Written by Laura Murphy
Spoon Feed
Preoperative antibiotics significantly decreased the microbiologic yield of operative cultures (10.9%) in patients with native joint septic arthritis.
Pre-op antibiotics – let’s not miss the big picture…
This study explored the relationship between preoperatively administered antibiotic therapy on microbiologic yield of operative cultures for diagnosis, and is the first adult study restricted to native joint septic arthritis (NJSA). This retrospective cohort study was a paired analysis of preoperative aspirate (POC) and operative cultures (OC), including 299 patients with NJSA affecting 321 joints in Mayo Clinic facilities in several states. Microbiologic yield decreased from 68.0% at POC to 57.1% in patients receiving preoperative antibiotics, and there was a nonsignificant increased yield (60.9% at POC to 67.4% at OC, P=0.244) in patients who did not receive preoperative antibiotics. Preoperative antibiotic exposure was more likely to decrease OC yield compared to non-exposure (OR=2.12; 95% CI=1.24-3.64; P=0.006). Duration of therapy and number of preceding doses also impacted yield. Authors noted that streptococcal organisms appear to be most affected by antibiotic administration. The results of this study aren’t surprising, and parallel findings in studies examining microbiologic yield from joint aspirate. While this adds important insight to a growing body of evidence, the authors do not advocate delaying empiric antibiotic treatment until after operative culture is obtained. While delay in therapy may increase diagnostic yield, this has to be balanced with the morbidity and mortality associated with delays. These are significant, especially when you consider that over 30% of these patients have concurrent bacteremia (46.2% in this study!), in which delay in antibiotic administration is known to be harmful.
How will this change my practice?
It won’t. Delaying treatment for patients with suspected septic arthritis until OR cultures can be obtained is too risky. This highlights the importance of obtaining early cultures in the ED (including blood cultures and joint aspirate). If these can be obtained in a reasonable time frame in a stable patient, it makes sense to defer antibiotics until after these samples have been obtained.
Source
Effect of Preoperative Antibiotic Therapy on Operative Culture Yield for Diagnosis of Native Joint Septic Arthritis. Clin Infect Dis. 2024 Oct 15;79(4):1062-1070. doi: 10.1093/cid/ciae136. PMID: 38466824
