Background Epidemiological studies have shown an association between antibiotic consumption and the emergence of resistance. Clinical results depend on the host, the organism and an appropriate treatment. Institutional antibiotic use policies have an important role in reducing the selective pressure for resistance, improving the quality of outcomes and patient safety.

Purpose To analyse the impact of a stewardship programme focused on the appropriateness of antibiotic treatment for the treatment of intra-abdominal infections (IAI).

Material and methods A pre-post intervention study was undertaken during October–November 2013 (“PRE” period) and January–February 2014 (“POST” period). General Surgery patients on active antibiotic treatment were included, excluding prophylactic antibiotics administered preoperatively. The variables analysed were:

1. Demographics: age, sex, comorbidities and risk factors for extended-spectrum beta-lactamase (ESBL)-producing Enterobacteria.

2. Suitability of treatments: inappropriate treatment was defined as: excessive length, incorrect dose and/or route of administration, and the use of a broad-spectrum antibiotic when de-escalation was possible in targeted treatment.

3. Consumption: Defined Daily Dose (DDD)/100 bed-days).

Data was extracted from blood tests, clinical records and microbial culture records.

Results PRE study: n = 74 (60% male); mean age 60 years, average treatment length 7 days, length of stay 4.9 days and overall consumption 75.9 DDD/100 bed-stays. In 59% no cultures were performed. IAI type: complicated 26% vs. 74% non-complicated. Of 111 total treatments, 84% were empirical and 20% were inappropriate.

POST study: n = 57 (50% male), mean age 57 years, average treatment length 9 days and length of stay 5.1 days. The overall consumption was 80.1 DDD/100 day-stays. In 50% cultures were not requested. IAI type: complicated 32% vs. 68% non-complicated. Of 76 total treatments, 78% were empirical. In 20% of the cases, a pharmaceutical intervention was performed, of which 75% were accepted, eventually resulting in 11% inappropriate treatments.

Antibiotic prescription patterns had changed during the POST-period. There was a reduction in overall carbapenem use with an increased narrow-spectrum prescription (DDD-100 bed-days): amoxicillin-clavulanate (37.3 vs. 32.6); piperacillin-tazobactam (2.7 vs. 1.6), ciprofloxacin (7.6 vs. 6.9) and metronidazole (4.7 vs. 4.3). Carbapenems consumption went down to 15.2 DDD/100 bed-days in the post-period vs. 18.5 DDD/100 bed-days in the Pre-period.

Conclusion

• Use of broad-spectrum antibiotics is reduced and de-escalating has been promoted.

• Taking samples prior to initiation of antibiotic treatment is encouraged.

• The increased treatment length (26%) was probably due to more serious infections.

• The multidisciplinary approach is one of the main tools of optimisation-antimicrobial-use-programs.

References and/or Acknowledgements

1. The PAMACTA team

References and/or AcknowledgementsNo conflict of interest.