Introducing guidelines for surgical antibiotic prophylaxis - an impact assessment

Abstract

Prophylactic antibiotics in surgical patients aim at reducing the incidence of infections with as minimal an effect on the patient as possible. Risk of post-operative infection depends on both the surgical technique, type of surgery and patient's condition. Antibiotic prophylaxis is administered when the risk of contamination is high or when the potential consequences of infection though rare are very serious. This study was aimed at evaluating the situation at Malta's general hospital with respect to antibiotic prophylaxis. One objective of the questinnaire study was Lo assess The knowledge on antibiotic prophylaxis by means of a questionnaire disseminated to all senior surgical staff, anaesthetists and dentists, concurrently with the publication of local guidelines. Another objective was to assess the impact the guidelines would have on: choice of prophylactic antibiotic, if any; timing of administration, and; duration of surgical antibiotic prophylaxis. An audit was carried out before and after the launch the guidelines in all surgical wards of St Luke's Hospital. The questionnaire had a response rate of 48.4%. The great majority of respondents (96.7%) could define surgical antibiotic prophylaxis. The correct definition of 'timing of administration' and 'duration of antibiotic prophylaxis' was lower at 82.3% and 66.1 % respectively. Another issue identified was the lack of self-audit of surgical infections.

In the audit study the number of cases where antimicrobial prophylaxis was indicated were, 177/285 (62%) in survey-1 (pre guideline) and 200/304 (66%) in survey-2 (post guideline) respectively (p = 0.1762). The audit showed a significant improvement in appropriate antimicrobial selection, when utilised [221 cases (77.5%, Survey-1) - 219 cases (72.0%, Survey-2)] {50.2% to 77.6%, p <0.0001}. Hundred-eleven cases in survey-1 and 169 in survey-2 were evaluated for 'timing of administration'. Eighty cases (72.1 %) from survey-1 and 140 (82.8%) from survey-2 had an 'acceptable timing'. This had a significant increase from 72.1 % to 82.8% (p - 0.01578). The net acceptable duration of antimicrobial prophylaxis was 20/80 (25.0%) in survey-1 and 38/140 (27 1%) in survey-2 (p=0.3632) These changes in duration were not significant. Single interventions, such as publishing guidelines, alone are not as effective as rnultiple interventions. Therefore, educational circulars/rnernos (to act as reminders) and workshops (with continuous medical education accreditation to enhance participation) are recommended. Furthermore, 'antibiotic prophylaxis automatic stop dates' aiming to reduce unnecessary long duration of use and 'audit and feedback' to instigate self-monitoring and improvement should also be introduced. Finally, two more potentially controversial recommendations are: a] more involvement of the anaesthetist in antibiotic prophylaxis in order to avoid having the prophylactic antibiotic written on the patients' treatment chart, therefore avoiding prolonged duration of prophylaxis and b] clinical pharmacists on the surgical wards who review any treatment prescribed.