Management practices and major infections after cardiac surgery

Abstract

Background: Infections are the most common noncardiac complication after cardiac surgery, but their incidence across a broad range of operations, as well as the management factors that shape infection risk, remain unknown.

Objectives: This study sought to prospectively examine the frequency of post-operative infections and associated mortality, and modifiable management practices predictive of infections within 65 days from cardiac surgery.

Methods: This study enrolled 5,158 patients and analyzed independently adjudicated infections using a competing risk model (with death as the competing event).

Results: Nearly 5% of patients experienced major infections. Baseline characteristics associated with increased infection risk included chronic lung disease (hazard ratio [HR]: 1.66; 95% confidence interval [CI]: 1.21 to 2.26), heart failure (HR: 1.47; 95% CI: 1.11 to 1.95), and longer surgery (HR: 1.31; 95% CI: 1.21 to 1.41). Practices associated with reduced infection risk included prophylaxis with second-generation cephalosporins (HR: 0.70; 95% CI: 0.52 to 0.94), whereas post-operative antibiotic duration >48 h (HR: 1.92; 95% CI: 1.28 to 2.88), stress hyperglycemia (HR: 1.32; 95% CI: 1.01 to 1.73); intubation time of 24 to 48 h (HR: 1.49; 95% CI: 1.04 to 2.14); and ventilation >48 h (HR: 2.45; 95% CI: 1.66 to 3.63) were associated with increased risk. HRs for infection were similar with either <24 h or <48 h of antibiotic prophylaxis. There was a significant but differential effect of transfusion by surgery type (excluding left ventricular assist device procedures/transplant) (HR: 1.13; 95% CI: 1.07 to 1.20). Major infections substantially increased mortality (HR: 10.02; 95% CI: 6.12 to 16.39).

Conclusions: Major infections dramatically affect survival and readmissions. Second-generation cephalosporins were strongly associated with reduced major infection risk, but optimal duration of antibiotic prophylaxis requires further study. Given practice variations, considerable opportunities exist for improving outcomes and preventing readmissions. (Management Practices and Risk of Infection Following Cardiac Surgery; NCT01089712).

Keywords: cardiac surgery; infection; risk factors.

Figure 1. Mantel Byar Survival Curve

97 deaths occurred over the 65-day post-surgery follow-up period.

Central Illustration. Infection Risk Factors and SCIP measure Compliance

SCIP, Surgical Care Improvement Project; CEPH, cephalosporin; PRBC, packed red blood cells; LVAD/Tx, left ventricular assist device or transplant surgery; ABx is antibiotics; hyperglycemic episode is >180 mg/dl; vanco is vancomycin. Figure 1 was adjusted for baseline patient and procedure risk factors.