AbstractsMedical & Health Science

<b>Objective:</b> To identify risk factors associated with pediatric spinal fusion surgical site infection (SSI). <b>Design:</b> Retrospective case-control study nested within a hospital cohort. <b>Setting:</b> A 475-bed, tertiary children's hospital. <b>Methods:</b> All patients undergoing a posterior spinal fusion from January 1995- December 2006 were included. SSI cases were identified by prospective surveillance using National Nosocomial Infection Surveillance System (NNIS) definitions. Forty-four cases were identified and matched to 3 uninfected controls with matching based on date of surgery (+/- 3 months). SSI risk factors were evaluated by univariate analysis and multivariable conditional logistic regression. Odds ratios (OR) with 95% confidence intervals (CI) and P values were calculated. <b>Results:</b> The average of the annual spinal fusion SSI rates was 4.4%. Significant factors in the univariate analysis included: body mass index (BMI) percentile >95% (OR=3.5; CI 1.5-8.3), antibiotic prophylaxis with clindamycin compared to other antibiotics (OR=3.5; CI 1.2-10.0), inappropriately low antibiotic dosage (OR=2.6; CI 1.0-6.6) and hypothermia (<35.5°C) for a longer percentage of the operative time, (OR=0.4; CI 0.2-0.9). An American Society of Anesthesiologists (ASA) score >2, obesity (BMI percentile >95%), antibiotic prophylaxis with clindamycin and hypothermia were statistically significant in the multivariable model. <b>Conclusion:</b> An ASA score >2, obesity and antibiotic prophylaxis with clindamycin were independent risk factors for infection. Hypothermia during surgery appears to be protective against infection in this population.