Mortality Risk Factors of Acinetobacter baumannii Infections in a Medical Intensive Care Unit: A 2-Year Survey

• Main Authors: Gülbin AYGENCEL, Murat DİZBAY, Melda TÜRKOĞLU
• Format: Article
• Language: English
• Published: Bilimsel Tip Yayinevi 2011-03-01
• Series: Flora Infeksiyon Hastalıkları ve Klinik Mikrobiyoloji Dergisi
• Subjects: Acinetobacter baumannii infection; Intensive care unit; Risk factors; Mortality
• Online Access: http://www.floradergisi.org/getFileContent.aspx?op=REDPDF&file_name=2011-16-1-023-031.pdf

Introduction: Acinetobacter baumannii is considered to be a nosocomial pathogen gradually becoming more important around the world and in Turkey, particularly for patients in intensive care units (ICUs). In this study, we endeavored to overview the general characteristics of the inpatients who were treated in our ICU and diagnosed with A. baumannii infection, and particularly to determine risk factors of patients with mortal A. baumannii infection. Materials and Methods: This retrospective study was conducted in the nine-bed medical ICU of a 900-bed tertiary university hospital and was designed to include a two-year period (April 2007-April 2009). Characteristics of the patients before their admission to ICU and during their stay were examined, and factors related to A. baumannii infection together with factors affecting mortality were determined. Results: One hundred and twenty-nine patients were included in the study. Mean age of the patients was 63.05 (± 17.28) years, and 59.7% of the patients were males. The majority of the patients were admitted to the ICU from both emergency service and internal medicine clinics due to respiratory failure or sepsis. Forty-seven point three percent of patients (47.3%) were immunosuppressive. One hundred and sixty-three A. baumannii isolates were identified in 129 patients. A. baumannii was mostly isolated from tracheal aspirate cultures (70.5%) followed by bloodstream or central catheter cultures (16%). On average, 89% of isolates were resistant to ciprofloxacin and 94.5% to imipenem. Seventy-three percent of patients (n= 108) were diagnosed as pneumonia or ventilator-associated pneumonia (VAP), 15% (n= 22) as bloodstream infection, 8.7% (n= 13) as skin/soft tissue infection, and 3.3% (n= 5) as urinary tract infection. Ninety-eight patients (76%) who were infected by A. baumannii died. Factors affecting mortality according to univariate analysis were listed roughly in terms of Acute Physiology Assessment and Chronic Health Evaluation (APACHE) II score, length of hospital stay before ICU, the clinic from which the patient was transferred to the ICU, applied invasive procedures (mechanical ventilation, catheters, dialysis, etc.), complications in the ICU, and antibiotics used previously. According to multivariate analysis, the most significant risk factors for mortality were application of invasive mechanical ventilation, sepsis in the ICU and admission from internal medicine clinics. Conclusion: Resistant A. baumannii infections are among the major medical challenges worldwide, in Turkey, and in our ICU. The mortality rate is high, and different risk factors affect the mortality rate in A. baumannii infections. According to our study, application of invasive mechanical ventilation, sepsis in the ICU and admission from internal medicine clinics were the major risk factors for mortality in our A. baumannii-infected ICU patients.