Timing of preoperative antibiotic prophylaxis - A modifiable risk factor for deep surgical site infections after pediatric spinal fusion

Background: Deep surgical site infections (SSI) after spinal fusion are healthcare-associated infections that result in increased morbidity, hospital stay, and health care costs. Risk factors for these infections among children are poorly characterized. Methods: We performed a case-control study nested within a cohort of all children, from birth to 18 years of age, who underwent spinal fusion at Johns Hopkins Hospital between July 1, 2000 and June 30, 2006. Results: Thirty-six deep SSI were identified. The incidence of deep SSI was 3.4%. Infection was diagnosed a median of 15 days after surgery (interquartile range, 9-28). Significant risk factors for deep SSI included inappropriate timing of preoperative antibiotic prophylaxis, previous spine surgery, presence of a complex underlying medical condition, age, > 10 vertebrae fused, and an increased estimated blood loss per kilogram body weight. After controlling for previous spine surgery, number of vertebrae fused, and complex underlying medical condition, inappropriate timing of preoperative antibiotic prophylaxis administration was a significant independent risk factor for deep SSI (odds ratio: 3.5; 95% confidence interval: 1.7-7.3; P = 0.001). Discussion: Timing of preoperative antibiotic prophylaxis is an independent and modifiable risk factor for deep SSI after pediatric spinal fusion. Our findings suggest that all pediatric patients undergoing pediatric spinal fusion should have preoperative antibiotic prophylaxis given within 60 minutes before incision to reduce the risk of SSI and the morbidity and costs associated with hardware removal and repeat spinal fusion.