Clinical characteristics and risk factors for mortality in patients with bacteremia caused by Pseudomonas aeruginosa.

OBJECTIVE: The mortality rates for bacteremia due to Pseudomonas aeruginosa remain high. In our hospital, we performed retrospective analyses to determine risk factors for mortality among patients with bacteremia caused by P. aeruginosa.
MATERIALS AND METHODS: This retrospective cohort study was conducted among adult patients with bacteremia due to P. aeruginosa at Jikei University Hospital. We analyzed factors, such as age, gender, underlying disease, initial antimicrobial treatment, and primary site of infection to determine which of these were predictive of mortality in patients with P. aeruginosa bacteremia.
RESULTS: One hundred and thirty-four patients with P. aeruginosa bacteremia were identified between April 2003 and March 2010. The 30-day mortality rate among all patients with P. aeruginosa bacteremia was 20.9%. The most common underlying disease was leukemia (20.9%), and the most common primary site of infection was the urinary tract (24.6%). Seventy-one patients (65.7%) were treated with an appropriate initial antimicrobial regimen for P. aeruginosa bacteremia. However, these patients had similar 30-day mortality to that observed in patients not administered appropriate antibiotics. This study revealed that risk factors for the 30-day mortality were thrombocytopenia and polymicrobial P. aeruginosa bacteremia (p<0.01).
CONCLUSION: Thrombocytopenia and polymicrobial bacteremia were associated with a greater incidence of 30-day mortality among patients with P. aeruginosa bacteremia. On the other hand, age, underlying disease, and inappropriate initial empirical antimicrobial treatment did not affect mortality.