[Adequacy of the consumption of antipseudomonal antibiotics after changes in the 2019 EUCAST criteria]

OBJECTIVE

In 2019, the European Committee for the Study of Antibiotic Susceptibility modified the categories of antibiotic susceptibility tests to include the term "susceptible with increased exposure". Following the dissemination of local protocols reflecting these modifications, the aim of our study was to analyse whether prescribers have adapted to them and the clinical impact in cases of inadequacy.

METHODS

Observational and retrospective study of patients with infection who received antipseudomonal antibiotics from January to October 2021 in a tertiary hospital.

RESULTS

Non-adherence to the guideline recommendations was 57.6% in the ward and 40.4% in the ICU (p<0.05). In both the ward and ICU, the group with the most prescriptions not by the guideline recommendations were aminoglycosides (92.9% and 64.9% respectively) for using suboptimal doses, followed by carbapenems (89.1% and 53.7% respectively) for not administering an extended infusion. On the ward, the mortality rate during admission or at 30 days in the inadequate therapy group was 23.3% vs 11.5% in those who received adequate treatment (OR: 2.34; 95% CI 1.14-4.82); in ICU there were no statistically significant differences.

CONCLUSIONS

The results show the need to implement measures to ensure better dissemination and knowledge of key concepts in antibiotic management, to ensure increased exposures, and to be able to provide better infection coverage, as well as to avoid amplifying resistant strains.

[Utilization study in real clinical practice of ceftolozane/tazobactam vs aminoglycosides and/or colistin in the treatment of multirresistant or extremely resistant Pseudomonas aeruginosa]

OBJECTIVE

Comparative "real life" data on the effectiveness and safety of ceftolozane/tazobactam (C/T) versus other regimens (aminoglycosides/colistin/combination), in the treatment of multi-resistant (MDR) and extremely resistant (XDR) Pseudomonas aeruginosa (PA), are needed to establish positions.

METHODS

Observational, retrospective study of patients with microbiological confirmation of MDR and XDR PA from July 2016 up to December 2018 in a tertiary hospital. Variables: age, sex, comorbidities, risk factors for multidrug resistance, variables related to infection, source of infection, microorganism and type of sample, antibiotic treatment, clinical cure, microbiological cure, recurrence, mortality on admission and 30 days post-discharge. Patients were classified according to received antibiotic treatment, C/T or aminoglycosides/colistin/combination.

RESULTS

A total of 405 patients with PA MDR and XDR infection (73.1% men, mean age 63 ± 15 years) were studied. An 87.1% of PA XDR and a 12.9% MDR were observed. All patients received C/T as targeted therapy and in the aminoglycosides/colistin/combination group were 73.5%. Patients in the C/T group present worse prognostic factors: septic shock (30.0%) and catheterization (90.0%) (p<0.05). There were not statistically significant differences in microbiological cure (p=0.412), recurrence (p=0.880) and clinical cure (p=0.566). There were not statistically significant differences in mortality at admission (p=0.352) or at 30 days after discharge (p=0.231). A 17.2% of the patients with aminoglycosides/colistin/combination had acute kidney injury according to RIFLE criteria and 4.3% with C/T.

CONCLUSIONS

The data obtained suggest that there have been no differences in effectiveness (clinical or microbiological cure) in favour of C/T, although, in the period studied, it was used in most cases in multitreated patients with a worse prognosis. Randomized and prospective studies would be needed to establish an adequate positioning.