Impact on mortality of adherence to evidence-based interventions in patients with catheter-related bloodstream infection due to methicillin-sensitive Staphylococcus aureus.

BACKGROUND: Recent studies have demonstrated improved survival when the management of Staphylococcus aureus bloodstream infection (BSI) is compliant with evidence-based therapeutic interventions. Whether this effect extends to low-risk sources, such as catheter-related BSI, remains unclear.

METHODS: We retrospectively included 225 episodes of methicillin-sensitive S. aureus catheter-related BSI diagnosed in our centre during two non-consecutive periods: 2002-2004 (first period (101 episodes)) and 2009-2013 (second period (124 episodes)). We evaluated the adherence (percentage of compliance = (no. of interventions performed/no. of interventions recommended) × 100) to the following bundle: early catheter removal (≤72 hours), early initiation of appropriate antibiotic therapy, adequate sampling of follow-up blood cultures, transthoracic echocardiography (TTE) during hospitalization and adequate duration of therapy.

RESULTS: Patients in the second period had a higher burden of comorbidities and more severe underlying conditions. All-cause 30-day mortality was 9.3%, with a significant difference between the first and second periods (13.9% versus 5.6%; p value = .035). Bundle adherence was significantly higher in the second period, particularly for follow-up blood cultures (26.7% versus 48.4%; p value = .001), performance of TTE (45.5% versus 84.7%; p value < .001) and appropriate duration of therapy (34.7% versus 50.0%; p value = .022). Bundle adherence ≥ 55% was associated with lower 30-day mortality (hazard ratio: 0.31; 95% confidence interval: 0.13-0.76). This effect remained significant across propensity score-based models adjusted for septic shock, study period and underlying conditions.

CONCLUSIONS: There was a survival benefit in adhering to a bundle of evidence-based interventions in the specific setting of catheter-related BSI due to methicillin-sensitive S. aureus.