bacteremia in ICU. High PBS scores should be carefully evaluated for mortal Acinetobacter bacteremia.