Background The management of infection by Pseudomonas aeruginosa (PA) is complicated. PA is a microorganism with intrinsic resistance to many antibiotics, with increasing resistance to agents that are currently considered therapeutic options.

Purpose Analysing antimicrobial therapy prescribed for the treatment of bacteremia PA at our centre.

Material and methods Retrospective observational study conducted/completed from January 2011 to December 2014. Inclusion criteria: patients with positive blood culture for PA. Treatment related variables were analysed. The adequacy of treatment was evaluated according to the antimicrobial guide from our hospital.

Results 67 episodes of bacteraemia were identified. The MDR-PA was isolated in 13.5% (n = 9). 161 prescriptions were performed. Antibiotics per patient average: 2.4. Combination therapy: 47.8% (n = 32) versus monotherapy: 52.2% (n = 35). Empirical prescriptions: 48% (n = 77) versus directed prescriptions: 52% (n = 84). Appropriate empirical prescriptions 83% (n = 52). Appropriate directed prescriptions: 92% (n = 60). Overall, appropriate prescriptions were 87% (n = 140). Main reasons for inadequacy: not sensitive germ 70% (n = 14), wrong dose 15% (n = 3). Antibiotics prescribed groups were: 25% quinolones, 24% beta-lactams+beta-lactamase inhibitors, 22% carbapenems, 19% aminoglycosides, 9% cephalosporins, 2% other. The antibiotics used to treat PA bacteraemia were pieracilina-tazobactam 22.9% (n = 37), ciprofloxacin 16.2% (n = 26), imipenem 13.1% (n = 21), amikacin 12.5% (n = 20), meropenem 9.4% (n = 15), levofloxacin 8.7% (n = 14), ceftazidime 6.8% (n = 11), gentamicin 3.8% (n = 6), tobramycin 2.4% (n = 4), cefepime 1.8% (n = 3), colistina 1.2% (n = 2), other 1.2% (n = 2). Only a few patients (5% (n = 3)) were allergic to any anti-pseudomonal antibiotic.

Conclusion

1. The monotherapy and combination therapy was used with similar frequency.

2. The rate of appropriate treatment was high, especially in targeted therapies.

3. The groups of antibiotics used were mainly quinolones, beta-lactams+beta-lactamase inhibitors and carbapenems, with piperacillin-tazobactam, ciprofloxacin and imipenem the most commonly used antibiotics.

4. Due to the low incidence of resistances and patients allergic to anti-pseudomonal antibiotics, it is unlikely that these conditions influence the pattern of prescribing antibiotics.

5. Due to these results, the antibiotic stewardship group will consider training sessions to encourage prescribing anti-pseudomonal cephalosporins.

ConclusionNo conflict of interest.