Factors Associated with Improved Outcome of Pseudomonas aeruginosa Bacteremia in a Finnish University Hospital

Abstract

All 134 episodes of bacteremia caused solely by Pseudomonas aeruginosa in a university hospital in the periods 1976-1982 and 1992-1996 were reviewed retrospectively to determine the clinical manifestations, outcome and prognostic factors. The mortality for the 30-day interval after drawing the first positive blood culture was 41%, but dropped from 53% in the first period to 29% in the second period (P=0.006). Mortality was highest in patients treated with an aminoglycoside only, as against those treated with other appropriate antibiotics (55% versus 25%, P=0.001). Over the two decades studied, use of an aminoglycoside only decreased, use of paracetamol (=acetaminophen) increased, and removal of both urinary and blood vessel catheters became more common. The mortality was 18% in patients with catheter removal (46% in the other patients, P=0.017) and 27% in patients who received paracetamol around the time of drawing the first positive blood culture (50% for the other patients, P=0.010). Logistic regression analysis showed that shock, central nervous system involvement, preceding thromboembolism and rapidly fatal underlying disease were associated with a fatal outcome, whereas catheter removal, appropriate antibiotic therapy and paracetamol therapy were associated with survival. The improved prognosis of Pseudomonas aeruginosa bacteremia over the two decades is thus due mainly to three changes in management of the infection: the more frequent use of new anti-pseudomonal beta-lactams and ciprofloxacin instead of aminoglycosides as monotherapy; the more frequent practice of removing catheters; and the increased use of paracetamol around the time of drawing the first positive blood sample.

A clinical index predicting mortality with Pseudomonas aeruginosa bacteraemia

“…However, the present study, like other large series from the literature underlined the importance of nosocomial acquisition [2,[4][5][6][7][8][9][10][11]: 88% of our patients developed the infection in hospital. As in other series [3,4,11], preceding procedures and therapies were common in the patients in the present study, and are indicative of the number and severity of concomitant illnesses seen in these patients.…”

“…It is frequently hospital-acquired and may be polymicrobial in nature [1,2]. Despite all the advances in medical practice in recent years, pseudomonal bacteraemia continues to have a high associated mortality, ranging from 18% to 61% [2][3][4][5][6][7][8][9][10][11]. Therefore, investigators have attempted to define those factors that influence the outcome of this infection.…”

“…Therefore, investigators have attempted to define those factors that influence the outcome of this infection. These analyses have emphasised the deleterious impact of underlying diseases [3,8,10], septic shock [2,5,6,8,10,11] and the development of septic metastasis [2,5,6] on the outcome of bacteraemia. The availability of potent antimicrobial agents as well as high technology support for therapy of P. aeruginosa bacteraemia has barely modified the mortality rate [9].…”

Pseudomonas aeruginosa infections: factors relating to mortality with emphasis on resistance pattern and antimicrobial treatment

“…The factors that predict a fatal outcome vary among studies and include septic shock, pneumonia, advanced age, severity of the underlying disease, use of inappropriate antimicrobials and emergence of antimicrobial resistance during treatment [7][8][9][10][11]. Rello et al [12] estimated a mortality rate of 13.5% attributable to pneumonia associated with mechanical ventilation caused by P. aeruginosa.…”

Catheter-related bloodstream infections: catheter management according to pathogen

“…Hanna and colleagues [66] showed that documented CRBSIs caused by Gram-negative bacilli were associated with a high frequency of relapse if the CVC was retained. Similarly, with P. aeruginosa CVC sepsis catheter removal also improved patient outcome [67]. Failure to remove the catheter was associated with a significantly higher rate of treatment failure and bacteraemia recurrence (P <0001).…”