1478. A Retrospective Review of Pseudomonas aeruginosa Infection in a Quarternary Intensive Care Unit: Epidemiology, Outcomes, and Antimicrobial Susceptibilities: 2013–2016

BACKGROUND: Pseudomonas aeruginosa (PA) is known to cause infection in the intensive care unit (ICU) and contribute to substantial morbidity and mortality. The objectives of this study were to describe the epidemiology, antimicrobial resistance and outcomes in critically ill patients with pseudomonal infection. METHODS: Patients with PA isolated during ICU admission from 2013–2016 were identified using provincial microbiology data. Patients were classified as colonized or infected. Those with infection were reviewed for source of infection, patient characteristics, antimicrobial susceptibilities, appropriateness of empiric antimicrobial therapy and 30-day mortality. Independent predictors of mortality were identified using multivariable logistic regression. RESULTS: A total of 196 unique patients were culture-positive for PA. 140 (71%) were infected and included for analysis. Mean patient age was 55.4 years (18.4 SD) and 62% were male. Admission categories included medical (71%), surgical (20%), and trauma or neurological (9%). Mean APACHE II score at the time of ICU admission was 19.4 (9.8 SD). One hundred and twenty-six (90%) patients required invasive mechanical ventilation, 102 (73%) vasopressor support and 27 (19%) new initiation of renal replacement therapy. Thirty-two (23%) died within 30 days of ICU admission. The median ICU length of stay was 13 days (IQR 5–27). Median time to infection was 1 day (IQR 0–9). Sources were respiratory (66%) followed by skin/soft tissue (11%), urinary (10%), and blood (5%). Twenty (14%) isolates were multi-drug-resistant (MDR) and six (4%) were extensively drug resistant (XDR). There were no pan-resistant isolates. One hundred and one (52%) of infections were nosocomial. Empiric antimicrobial therapy was effective in 97 (69%) cases. On multivariable analysis liver disease (aOR 6.2, 95% CI 1.5–25.7; P = 0.01), malignancy (aOR 5.0, 95% CI 1.5–17.3; P = −0.01) and higher APACHE II score at the time of admission (aOR 1.1, 95% CI 1.0–1.1; P = 0.02), were independently associated with 30-day mortality. CONCLUSION: PA in the ICU is associated with substantial mortality and is most commonly isolated from the respiratory tract. Existing malignancy, liver disease and higher APACHE II score at admission were independently associated with mortality. DISCLOSURES: All authors: No reported disclosures.