Surgical antimicrobial prophylaxis in open reduction internal fixation procedures at a metropolitan hospital in Australia: a retrospective audit

Background: Open reduction internal fixation (ORIF) of closed fractures is a required indication for surgical antimicrobial prophylaxis (SAP). Guidelines contain recommendations on how best to prescribe SAP, however, adherence to SAP guidelines remains suboptimal. The Australian Therapeutic Guidelines: Antibiotic v16 (updated April 2019) advocates for single dose prophylaxis for ORIF procedures. There is a paucity of information on how SAP is prescribed for ORIF of closed fractures in Australian hospitals. The aim of this study was to identify prescribing practice and to evaluate guideline adherence pre- and post-guideline update. Methods: A retrospective audit was conducted for patients undergoing an ORIF of closed fractures at a metropolitan teaching hospital in a 6-month period during 2018 (pre-guideline update) and 2019 (post-guideline update). Data were collected on prescribing practice (perioperative antibiotics prescribed, dose, time and route of administration and duration of prophylaxis) and compared to SAP recommendations in Therapeutic Guidelines: Antibiotic v15 (2018) and v16 (2019). Descriptive statistics and Chi square tests were used to report categorical variables. Binary logistic regression was used to identify factors associated with guideline adherence. A p-value < 0.05 was deemed statistically significant. Results: Data were collected for a total of 390 patients (n = 185, 2018; n = 205, 2019). Cefazolin was the most commonly prescribed antibiotic as per guideline recommendations, with variable, yet appropriate doses observed across the two audit periods. While 78.3% of patients received SAP for the correct duration in 2018, only 20.4% of patients received single dose prophylaxis in 2019. Overall adherence to guidelines was 63.2% in the 2018, and 18.0% in the 2019 audit periods respectively. Patient age was significantly associated with an increase in overall guideline adherence, while lower limb fractures, an American Society of Anesthesiologists