Predictors of bloodstream infection and its impact on mortality in septic arthritis: A 15-year review.

Background: Septic arthritis is frequently complicated by bloodstream infection (BSI), which can lead to metastatic infections and sepsis. In the current study, we aimed to identify risk factors for septic arthritis-related BSI and assess its impact on clinical outcomes.

Methods: A retrospective review spanning 15 years (January 2009 to May 2023) was conducted on patients diagnosed with septic arthritis. Data from patients with positive synovial fluid cultures were analyzed.

Results: Among 456 patients with septic arthritis, 16.8 % (n = 77) developed BSI. The 90-day mortality rate was significantly higher in patients with BSI than in those without BSI (14.3 % vs. 5.3 %, p = 0.004). Staphylococcus aureus was the most commonly identified organism in synovial fluid cultures, and the presence of S. aureus infection was associated with an increased risk of BSI (adjusted odds ratio [aOR], 2.20; 95 % confidence interval [CI], 1.15-4.34; p = 0.019). Independent risk factors for BSI included a higher Sequential Organ Failure Assessment (SOFA) score (aOR, 1.23; 95 % CI, 1.06-1.44; p = 0.009), lymphopenia (aOR, 2.84; 95 % CI, 1.38-6.15; p = 0.006), and elevated C-reactive protein (mg/dL) levels (aOR, 1.07; 95 % CI, 1.05-1.10; p < 0.001). Age ≥70 years (aOR, 3.96; 95 % CI, 1.49-11.85; p = 0.009) and a higher SOFA score (aOR, 1.36; 95 % CI, 1.12-1.67; p = 0.002) were significant predictors of 90-day mortality, although BSI itself was not.

Conclusion: Mortality in patients with septic arthritis was primarily associated with systemic sepsis due to BSI rather than BSI itself. Understanding the relationship between septic arthritis-related BSI and clinical outcomes could aid physicians in managing systemic infections and improving patient care.