141. SEPTIC ARTHRITIS: AUDIT OF CURRENT PRACTICE AT UNIVERSITY COLLEGE LONDON HOSPITAL

Abstract

Background: There is a wide differential in the diagnosis of a hot, swollen joint. Septic arthritis must be ruled out since delayed or inadequate treatment can lead to permanent joint damage. We conducted an audit of patients with septic arthritis presenting to an acute NHS hospital, recognizing a current lack of consensus around admitting team, preferred imaging modalities and overall management. Variation in practice was assessed, and comparisons made with national guidelines. Methods: Twenty-two patients with a diagnosis of native joint septic arthritis admitted to UCLH from January 2014 to May 2015 were identified from local databases. Length of admission, admitting team, investigations and invasive procedures performed, antimicrobial choice and duration was recorded, and the data were compared with local and national guidelines. Results: Ten patients were admitted under Orthopaedics, four under Infectious Diseases and four under Rheumatology. Paediatrics and Gynaecology admitted two patients each. Length of admission ranged from 4 to 34 days (median 14 days). All patients had appropriate admission bloods and almost three quarters had blood cultures drawn prior to initial antibiotic dose. Nearly all patients underwent some form of imaging. X-ray and MRI were the preferred modalities, despite current guidelines emphasizing the limited role of the latter. Ultrasound was employed in all patients admitted under Rheumatology. In five patients, no aspiration or washout was performed but where this did occur, Gram stain of the fluid was performed in all cases. Current guidelines recommend processing joint aspirate samples for glucose, LDH and lactate levels, but these were not requested in any of the patient cohort. An organism was isolated in 12 cases. Staphylococcus aureus was the most frequently identified, and choice of antibiotic was appropriate in the majority of patients. Intravenous flucloxacillin, teicoplanin and clindamycin were commonly used first line drugs. Duration of antibiotic therapy was inconsistent but the average length of IV treatment was 11.6 days, followed by 26 days of oral therapy. This falls short of the six weeks recommended in current guidelines. Conclusion: Generally, simple procedures such as blood tests and cultures were appropriately requested for all patients admitted with suspected septic arthritis. Further investigation was extensive and robust in most cases, if not entirely in keeping with current guidelines. Updated, evidence-based guidelines are needed to promote optimal management of septic arthritis. Antimicrobial treatment, particularly regarding duration of therapy, remains unstandardized and further research data would inform current practice. This audit will help to shape future hospital policy, assist in assessing treatment outcomes, ensure greater consistency in practice and highlight research questions.