Source Control in Pseudomonas aeruginosa Bloodstream Infections: An Overlooked Pillar in Reducing 30-Day All-Cause...

Appropriate antibiotic therapy is a key determinant of outcomes in Pseudomonas aeruginosa bloodstream infection (BSI), but the impact of adequate source control on prognosis has not been well defined in large cohorts.

We conducted a retrospective multicenter study including hospitalized patients with P. aeruginosa BSI across 14 Italian hospitals between January 2021 and December 2022.

Overall, 639 BSI episodes were analyzed. The most frequent sources were an unknown source (31.8%), central venous catheter BSI (22.5%), hospital-acquired/ventilator-associated pneumonia (20.3%), urinary tract infections (11.4%), and intra-abdominal infections (6.9%). Source control was required in 34.0% of cases and was achieved early and adequately in 49.3% of these. The 30-day all-cause mortality rate was 23.9%. Mortality was significantly lower in patients who received early adequate source control (6.5%) compared with those without early adequate source control (23.6%) or in whom it was deemed unnecessary (28.4%) (P < .0001). In multivariable analysis, age, corticosteroid therapy, and septic shock were independently associated with increased mortality, whereas prior P. aeruginosa colonization, early adequate source control, and appropriate antibiotic therapy were protective. A propensity score-matched analysis confirmed the association between early adequate source control and reduced 30-day mortality (adjusted hazard ratio 0.15; P = .0024).

Early adequate source control is a critical determinant of survival in P. aeruginosa BSI. Outcomes are optimized by a combined approach integrating timely source control with appropriate antibiotic therapy.