Clinical Characteristics, Risk Factors and Mortality Associated with <i>Pseudomonas </i><i>Aeruginosa</i> Bacteremia

Pseudomonas aeruginosa bacteremia has become increasingly recognized as a major cause of morbidity and mortality and represents a challenge to the treating physician with the rise of multi-drug resistant (MDR) Pseudomonas. The purpose of this study is to evaluate the risk factors associated with Pseudomonas aeruginosa bacteremia and its clinical out-comes. A retrospective cohort study at the American University of Beirut Medical Center (AUBMC) was performed. It included 85 patients &gt; 18 years of age who had confirmed Pseudomonas aeruginosa bacteremia during their hospital stay from 2017 to 2022. With regard to resistance patterns, 8 (9.4%) were considered multidrug-resistant (MDR) and 19 (22.4%) were considered difficult to treat (DTR). Antibiotic use in the month preceding the infection was associated with the risk of DTR Pseudomonas infections (odds ratio 4.97; p-value 0.026). The in-hospital mortality rate was 51.8%. Male sex was associated with decreased mortality (odds ratio 0.13; p-value 0.036). Recent central line placement and Pitt bacteremia score were associated with increased mortality (odds ratios 2.63; p-value 0.028 and 51.71; p-value &lt; 0.001, respectively). Patients with high-risk primary sources of in-fection such as central line, gastrointestinal, and respiratory sources had increased mortality when compared to those with low-risk sources such as skin, abscess, and urinary sources (odds ratio of 25.96; p-value 0.001). In Pseudomonas aeruginosa bacteremia, in addition to prompt empirical treatment, identifying the primary source of infection is imperative as it can estimate the severity of the curent infection. Pitt bacteremia score can be an effective tool to evaluate patient outcome. Increasing antibiotic use has led to in-creasing rates of DTR Pseudomonas infections, which highlights the importance of an-timicrobial stewardship.