Characteristics of Pseudomonas aeruginosa infection in intensive care unit before (2007–2010) and after (2011–2014) the beginning of an antimicrobial stewardship program

Abstract

Abstract Objectives: To investigate the factors associated with Pseudomonas aeruginosa isolates in intensive care unit (ICU) before and after an antimicrobial stewardship program. Materials: Monocentric retrospective cohort study. Patients admitted to the ICU in 2007–2014 were included. Characteristics of P. aeruginosa patients were compared to overall ICU population. Clinical and microbiological characteristics of P. aeruginosa patients before (2007–2010) and after (2011–2014) the beginning of the AMP were compared. Results: Overall, 5,263 patients were admitted to the ICU, 274/5,263 (5%) had a P. aeruginosa isolate during their staying. In 2011–2014, the percentage P. aeruginosa isolates reduced (7% vs 4%, P ≤ .0001). Patients with P. aeruginosa had higher rates of in-hospital death (43% vs 20%, P < .0001) than overall ICU population. In 2011–2014, rates of multidrug-resistant (11% vs 2%, P = .0020), fluoroquinolone-resistant (35% vs 12%, P < .0001), and ceftazidime-resistant (23% vs 8%, P = .0009) P. aeruginosa reduced. Treatments by fluoroquinolones (36% vs 4%, P ≤ .0001), carbapenems (27% vs 9%, P = .0002), and third-generation cephalosporins (49% vs 12%, P ≤ .0001) before P. aeruginosa isolation reduced while piperacillin (0% vs 13%, P < .0001) and trimethoprim-sulfamethoxazole (8% vs 26%, P = .0023) increased. Endotracheal intubation reduced in 2011–2014 (61% vs 35%, P < .0001). Fluoroquinolone-resistance was higher in patients who received endotracheal intubation (29% vs 17%, P = .0197). Previous treatment by fluoroquinolones (OR = 2.94, P = .0020) and study period (2007–2010) (OR = 2.07, P = .0462) were the factors associated with fluoroquinolone-resistance at the multivariate analysis. Conclusions: Antibiotic susceptibility in P. aeruginosa isolates was restored after the reduction of endotracheal intubation, fluoroquinolones, carbapenems, and third-generation cephalosporins and the increased use of molecules with a low ecological footprint, as piperacillin and trimethoprim-sulfamethoxazole.