Clinical characteristics, risk factors, and mortality associated with Pseudomonas aeruginosa bacteremia

Abstract

Introduction: Pseudomonas aeruginosa bacteremia (PAB) is a major cause of morbidity and mortality, increasingly complicated by multidrug-resistant (MDR) strains which becomes a challenge to the treating physician. This study aimed to evaluate risk factors associated with PAB and its outcomes.

Methodology: A retrospective cohort study was conducted at the American University of Beirut Medical Center (AUBMC), including 85 patients who were > 18 years of age with confirmed PAB during their hospital stay between 2017 and 2022.

Results: Regarding resistance patterns, 8 (9.4%) patients had MDR strains and 19 (22.4%) were difficult to treat (DTR). Prior antibiotic use within 1 month was associated with the DTR infections (OR 4.97; p = 0.026). The in-hospital mortality rate was 51.8%. Male gender was associated with decreased mortality (OR 0.13; p = 0.036). Recent central line placement and Pitt bacteremia score were linked to increased mortality (OR 2.63; p = 0.028 and OR 51.71; p < 0.001, respectively). High-risk primary sources of infection such as central line, gastrointestinal, and respiratory systems had increased mortality compared with low-risk sources such as skin, abscess, and urinary tract (OR 25.96; p = 0.001).

Conclusions: Prompt empirical therapy and identifying the infection source are critical in assessing severity of the infection in PAB. Pitt bacteremia score is a valuable predictor of outcomes. Rising DTR rates was linked to prior antibiotic use which highlights the importance of antimicrobial stewardship.