Predictors of mortality of Pseudomonas aeruginosa bacteraemia and the role of infectious diseases consultation and source control; a retrospective cohort study.

Purpose: To determine predictors of mortality among patients with Pseudomonas aeruginosa bacteraemia.

Methods: Retrospective study.

Setting: This study conducted at the Lausanne University Hospital, Switzerland included adult patients with P. aeruginosa bacteraemia from 2015 to 2021.

Results: During the study period, 278 episodes of P. aeruginosa bacteraemia were included. Twenty (7%) isolates were multidrug-resistant. The most common type of infection was low respiratory tract infection (58 episodes; 21%). Sepsis was present in the majority of episodes (152; 55%). Infectious diseases consultation within 48 h of bacteraemia onset was performed in 203 (73%) episodes. Appropriate antimicrobial treatment was administered within 48 h in 257 (92%) episodes. For most episodes (145; 52%), source control was considered necessary, with 93 (64%) of them undergoing such interventions within 48 h. The 14-day mortality was 15% (42 episodes). The Cox multivariable regression model showed that 14-day mortality was associated with sepsis (P 0.002; aHR 6.58, CI 1.95-22.16), and lower respiratory tract infection (P < 0.001; aHR 4.63, CI 1.78-12.06). Conversely, interventions performed within 48 h of bacteraemia onset, such as infectious diseases consultation (P 0.036; HR 0.51, CI 0.27-0.96), and source control (P 0.009; aHR 0.17, CI 0.47-0.64) were associated with improved outcome.

Conclusion: Our findings underscore the pivotal role of early infectious diseases consultation in recommending source control interventions and guiding antimicrobial treatment for patients with P. aeruginosa bacteraemia.