Investigating the Use of Routine Swabs in Incision and Drainage of Abscesses: An Audit of Western Sydney Hospitals

BACKGROUND: Incision and drainage of subcutaneous abscesses is a common surgical procedure. It is the standard of treatment, with or without adjunctive antibiotics. Interestingly, there exists a lack of evidence regarding the role of intraoperative sampling of the purulent discharge from abscesses. This study aimed to demonstrate whether intraoperative swab results were used to tailor antibiotic management and the circumstances surrounding these decisions. This will guide local practice for judicious collection of swabs and empirical antibiotic management. This is needed in the Western Sydney population, who are often co-morbid and experience recurrent abscesses. METHODS: A retrospective cohort study was performed of Westmead and Auburn Hospital's incision and drainage surgeries of subcutaneous abscesses from 2023 to 2025. RESULTS: A total of 2088 cases were identified and, in most cases (87%), an intraoperative swab was collected. The common causative organisms were staphylococcus, followed by streptococcus. Most organisms were pan-sensitive; however, of the multi-drug-resistant organisms, methicillin-resistant Staphylococcus aureus (MRSA) was most common. In 25% of cases where a causative organism was isolated, the bacteria were resistant to the antibiotic prescribed. However, the swab result only changed antibiotic management in 69 cases (3%). MRSA accounted for 62 of the 69 cases. Additionally, patients with causative organisms isolated were more often febrile (21%) than those without such swab results (16%) (p < 0.01). CONCLUSION: Overall, intraoperative swabs are recommended to be performed only in specific cases, not routinely. This includes patients who are febrile and patients with a history of or risk factors for multi-drug-resistant organisms such as MRSA.