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.